#include "fts3.h"
#ifndef SQLITE_CORE 
# include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#endif



/* TODO(shess) MAN, this thing needs some refactoring.  At minimum, it
** would be nice to order the file better, perhaps something along the
** lines of:
**
**  - utility functions
**  - table setup functions
**  - table update functions
**  - table query functions
**
** Put the query functions last because they're likely to reference
** typedefs or functions from the table update section.
*/

#if 0
# define FTSTRACE(A)  printf A; fflush(stdout)
#else
# define FTSTRACE(A)
#endif

typedef enum DocListType {
  DL_DOCIDS,              /* docids only */
  DL_POSITIONS,           /* docids + positions */
  DL_POSITIONS_OFFSETS    /* docids + positions + offsets */
} DocListType;

/*
** By default, only positions and not offsets are stored in the doclists.
** To change this so that offsets are stored too, compile with
**
**          -DDL_DEFAULT=DL_POSITIONS_OFFSETS
**
** If DL_DEFAULT is set to DL_DOCIDS, your table can only be inserted
** into (no deletes or updates).
*/
#ifndef DL_DEFAULT
# define DL_DEFAULT DL_POSITIONS
#endif

enum {
  POS_END = 0,        /* end of this position list */
  POS_COLUMN,         /* followed by new column number */
  POS_BASE
};

/* utility functions */

/* CLEAR() and SCRAMBLE() abstract memset() on a pointer to a single
** record to prevent errors of the form:
**
** my_function(SomeType *b){
**   memset(b, '\0', sizeof(b));  // sizeof(b)!=sizeof(*b)
** }
*/
/* TODO(shess) Obvious candidates for a header file. */
#define CLEAR(b) memset(b, '\0', sizeof(*(b)))

#ifndef NDEBUG
#  define SCRAMBLE(b) memset(b, 0x55, sizeof(*(b)))
#else
#  define SCRAMBLE(b)
#endif

/* 
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
** The number of bytes written is returned.
*/
int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
  unsigned char *q = (unsigned char *) p;
................................................................................
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read, or 0 on error.
** The value is stored in *v.
*/
int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
  const unsigned char *q = (const unsigned char *) p;
  sqlite_uint64 x = 0, y = 1;
  while( (*q & 0x80) == 0x80 ){
    x += y * (*q++ & 0x7f);
    y <<= 7;
    if( q - (unsigned char *)p >= FTS3_VARINT_MAX ){  /* bad data */
      assert( 0 );
      return 0;
    }
  }
  x += y * (*q++);
  *v = (sqlite_int64) x;
  return (int) (q - (unsigned char *)p);
}

/*
................................................................................
** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to a
** 32-bit integer before it is returned.
*/
int sqlite3Fts3GetVarint32(const char *p, int *pi){
 sqlite_int64 i;
 int ret = sqlite3Fts3GetVarint(p, &i);
 *pi = (int) i;
 assert( *pi==i );
 return ret;
}

/*
** Return the number of bytes required to store the value passed as the
** first argument in varint form.
*/
................................................................................
**
** Examples:
**
**     "abc"   becomes   abc
**     'xyz'   becomes   xyz
**     [pqr]   becomes   pqr
**     `mno`   becomes   mno

*/
void sqlite3Fts3Dequote(char *z){
  int quote;
  int i, j;

  quote = z[0];
  switch( quote ){
    case '\'':  break;
    case '"':   break;
    case '`':   break;                /* For MySQL compatibility */

    case '[':   quote = ']';  break;  /* For MS SqlServer compatibility */
    default:    return;
  }
  for(i=1, j=0; z[i]; i++){
    if( z[i]==quote ){
      if( z[i+1]==quote ){
        z[j++] = (char)quote;
        i++;
      }else{
        z[j++] = 0;
        break;
      }
    }else{
      z[j++] = z[i];
    }

  }
}

static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
  sqlite3_int64 iVal;
  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
  *pVal += iVal;
................................................................................
** The argv[] array contains the following:
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> "column name" and other module argument fields.
*/
int fts3InitVtab(
  int isCreate,                   /* True for xCreate, false for xConnect */
  sqlite3 *db,                    /* The SQLite database connection */
  void *pAux,                     /* Hash table containing tokenizers */
  int argc,                       /* Number of elements in argv array */
  const char * const *argv,       /* xCreate/xConnect argument array */
  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
  char **pzErr                    /* Write any error message here */
................................................................................
  char *zCsr;
  int nDb;
  int nName;

  const char *zTokenizer = 0;               /* Name of tokenizer to use */
  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */

#ifdef SQLITE_TEST
  const char *zTestParam = 0;
  if( strncmp(argv[argc-1], "test:", 5)==0 ){
    zTestParam = argv[argc-1];
    argc--;
  }
#endif

  nDb = (int)strlen(argv[1]) + 1;
  nName = (int)strlen(argv[2]) + 1;
  for(i=3; i<argc; i++){
    char const *z = argv[i];
    rc = sqlite3Fts3InitTokenizer(pHash, z, &pTokenizer, &zTokenizer, pzErr);
    if( rc!=SQLITE_OK ){
      return rc;
................................................................................

  p->db = db;
  p->nColumn = nCol;
  p->nPendingData = 0;
  p->azColumn = (char **)&p[1];
  p->pTokenizer = pTokenizer;
  p->nNodeSize = 1000;

  zCsr = (char *)&p->azColumn[nCol];

  fts3HashInit(&p->pendingTerms, FTS3_HASH_STRING, 1);

  /* Fill in the zName and zDb fields of the vtab structure. */
  p->zName = zCsr;
  memcpy(zCsr, argv[2], nName);
................................................................................
    rc = fts3CreateTables(p);
    if( rc!=SQLITE_OK ) goto fts3_init_out;
  }

  rc = fts3DeclareVtab(p);
  if( rc!=SQLITE_OK ) goto fts3_init_out;

#ifdef SQLITE_TEST
  if( zTestParam ){
    p->nNodeSize = atoi(&zTestParam[5]);
  }
#endif
  *ppVTab = &p->base;

fts3_init_out:
  assert( p || (pTokenizer && rc!=SQLITE_OK) );
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
................................................................................
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 500000;
  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ) continue;

    /* A direct lookup on the rowid or docid column. This is the best
    ** strategy in all cases. Assign a cost of 1.0 and return early.
    */
    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
    ){
      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;
      iCons = i;
      break;
    }

    /* A MATCH constraint. Use a full-text search.
    **
    ** If there is more than one MATCH constraint available, use the first
    ** one encountered. If there is both a MATCH constraint and a direct
    ** rowid/docid lookup, prefer the rowid/docid strategy.



    */
    if( iCons<0 
     && pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
    ){
      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
      pInfo->estimatedCost = 2.0;
      iCons = i;

    }
  }

  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = 1;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
................................................................................
  sqlite3_finalize(pCsr->pStmt);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  sqlite3_free(pCsr->aDoclist);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

static int fts3CursorSeek(Fts3Cursor *pCsr){
  if( pCsr->isRequireSeek ){
    pCsr->isRequireSeek = 0;
    sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
    if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
      return SQLITE_OK;
    }else{
      int rc;
      pCsr->isEof = 1;
      if( SQLITE_OK==(rc = sqlite3_reset(pCsr->pStmt)) ){





        rc = SQLITE_ERROR;




      }
      return rc;
    }
  }else{
    return SQLITE_OK;
  }
}
................................................................................
        if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){
          if( (*p2&0xFE)==0 ) break;
          fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
        }else{
          if( (*p1&0xFE)==0 ) break;
          fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
        }

      }
      if( pSave && pp ){

        p = pSave;
      }

      fts3ColumnlistCopy(0, &p1);
      fts3ColumnlistCopy(0, &p2);
      assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );
      if( 0==*p1 || 0==*p2 ) break;
................................................................................
       || mergetype==MERGE_PHRASE || mergetype==MERGE_POS_PHRASE
       || mergetype==MERGE_NEAR   || mergetype==MERGE_POS_NEAR
  );

  if( !aBuffer ){
    return SQLITE_NOMEM;
  }
  if( n1==0 && n2==0 ){
    *pnBuffer = 0;
    return SQLITE_OK;
  }

  /* Read the first docid from each doclist */
  fts3GetDeltaVarint2(&p1, pEnd1, &i1);
  fts3GetDeltaVarint2(&p2, pEnd2, &i2);

  switch( mergetype ){
    case MERGE_OR:
................................................................................
    }

    default: assert( mergetype==MERGE_POS_NEAR || mergetype==MERGE_NEAR ); {
      char *aTmp = 0;
      char **ppPos = 0;
      if( mergetype==MERGE_POS_NEAR ){
        ppPos = &p;
        aTmp = sqlite3_malloc(2*(n1+n2));
        if( !aTmp ){
          return SQLITE_NOMEM;
        }
      }

      while( p1 && p2 ){
        if( i1==i2 ){
................................................................................
  int isReqPos,                   /* True to include position lists in output */
  int *pnOut,                     /* OUT: Size of buffer at *ppOut */
  char **ppOut                    /* OUT: Malloced result buffer */
){
  int i;
  TermSelect tsc;
  Fts3SegFilter filter;           /* Segment term filter configuration */
  Fts3SegReader **apSegment = 0;  /* Array of segments to read data from */
  int nSegment = 0;               /* Size of apSegment array */
  int nAlloc = 0;                 /* Allocated size of segment array */
  int rc;                         /* Return code */
  sqlite3_stmt *pStmt;            /* SQL statement to scan %_segdir table */
  int iAge = 0;                   /* Used to assign ages to segments */









  /* Loop through the entire %_segdir table. For each segment, create a
  ** Fts3SegReader to iterate through the subset of the segment leaves
  ** that may contain a term that matches zTerm/nTerm. For non-prefix
  ** searches, this is always a single leaf. For prefix searches, this
  ** may be a contiguous block of leaves.
  **
................................................................................
  char *pOut = 0;
  int nOut = 0;
  int rc = SQLITE_OK;
  int ii;
  int iCol = pPhrase->iColumn;
  int isTermPos = (pPhrase->nToken>1 || isReqPos);

  assert( p->nPendingData==0 );

  for(ii=0; ii<pPhrase->nToken; ii++){
    struct PhraseToken *pTok = &pPhrase->aToken[ii];
    char *z = pTok->z;            /* Next token of the phrase */
    int n = pTok->n;              /* Size of z in bytes */
    int isPrefix = pTok->isPrefix;/* True if token is a prefix */
    char *pList;                  /* Pointer to token doclist */
    int nList;                    /* Size of buffer at pList */
................................................................................
  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( nVal==0 || nVal==1 );
  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);

  memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));

  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
  ** statement loops through all rows of the %_content table. For a
  ** full-text query or docid lookup, the statement retrieves a single
  ** row by docid.
  */
................................................................................
  }else if( idxNum!=FTS3_FULLSCAN_SEARCH ){
    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }
    rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;

    rc = sqlite3Fts3ExprParse(p->pTokenizer, p->azColumn, p->nColumn, 
        iCol, zQuery, -1, &pCsr->pExpr
    );
    if( rc!=SQLITE_OK ) return rc;

    rc = evalFts3Expr(p, pCsr->pExpr, &pCsr->aDoclist, &pCsr->nDoclist);
................................................................................
  int rc;                         /* Return Code */
  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  /* The column value supplied by SQLite must be in range. */
  assert( iCol>=0 && iCol<=p->nColumn+1 );

  rc = fts3CursorSeek(pCsr);
  if( rc==SQLITE_OK ){
    if( iCol==p->nColumn+1 ){
      /* This call is a request for the "docid" column. Since "docid" is an 
      ** alias for "rowid", use the xRowid() method to obtain the value.
      */
      sqlite3_int64 iRowid;
      rc = fts3RowidMethod(pCursor, &iRowid);
      sqlite3_result_int64(pContext, iRowid);
    }else if( iCol==p->nColumn ){
      /* The extra column whose name is the same as the table.
      ** Return a blob which is a pointer to the cursor.
      */
      sqlite3_result_blob(pContext, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);

    }else{


      sqlite3_result_value(pContext, sqlite3_column_value(pCsr->pStmt, iCol+1));
    }
  }
  return rc;
}

/* 
................................................................................
  if( fts3FunctionArg(pContext, "snippet", apVal[0], &pCsr) ) return;

  switch( nVal ){
    case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);
    case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);
    case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);
  }




  sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis);

}

/*
** Implementation of the offsets() function for FTS3
*/
static void fts3OffsetsFunc(
  sqlite3_context *pContext,      /* SQLite function call context */
................................................................................
  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  UNUSED_PARAMETER(nVal);

  assert( nVal==1 );
  if( fts3FunctionArg(pContext, "offsets", apVal[0], &pCsr) ) return;
  assert( pCsr );

  sqlite3Fts3Offsets(pContext, pCsr);

}

/* 
** Implementation of the special optimize() function for FTS3. This 
** function merges all segments in the database to a single segment.
** Example usage is:
**
................................................................................
** function is called by the sqlite3_extension_init() entry point.
*/
int sqlite3Fts3Init(sqlite3 *db){
  int rc = SQLITE_OK;
  Fts3Hash *pHash = 0;
  const sqlite3_tokenizer_module *pSimple = 0;
  const sqlite3_tokenizer_module *pPorter = 0;


  const sqlite3_tokenizer_module *pIcu = 0;



  sqlite3Fts3SimpleTokenizerModule(&pSimple);
  sqlite3Fts3PorterTokenizerModule(&pPorter);
#ifdef SQLITE_ENABLE_ICU
  sqlite3Fts3IcuTokenizerModule(&pIcu);
#endif

  /* Allocate and initialise the hash-table used to store tokenizers. */
  pHash = sqlite3_malloc(sizeof(Fts3Hash));
  if( !pHash ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
  }

  /* Load the built-in tokenizers into the hash table */
  if( rc==SQLITE_OK ){
    if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)
     || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 

     || (pIcu && sqlite3Fts3HashInsert(pHash, "icu", 4, (void *)pIcu))

    ){
      rc = SQLITE_NOMEM;
    }
  }

#ifdef SQLITE_TEST

  sqlite3Fts3ExprInitTestInterface(db);

#endif

  /* Create the virtual table wrapper around the hash-table and overload 
  ** the two scalar functions. If this is successful, register the
  ** module with sqlite.
  */
  if( SQLITE_OK==rc 

#include "fts3.h"
#ifndef SQLITE_CORE 
# include "sqlite3ext.h"
  SQLITE_EXTENSION_INIT1
#endif

































































/* 
** Write a 64-bit variable-length integer to memory starting at p[0].
** The length of data written will be between 1 and FTS3_VARINT_MAX bytes.
** The number of bytes written is returned.
*/
int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
  unsigned char *q = (unsigned char *) p;
................................................................................
** Read a 64-bit variable-length integer from memory starting at p[0].
** Return the number of bytes read, or 0 on error.
** The value is stored in *v.
*/
int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
  const unsigned char *q = (const unsigned char *) p;
  sqlite_uint64 x = 0, y = 1;
  while( (*q&0x80)==0x80 && q-(unsigned char *)p<FTS3_VARINT_MAX ){
    x += y * (*q++ & 0x7f);
    y <<= 7;




  }
  x += y * (*q++);
  *v = (sqlite_int64) x;
  return (int) (q - (unsigned char *)p);
}

/*
................................................................................
** Similar to sqlite3Fts3GetVarint(), except that the output is truncated to a
** 32-bit integer before it is returned.
*/
int sqlite3Fts3GetVarint32(const char *p, int *pi){
 sqlite_int64 i;
 int ret = sqlite3Fts3GetVarint(p, &i);
 *pi = (int) i;

 return ret;
}

/*
** Return the number of bytes required to store the value passed as the
** first argument in varint form.
*/
................................................................................
**
** Examples:
**
**     "abc"   becomes   abc
**     'xyz'   becomes   xyz
**     [pqr]   becomes   pqr
**     `mno`   becomes   mno
**
*/
void sqlite3Fts3Dequote(char *z){

  char quote;                     /* Quote character (if any ) */

  quote = z[0];
  if( quote=='[' || quote=='\'' || quote=='"' || quote=='`' ){
    int iIn = 1;                  /* Index of next byte to read from input */
    int iOut = 0;                 /* Index of next byte to write to output */


    /* If the first byte was a '[', then the close-quote character is a ']' */
    if( quote=='[' ) quote = ']';  

    while( ALWAYS(z[iIn]) ){
      if( z[iIn]==quote ){
        if( z[iIn+1]!=quote ) break;
        z[iOut++] = quote;
        iIn += 2;
      }else{
        z[iOut++] = z[iIn++];

      }


    }
    z[iOut] = '\0';
  }
}

static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
  sqlite3_int64 iVal;
  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
  *pVal += iVal;
................................................................................
** The argv[] array contains the following:
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> "column name" and other module argument fields.
*/
static int fts3InitVtab(
  int isCreate,                   /* True for xCreate, false for xConnect */
  sqlite3 *db,                    /* The SQLite database connection */
  void *pAux,                     /* Hash table containing tokenizers */
  int argc,                       /* Number of elements in argv array */
  const char * const *argv,       /* xCreate/xConnect argument array */
  sqlite3_vtab **ppVTab,          /* Write the resulting vtab structure here */
  char **pzErr                    /* Write any error message here */
................................................................................
  char *zCsr;
  int nDb;
  int nName;

  const char *zTokenizer = 0;               /* Name of tokenizer to use */
  sqlite3_tokenizer *pTokenizer = 0;        /* Tokenizer for this table */









  nDb = (int)strlen(argv[1]) + 1;
  nName = (int)strlen(argv[2]) + 1;
  for(i=3; i<argc; i++){
    char const *z = argv[i];
    rc = sqlite3Fts3InitTokenizer(pHash, z, &pTokenizer, &zTokenizer, pzErr);
    if( rc!=SQLITE_OK ){
      return rc;
................................................................................

  p->db = db;
  p->nColumn = nCol;
  p->nPendingData = 0;
  p->azColumn = (char **)&p[1];
  p->pTokenizer = pTokenizer;
  p->nNodeSize = 1000;
  p->nMaxPendingData = FTS3_MAX_PENDING_DATA;
  zCsr = (char *)&p->azColumn[nCol];

  fts3HashInit(&p->pendingTerms, FTS3_HASH_STRING, 1);

  /* Fill in the zName and zDb fields of the vtab structure. */
  p->zName = zCsr;
  memcpy(zCsr, argv[2], nName);
................................................................................
    rc = fts3CreateTables(p);
    if( rc!=SQLITE_OK ) goto fts3_init_out;
  }

  rc = fts3DeclareVtab(p);
  if( rc!=SQLITE_OK ) goto fts3_init_out;






  *ppVTab = &p->base;

fts3_init_out:
  assert( p || (pTokenizer && rc!=SQLITE_OK) );
  if( rc!=SQLITE_OK ){
    if( p ){
      fts3DisconnectMethod((sqlite3_vtab *)p);
................................................................................
  */
  pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
  pInfo->estimatedCost = 500000;
  for(i=0; i<pInfo->nConstraint; i++){
    struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
    if( pCons->usable==0 ) continue;

    /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */


    if( pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
    ){
      pInfo->idxNum = FTS3_DOCID_SEARCH;
      pInfo->estimatedCost = 1.0;
      iCons = i;

    }

    /* A MATCH constraint. Use a full-text search.
    **
    ** If there is more than one MATCH constraint available, use the first
    ** one encountered. If there is both a MATCH constraint and a direct
    ** rowid/docid lookup, prefer the MATCH strategy. This is done even 
    ** though the rowid/docid lookup is faster than a MATCH query, selecting
    ** it would lead to an "unable to use function MATCH in the requested 
    ** context" error.
    */

    if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH 
     && pCons->iColumn>=0 && pCons->iColumn<=p->nColumn
    ){
      pInfo->idxNum = FTS3_FULLTEXT_SEARCH + pCons->iColumn;
      pInfo->estimatedCost = 2.0;
      iCons = i;
      break;
    }
  }

  if( iCons>=0 ){
    pInfo->aConstraintUsage[iCons].argvIndex = 1;
    pInfo->aConstraintUsage[iCons].omit = 1;
  } 
................................................................................
  sqlite3_finalize(pCsr->pStmt);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  sqlite3_free(pCsr->aDoclist);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

static int fts3CursorSeek(sqlite3_context *pContext, Fts3Cursor *pCsr){
  if( pCsr->isRequireSeek ){
    pCsr->isRequireSeek = 0;
    sqlite3_bind_int64(pCsr->pStmt, 1, pCsr->iPrevId);
    if( SQLITE_ROW==sqlite3_step(pCsr->pStmt) ){
      return SQLITE_OK;
    }else{


      int rc = sqlite3_reset(pCsr->pStmt);
      if( rc==SQLITE_OK ){
        /* If no row was found and no error has occured, then the %_content
        ** table is missing a row that is present in the full-text index.
        ** The data structures are corrupt.
        */
        rc = SQLITE_CORRUPT;
      }
      pCsr->isEof = 1;
      if( pContext ){
        sqlite3_result_error_code(pContext, rc);
      }
      return rc;
    }
  }else{
    return SQLITE_OK;
  }
}
................................................................................
        if( (!isSaveLeft && iPos2<=(iPos1+nToken)) || iPos2<=iPos1 ){
          if( (*p2&0xFE)==0 ) break;
          fts3GetDeltaVarint(&p2, &iPos2); iPos2 -= 2;
        }else{
          if( (*p1&0xFE)==0 ) break;
          fts3GetDeltaVarint(&p1, &iPos1); iPos1 -= 2;
        }
      }

      if( pSave ){
        assert( pp && p );
        p = pSave;
      }

      fts3ColumnlistCopy(0, &p1);
      fts3ColumnlistCopy(0, &p2);
      assert( (*p1&0xFE)==0 && (*p2&0xFE)==0 );
      if( 0==*p1 || 0==*p2 ) break;
................................................................................
       || mergetype==MERGE_PHRASE || mergetype==MERGE_POS_PHRASE
       || mergetype==MERGE_NEAR   || mergetype==MERGE_POS_NEAR
  );

  if( !aBuffer ){
    return SQLITE_NOMEM;
  }





  /* Read the first docid from each doclist */
  fts3GetDeltaVarint2(&p1, pEnd1, &i1);
  fts3GetDeltaVarint2(&p2, pEnd2, &i2);

  switch( mergetype ){
    case MERGE_OR:
................................................................................
    }

    default: assert( mergetype==MERGE_POS_NEAR || mergetype==MERGE_NEAR ); {
      char *aTmp = 0;
      char **ppPos = 0;
      if( mergetype==MERGE_POS_NEAR ){
        ppPos = &p;
        aTmp = sqlite3_malloc(2*(n1+n2+1));
        if( !aTmp ){
          return SQLITE_NOMEM;
        }
      }

      while( p1 && p2 ){
        if( i1==i2 ){
................................................................................
  int isReqPos,                   /* True to include position lists in output */
  int *pnOut,                     /* OUT: Size of buffer at *ppOut */
  char **ppOut                    /* OUT: Malloced result buffer */
){
  int i;
  TermSelect tsc;
  Fts3SegFilter filter;           /* Segment term filter configuration */
  Fts3SegReader **apSegment;      /* Array of segments to read data from */
  int nSegment = 0;               /* Size of apSegment array */
  int nAlloc = 16;                /* Allocated size of segment array */
  int rc;                         /* Return code */
  sqlite3_stmt *pStmt = 0;        /* SQL statement to scan %_segdir table */
  int iAge = 0;                   /* Used to assign ages to segments */

  apSegment = (Fts3SegReader **)sqlite3_malloc(sizeof(Fts3SegReader*)*nAlloc);
  if( !apSegment ) return SQLITE_NOMEM;
  rc = sqlite3Fts3SegReaderPending(p, zTerm, nTerm, isPrefix, &apSegment[0]);
  if( rc!=SQLITE_OK ) goto finished;
  if( apSegment[0] ){
    nSegment = 1;
  }

  /* Loop through the entire %_segdir table. For each segment, create a
  ** Fts3SegReader to iterate through the subset of the segment leaves
  ** that may contain a term that matches zTerm/nTerm. For non-prefix
  ** searches, this is always a single leaf. For prefix searches, this
  ** may be a contiguous block of leaves.
  **
................................................................................
  char *pOut = 0;
  int nOut = 0;
  int rc = SQLITE_OK;
  int ii;
  int iCol = pPhrase->iColumn;
  int isTermPos = (pPhrase->nToken>1 || isReqPos);



  for(ii=0; ii<pPhrase->nToken; ii++){
    struct PhraseToken *pTok = &pPhrase->aToken[ii];
    char *z = pTok->z;            /* Next token of the phrase */
    int n = pTok->n;              /* Size of z in bytes */
    int isPrefix = pTok->isPrefix;/* True if token is a prefix */
    char *pList;                  /* Pointer to token doclist */
    int nList;                    /* Size of buffer at pList */
................................................................................
  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
  assert( nVal==0 || nVal==1 );
  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );

  /* In case the cursor has been used before, clear it now. */
  sqlite3_finalize(pCsr->pStmt);
  sqlite3_free(pCsr->aDoclist);
  sqlite3Fts3ExprFree(pCsr->pExpr);
  memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));

  /* Compile a SELECT statement for this cursor. For a full-table-scan, the
  ** statement loops through all rows of the %_content table. For a
  ** full-text query or docid lookup, the statement retrieves a single
  ** row by docid.
  */
................................................................................
  }else if( idxNum!=FTS3_FULLSCAN_SEARCH ){
    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);

    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
      return SQLITE_NOMEM;
    }



    rc = sqlite3Fts3ExprParse(p->pTokenizer, p->azColumn, p->nColumn, 
        iCol, zQuery, -1, &pCsr->pExpr
    );
    if( rc!=SQLITE_OK ) return rc;

    rc = evalFts3Expr(p, pCsr->pExpr, &pCsr->aDoclist, &pCsr->nDoclist);
................................................................................
  int rc;                         /* Return Code */
  Fts3Cursor *pCsr = (Fts3Cursor *) pCursor;
  Fts3Table *p = (Fts3Table *)pCursor->pVtab;

  /* The column value supplied by SQLite must be in range. */
  assert( iCol>=0 && iCol<=p->nColumn+1 );



  if( iCol==p->nColumn+1 ){
    /* This call is a request for the "docid" column. Since "docid" is an 
    ** alias for "rowid", use the xRowid() method to obtain the value.
    */
    sqlite3_int64 iRowid;
    rc = fts3RowidMethod(pCursor, &iRowid);
    sqlite3_result_int64(pContext, iRowid);
  }else if( iCol==p->nColumn ){
    /* The extra column whose name is the same as the table.
    ** Return a blob which is a pointer to the cursor.
    */
    sqlite3_result_blob(pContext, &pCsr, sizeof(pCsr), SQLITE_TRANSIENT);
    rc = SQLITE_OK;
  }else{
    rc = fts3CursorSeek(0, pCsr);
    if( rc==SQLITE_OK ){
      sqlite3_result_value(pContext, sqlite3_column_value(pCsr->pStmt, iCol+1));
    }
  }
  return rc;
}

/* 
................................................................................
  if( fts3FunctionArg(pContext, "snippet", apVal[0], &pCsr) ) return;

  switch( nVal ){
    case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);
    case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);
    case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);
  }

  if( !zEllipsis || !zEnd || !zStart ){
    sqlite3_result_error_nomem(pContext);
  }else if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
    sqlite3Fts3Snippet(pContext, pCsr, zStart, zEnd, zEllipsis);
  }
}

/*
** Implementation of the offsets() function for FTS3
*/
static void fts3OffsetsFunc(
  sqlite3_context *pContext,      /* SQLite function call context */
................................................................................
  Fts3Cursor *pCsr;               /* Cursor handle passed through apVal[0] */

  UNUSED_PARAMETER(nVal);

  assert( nVal==1 );
  if( fts3FunctionArg(pContext, "offsets", apVal[0], &pCsr) ) return;
  assert( pCsr );
  if( SQLITE_OK==fts3CursorSeek(pContext, pCsr) ){
    sqlite3Fts3Offsets(pContext, pCsr);
  }
}

/* 
** Implementation of the special optimize() function for FTS3. This 
** function merges all segments in the database to a single segment.
** Example usage is:
**
................................................................................
** function is called by the sqlite3_extension_init() entry point.
*/
int sqlite3Fts3Init(sqlite3 *db){
  int rc = SQLITE_OK;
  Fts3Hash *pHash = 0;
  const sqlite3_tokenizer_module *pSimple = 0;
  const sqlite3_tokenizer_module *pPorter = 0;

#ifdef SQLITE_ENABLE_ICU
  const sqlite3_tokenizer_module *pIcu = 0;
  sqlite3Fts3IcuTokenizerModule(&pIcu);
#endif

  sqlite3Fts3SimpleTokenizerModule(&pSimple);
  sqlite3Fts3PorterTokenizerModule(&pPorter);




  /* Allocate and initialise the hash-table used to store tokenizers. */
  pHash = sqlite3_malloc(sizeof(Fts3Hash));
  if( !pHash ){
    rc = SQLITE_NOMEM;
  }else{
    sqlite3Fts3HashInit(pHash, FTS3_HASH_STRING, 1);
  }

  /* Load the built-in tokenizers into the hash table */
  if( rc==SQLITE_OK ){
    if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)
     || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 
#ifdef SQLITE_ENABLE_ICU
     || (pIcu && sqlite3Fts3HashInsert(pHash, "icu", 4, (void *)pIcu))
#endif
    ){
      rc = SQLITE_NOMEM;
    }
  }

#ifdef SQLITE_TEST
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3ExprInitTestInterface(db);
  }
#endif

  /* Create the virtual table wrapper around the hash-table and overload 
  ** the two scalar functions. If this is successful, register the
  ** module with sqlite.
  */
  if( SQLITE_OK==rc 

  sqlite3_stmt **aLeavesStmt;     /* Array of prepared zSelectLeaves stmts */

  int nNodeSize;                  /* Soft limit for node size */

  /* The following hash table is used to buffer pending index updates during
  ** transactions. Variable nPendingData estimates the memory size of the 
  ** pending data, including hash table overhead, but not malloc overhead. 
  ** When nPendingData exceeds FTS3_MAX_PENDING_DATA, the buffer is flushed 
  ** automatically. Variable iPrevDocid is the docid of the most recently
  ** inserted record.
  */

  int nPendingData;
  sqlite_int64 iPrevDocid;
  Fts3Hash pendingTerms;
};

/*
** When the core wants to read from the virtual table, it creates a
................................................................................
/* fts3_write.c */
int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
int sqlite3Fts3PendingTermsFlush(Fts3Table *);
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(Fts3Table *,int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);

void sqlite3Fts3SegReaderFree(Fts3Table *, Fts3SegReader *);
int sqlite3Fts3SegReaderIterate(
  Fts3Table *, Fts3SegReader **, int, Fts3SegFilter *,
  int (*)(Fts3Table *, void *, char *, int, char *, int),  void *
);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char const**, int*);
int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
................................................................................

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
  char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
void sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif

#endif /* _FTSINT_H */

  sqlite3_stmt **aLeavesStmt;     /* Array of prepared zSelectLeaves stmts */

  int nNodeSize;                  /* Soft limit for node size */

  /* The following hash table is used to buffer pending index updates during
  ** transactions. Variable nPendingData estimates the memory size of the 
  ** pending data, including hash table overhead, but not malloc overhead. 
  ** When nPendingData exceeds nMaxPendingData, the buffer is flushed 
  ** automatically. Variable iPrevDocid is the docid of the most recently
  ** inserted record.
  */
  int nMaxPendingData;
  int nPendingData;
  sqlite_int64 iPrevDocid;
  Fts3Hash pendingTerms;
};

/*
** When the core wants to read from the virtual table, it creates a
................................................................................
/* fts3_write.c */
int sqlite3Fts3UpdateMethod(sqlite3_vtab*,int,sqlite3_value**,sqlite3_int64*);
int sqlite3Fts3PendingTermsFlush(Fts3Table *);
void sqlite3Fts3PendingTermsClear(Fts3Table *);
int sqlite3Fts3Optimize(Fts3Table *);
int sqlite3Fts3SegReaderNew(Fts3Table *,int, sqlite3_int64,
  sqlite3_int64, sqlite3_int64, const char *, int, Fts3SegReader**);
int sqlite3Fts3SegReaderPending(Fts3Table*,const char*,int,int,Fts3SegReader**);
void sqlite3Fts3SegReaderFree(Fts3Table *, Fts3SegReader *);
int sqlite3Fts3SegReaderIterate(
  Fts3Table *, Fts3SegReader **, int, Fts3SegFilter *,
  int (*)(Fts3Table *, void *, char *, int, char *, int),  void *
);
int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char const**, int*);
int sqlite3Fts3AllSegdirs(Fts3Table*, sqlite3_stmt **);
................................................................................

/* fts3_expr.c */
int sqlite3Fts3ExprParse(sqlite3_tokenizer *, 
  char **, int, int, const char *, int, Fts3Expr **
);
void sqlite3Fts3ExprFree(Fts3Expr *);
#ifdef SQLITE_TEST
int sqlite3Fts3ExprInitTestInterface(sqlite3 *db);
#endif

#endif /* _FTSINT_H */

}


/*
** Enlarge a memory allocation.  If an out-of-memory allocation occurs,
** then free the old allocation.
*/
void *fts3ReallocOrFree(void *pOrig, int nNew){
  void *pRet = sqlite3_realloc(pOrig, nNew);
  if( !pRet ){
    sqlite3_free(pOrig);
  }
  return pRet;
}

................................................................................
  sqlite3_free(azCol);
}

/*
** Register the query expression parser test function fts3_exprtest() 
** with database connection db. 
*/
void sqlite3Fts3ExprInitTestInterface(sqlite3* db){
  sqlite3_create_function(
      db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
  );
}

#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

}


/*
** Enlarge a memory allocation.  If an out-of-memory allocation occurs,
** then free the old allocation.
*/
static void *fts3ReallocOrFree(void *pOrig, int nNew){
  void *pRet = sqlite3_realloc(pOrig, nNew);
  if( !pRet ){
    sqlite3_free(pOrig);
  }
  return pRet;
}

................................................................................
  sqlite3_free(azCol);
}

/*
** Register the query expression parser test function fts3_exprtest() 
** with database connection db. 
*/
int sqlite3Fts3ExprInitTestInterface(sqlite3* db){
  return sqlite3_create_function(
      db, "fts3_exprtest", -1, SQLITE_UTF8, 0, fts3ExprTest, 0, 0
  );
}

#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

  if( pH->count<=0 ){
    assert( pH->first==0 );
    assert( pH->count==0 );
    fts3HashClear(pH);
  }
}

/* Attempt to locate an element of the hash table pH with a key
** that matches pKey,nKey.  Return the data for this element if it is
** found, or NULL if there is no match.
*/
void *sqlite3Fts3HashFind(const Fts3Hash *pH, const void *pKey, int nKey){
  int h;                 /* A hash on key */
  Fts3HashElem *elem;    /* The element that matches key */
  int (*xHash)(const void*,int);  /* The hash function */

  if( pH==0 || pH->ht==0 ) return 0;
  xHash = ftsHashFunction(pH->keyClass);
  assert( xHash!=0 );
  h = (*xHash)(pKey,nKey);
  assert( (pH->htsize & (pH->htsize-1))==0 );
  elem = fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1));











  return elem ? elem->data : 0;
}

/* Insert an element into the hash table pH.  The key is pKey,nKey
** and the data is "data".
**
** If no element exists with a matching key, then a new
** element is created.  A copy of the key is made if the copyKey

  if( pH->count<=0 ){
    assert( pH->first==0 );
    assert( pH->count==0 );
    fts3HashClear(pH);
  }
}

Fts3HashElem *sqlite3Fts3HashFindElem(
  const Fts3Hash *pH, 
  const void *pKey, 
  int nKey
){
  int h;                          /* A hash on key */

  int (*xHash)(const void*,int);  /* The hash function */

  if( pH==0 || pH->ht==0 ) return 0;
  xHash = ftsHashFunction(pH->keyClass);
  assert( xHash!=0 );
  h = (*xHash)(pKey,nKey);
  assert( (pH->htsize & (pH->htsize-1))==0 );
  return fts3FindElementByHash(pH,pKey,nKey, h & (pH->htsize-1));
}

/* 
** Attempt to locate an element of the hash table pH with a key
** that matches pKey,nKey.  Return the data for this element if it is
** found, or NULL if there is no match.
*/
void *sqlite3Fts3HashFind(const Fts3Hash *pH, const void *pKey, int nKey){
  Fts3HashElem *pElem;            /* The element that matches key (if any) */

  pElem = sqlite3Fts3HashFindElem(pH, pKey, nKey);
  return pElem ? pElem->data : 0;
}

/* Insert an element into the hash table pH.  The key is pKey,nKey
** and the data is "data".
**
** If no element exists with a matching key, then a new
** element is created.  A copy of the key is made if the copyKey

/*
** Access routines.  To delete, insert a NULL pointer.
*/
void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey);
void *sqlite3Fts3HashInsert(Fts3Hash*, const void *pKey, int nKey, void *pData);
void *sqlite3Fts3HashFind(const Fts3Hash*, const void *pKey, int nKey);
void sqlite3Fts3HashClear(Fts3Hash*);


/*
** Shorthand for the functions above
*/
#define fts3HashInit   sqlite3Fts3HashInit
#define fts3HashInsert sqlite3Fts3HashInsert
#define fts3HashFind   sqlite3Fts3HashFind
#define fts3HashClear  sqlite3Fts3HashClear


/*
** Macros for looping over all elements of a hash table.  The idiom is
** like this:
**
**   Fts3Hash h;
**   Fts3HashElem *p;

/*
** Access routines.  To delete, insert a NULL pointer.
*/
void sqlite3Fts3HashInit(Fts3Hash *pNew, char keyClass, char copyKey);
void *sqlite3Fts3HashInsert(Fts3Hash*, const void *pKey, int nKey, void *pData);
void *sqlite3Fts3HashFind(const Fts3Hash*, const void *pKey, int nKey);
void sqlite3Fts3HashClear(Fts3Hash*);
Fts3HashElem *sqlite3Fts3HashFindElem(const Fts3Hash *, const void *, int);

/*
** Shorthand for the functions above
*/
#define fts3HashInit     sqlite3Fts3HashInit
#define fts3HashInsert   sqlite3Fts3HashInsert
#define fts3HashFind     sqlite3Fts3HashFind
#define fts3HashClear    sqlite3Fts3HashClear
#define fts3HashFindElem sqlite3Fts3HashFindElem

/*
** Macros for looping over all elements of a hash table.  The idiom is
** like this:
**
**   Fts3Hash h;
**   Fts3HashElem *p;

const char *sqlite3Fts3NextToken(const char *zStr, int *pn){
  const char *z1;
  const char *z2 = 0;

  /* Find the start of the next token. */
  z1 = zStr;
  while( z2==0 ){

    switch( *z1 ){
      case '\0': return 0;        /* No more tokens here */
      case '\'':
      case '"':
      case '`': {
        z2 = &z1[1];
        while( *z2 && (z2[0]!=*z1 || z2[1]==*z1) ) z2++;
        if( *z2 ) z2++;
        break;
      }
      case '[':
        z2 = &z1[1];
        while( *z2 && z2[0]!=']' ) z2++;
        if( *z2 ) z2++;
        break;
................................................................................
  sqlite3 *db, 
  Fts3Hash *pHash, 
  const char *zName
){
  int rc = SQLITE_OK;
  void *p = (void *)pHash;
  const int any = SQLITE_ANY;
  char *zTest = 0;
  char *zTest2 = 0;

#ifdef SQLITE_TEST


  void *pdb = (void *)db;
  zTest = sqlite3_mprintf("%s_test", zName);
  zTest2 = sqlite3_mprintf("%s_internal_test", zName);
  if( !zTest || !zTest2 ){
    rc = SQLITE_NOMEM;
  }
#endif
................................................................................
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0))
#ifdef SQLITE_TEST
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0))
#endif
  );


  sqlite3_free(zTest);
  sqlite3_free(zTest2);


  return rc;
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

const char *sqlite3Fts3NextToken(const char *zStr, int *pn){
  const char *z1;
  const char *z2 = 0;

  /* Find the start of the next token. */
  z1 = zStr;
  while( z2==0 ){
    char c = *z1;
    switch( c ){
      case '\0': return 0;        /* No more tokens here */
      case '\'':
      case '"':
      case '`': {
        z2 = z1;
        while( *++z2 && (*z2!=c || *++z2==c) );

        break;
      }
      case '[':
        z2 = &z1[1];
        while( *z2 && z2[0]!=']' ) z2++;
        if( *z2 ) z2++;
        break;
................................................................................
  sqlite3 *db, 
  Fts3Hash *pHash, 
  const char *zName
){
  int rc = SQLITE_OK;
  void *p = (void *)pHash;
  const int any = SQLITE_ANY;



#ifdef SQLITE_TEST
  char *zTest = 0;
  char *zTest2 = 0;
  void *pdb = (void *)db;
  zTest = sqlite3_mprintf("%s_test", zName);
  zTest2 = sqlite3_mprintf("%s_internal_test", zName);
  if( !zTest || !zTest2 ){
    rc = SQLITE_NOMEM;
  }
#endif
................................................................................
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zName, 1, any, p, scalarFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zName, 2, any, p, scalarFunc, 0, 0))
#ifdef SQLITE_TEST
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest, 2, any, p, testFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest, 3, any, p, testFunc, 0, 0))
   || SQLITE_OK!=(rc = sqlite3_create_function(db, zTest2, 0, any, pdb, intTestFunc, 0, 0))
#endif
   );

#ifdef SQLITE_TEST
  sqlite3_free(zTest);
  sqlite3_free(zTest2);
#endif

  return rc;
}

#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */

typedef struct PendingList PendingList;
typedef struct SegmentNode SegmentNode;
typedef struct SegmentWriter SegmentWriter;

/*
** Data structure used while accumulating terms in the pending-terms hash
** table. The hash table entry maps from term (a string) to a malloced
** instance of this structure.
*/
struct PendingList {
  int nData;
  char *aData;
  int nSpace;
  sqlite3_int64 iLastDocid;
................................................................................
** this structure are only manipulated by code in this file, opaque handles
** of type Fts3SegReader* are also used by code in fts3.c to iterate through
** terms when querying the full-text index. See functions:
**
**   sqlite3Fts3SegReaderNew()
**   sqlite3Fts3SegReaderFree()
**   sqlite3Fts3SegReaderIterate()






*/
struct Fts3SegReader {
  int iIdx;                       /* Index within level */
  sqlite3_int64 iStartBlock;
  sqlite3_int64 iEndBlock;
  sqlite3_stmt *pStmt;            /* SQL Statement to access leaf nodes */
  char *aNode;                    /* Pointer to node data (or NULL) */
  int nNode;                      /* Size of buffer at aNode (or 0) */
  int nTermAlloc;                 /* Allocated size of zTerm buffer */


  /* Variables set by fts3SegReaderNext(). These may be read directly
  ** by the caller. They are valid from the time SegmentReaderNew() returns
  ** until SegmentReaderNext() returns something other than SQLITE_OK
  ** (i.e. SQLITE_DONE).
  */
  int nTerm;                      /* Number of bytes in current term */
................................................................................
  char *aDoclist;                 /* Pointer to doclist of current entry */
  int nDoclist;                   /* Size of doclist in current entry */

  /* The following variables are used to iterate through the current doclist */
  char *pOffsetList;
  sqlite3_int64 iDocid;
};



/*
** An instance of this structure is used to create a segment b-tree in the
** database. The internal details of this type are only accessed by the
** following functions:
**
**   fts3SegWriterAdd()
................................................................................
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_reset(pStmt);

  if( pzBlock ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    rc = sqlite3_step(pStmt); 
    if( rc!=SQLITE_ROW ){
      return SQLITE_CORRUPT;
    }
  
    *pnBlock = sqlite3_column_bytes(pStmt, 0);
    *pzBlock = (char *)sqlite3_column_blob(pStmt, 0);
    if( !*pzBlock ){
      return SQLITE_NOMEM;
    }
  }
  return SQLITE_OK;
}

/*
** Set *ppStmt to a statement handle that may be used to iterate through
................................................................................
static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){
  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */
  if( iDocid<=p->iPrevDocid || p->nPendingData>FTS3_MAX_PENDING_DATA ){
    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  return SQLITE_OK;
}

................................................................................
    pNext = pReader->aNode;
  }else{
    pNext = &pReader->aDoclist[pReader->nDoclist];
  }

  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){
    int rc;















    if( !pReader->pStmt ){
      pReader->aNode = 0;
      return SQLITE_OK;
    }
    rc = sqlite3_step(pReader->pStmt);
    if( rc!=SQLITE_ROW ){
      pReader->aNode = 0;
................................................................................
      /* Move the leaf-range SELECT statement to the aLeavesStmt[] array,
      ** so that it can be reused when required by another query.
      */
      assert( p->nLeavesStmt<p->nLeavesTotal );
      sqlite3_reset(pReader->pStmt);
      p->aLeavesStmt[p->nLeavesStmt++] = pReader->pStmt;
    }

    sqlite3_free(pReader->zTerm);

    sqlite3_free(pReader);
  }
}

/*
** Allocate a new SegReader object.
*/
................................................................................
    *ppReader = pReader;
  }else{
    sqlite3Fts3SegReaderFree(p, pReader);
  }
  return rc;
}



































































































/*
** The second argument to this function is expected to be a statement of
** the form:
**
**   SELECT 
**     idx,                  -- col 0
................................................................................

/*
** Compare the entries pointed to by two Fts3SegReader structures. 
** Comparison is as follows:
**
**   1) EOF is greater than not EOF.
**
**   2) The current terms (if any) are compared with memcmp(). If one
**      term is a prefix of another, the longer term is considered the
**      larger.
**
**   3) By segment age. An older segment is considered larger.
*/
static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){
  int rc;
................................................................................
  char *z,                        /* Pointer to buffer containing block data */
  int n                           /* Size of buffer z in bytes */
){
  sqlite3_stmt *pStmt;
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    rc = sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);
    if( rc==SQLITE_OK ){
      sqlite3_step(pStmt);
      rc = sqlite3_reset(pStmt);
    }
  }
  return rc;
}

/* 
** Insert a record into the %_segdir table.
*/
................................................................................
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pStmt, 1, iLevel);
    sqlite3_bind_int(pStmt, 2, iIdx);
    sqlite3_bind_int64(pStmt, 3, iStartBlock);
    sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);
    sqlite3_bind_int64(pStmt, 5, iEndBlock);
    rc = sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
    if( rc==SQLITE_OK ){
      sqlite3_step(pStmt);
      rc = sqlite3_reset(pStmt);
    }
  }
  return rc;
}

/*
** Return the size of the common prefix (if any) shared by zPrev and
** zNext, in bytes. For example, 
................................................................................
}

/*
** sqlite3Fts3SegReaderIterate() callback used when merging multiple 
** segments to create a single, larger segment.
*/
static int fts3MergeCallback(
  Fts3Table *p,
  void *pContext,
  char *zTerm,
  int nTerm,
  char *aDoclist,
  int nDoclist
){
  SegmentWriter **ppW = (SegmentWriter **)pContext;
  return fts3SegWriterAdd(p, ppW, 1, zTerm, nTerm, aDoclist, nDoclist);
}

















/*
** This function is used to iterate through a contiguous set of terms 
** stored in the full-text index. It merges data contained in one or 
** more segments to support this.
**
** The second argument is passed an array of pointers to SegReader objects
................................................................................
  if( pFilter->zTerm ){
    int nTerm = pFilter->nTerm;
    const char *zTerm = pFilter->zTerm;
    for(i=0; i<nSegment; i++){
      Fts3SegReader *pSeg = apSegment[i];
      while( fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 ){
        rc = fts3SegReaderNext(pSeg);
        if( rc!=SQLITE_OK ) goto finished;
      }
    }
  }

  fts3SegReaderSort(apSegment, nSegment, nSegment, fts3SegReaderCmp);
  while( apSegment[0]->aNode ){
    int nTerm = apSegment[0]->nTerm;
    char *zTerm = apSegment[0]->zTerm;
................................................................................
        && apSegment[nMerge]->aNode
        && apSegment[nMerge]->nTerm==nTerm 
        && 0==memcmp(zTerm, apSegment[nMerge]->zTerm, nTerm)
    ){
      nMerge++;
    }


    if( nMerge==1 && !isIgnoreEmpty && !isColFilter && isRequirePos ){
      Fts3SegReader *p0 = apSegment[0];
      rc = xFunc(p, pContext, zTerm, nTerm, p0->aDoclist, p0->nDoclist);
      if( rc!=SQLITE_OK ) goto finished;
    }else{
      int nDoclist = 0;           /* Size of doclist */
      sqlite3_int64 iPrev = 0;    /* Previous docid stored in doclist */

................................................................................
        int j;                    /* Number of segments that share a docid */
        char *pList;
        int nList;
        int nByte;
        sqlite3_int64 iDocid = apSegment[0]->iDocid;
        fts3SegReaderNextDocid(apSegment[0], &pList, &nList);
        j = 1;
        while( j<nMerge 
            && apSegment[j]->pOffsetList 
            && apSegment[j]->iDocid==iDocid 
        ){
          fts3SegReaderNextDocid(apSegment[j], 0, 0);
          j++;
        }

        if( isColFilter ){
          fts3ColumnFilter(pFilter->iCol, &pList, &nList);
................................................................................
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(Fts3Table *p, int iLevel){
  int i;                          /* Iterator variable */
  int rc;                         /* Return code */
  int iIdx;                       /* Index of new segment */
  int iNewLevel;                  /* Level to create new segment at */
  sqlite3_stmt *pStmt;
  SegmentWriter *pWriter = 0;
  int nSegment = 0;               /* Number of segments being merged */
  Fts3SegReader **apSegment = 0;  /* Array of Segment iterators */

  Fts3SegFilter filter;           /* Segment term filter condition */

  if( iLevel<0 ){
    /* This call is to merge all segments in the database to a single
    ** segment. The level of the new segment is equal to the the numerically 
    ** greatest segment level currently present in the database. The index
    ** of the new segment is always 0.
    */
    iIdx = 0;


    rc = fts3SegmentCountMax(p, &nSegment, &iNewLevel);


    if( nSegment==1 ){
      return SQLITE_DONE;
    }
  }else{
    /* This call is to merge all segments at level iLevel. Find the next
    ** available segment index at level iLevel+1. The call to
    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
    ** a single iLevel+2 segment if necessary.
    */
    iNewLevel = iLevel+1;
    rc = fts3AllocateSegdirIdx(p, iNewLevel, &iIdx);
    if( rc!=SQLITE_OK ) return rc;
    rc = fts3SegmentCount(p, iLevel, &nSegment);

  }
  if( rc!=SQLITE_OK ) return rc;
  assert( nSegment>0 );
  assert( iNewLevel>=0 );

  /* Allocate space for an array of pointers to segment iterators. */
  apSegment = (Fts3SegReader**)sqlite3_malloc(sizeof(Fts3SegReader *)*nSegment);
  if( !apSegment ){
    return SQLITE_NOMEM;

  }
  memset(apSegment, 0, sizeof(Fts3SegReader *)*nSegment);

  /* Allocate a Fts3SegReader structure for each segment being merged. A 
  ** Fts3SegReader stores the state data required to iterate through all 
  ** entries on all leaves of a single segment. 
  */
................................................................................
  for(i=0; SQLITE_ROW==(sqlite3_step(pStmt)); i++){
    rc = fts3SegReaderNew(p, pStmt, i, &apSegment[i]);
    if( rc!=SQLITE_OK ){
      goto finished;
    }
  }
  rc = sqlite3_reset(pStmt);




  pStmt = 0;
  if( rc!=SQLITE_OK ) goto finished;

  memset(&filter, 0, sizeof(Fts3SegFilter));
  filter.flags = FTS3_SEGMENT_REQUIRE_POS;
  filter.flags |= (iLevel<0 ? FTS3_SEGMENT_IGNORE_EMPTY : 0);
  rc = sqlite3Fts3SegReaderIterate(p, apSegment, nSegment,
................................................................................
  fts3SegWriterFree(pWriter);
  if( apSegment ){
    for(i=0; i<nSegment; i++){
      sqlite3Fts3SegReaderFree(p, apSegment[i]);
    }
    sqlite3_free(apSegment);
  }

  sqlite3_reset(pStmt);
  return rc;
}

/*
** This is a comparison function used as a qsort() callback when sorting
** an array of pending terms by term. This occurs as part of flushing
** the contents of the pending-terms hash table to the database.
*/
static int qsortCompare(const void *lhs, const void *rhs){
  char *z1 = fts3HashKey(*(Fts3HashElem **)lhs);
  char *z2 = fts3HashKey(*(Fts3HashElem **)rhs);
  int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs);
  int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs);

  int n = (n1<n2 ? n1 : n2);
  int c = memcmp(z1, z2, n);
  if( c==0 ){
    c = n1 - n2;
  }
  return c;
}


/* 
** Flush the contents of pendingTerms to a level 0 segment.
*/
int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
  Fts3HashElem *pElem;
  int idx, rc, i;
  Fts3HashElem **apElem;          /* Array of pointers to hash elements */
  int nElem;                      /* Number of terms in new segment */

  SegmentWriter *pWriter = 0;     /* Used to write the segment */



  /* Find the number of terms that will make up the new segment. If there
  ** are no terms, return early (do not bother to write an empty segment).
  */
  nElem = fts3HashCount(&p->pendingTerms);
  if( nElem==0 ){
    assert( p->nPendingData==0 );
    return SQLITE_OK;
  }

  /* Determine the next index at level 0, merging as necessary. */



  rc = fts3AllocateSegdirIdx(p, 0, &idx);
  if( rc!=SQLITE_OK ){
    return rc;
  } 


  apElem = sqlite3_malloc(nElem*sizeof(Fts3HashElem *));
  if( !apElem ){
    return SQLITE_NOMEM;
  }

  i = 0;
  for(pElem=fts3HashFirst(&p->pendingTerms); pElem; pElem=fts3HashNext(pElem)){
    apElem[i++] = pElem;
  }
  assert( i==nElem );

  /* TODO(shess) Should we allow user-defined collation sequences,
  ** here?  I think we only need that once we support prefix searches.
  ** Also, should we be using qsort()?
  */
  if( nElem>1 ){
    qsort(apElem, nElem, sizeof(Fts3HashElem *), qsortCompare);



  }






  /* Write the segment tree into the database. */
  for(i=0; rc==SQLITE_OK && i<nElem; i++){
    const char *z = fts3HashKey(apElem[i]);
    int n = fts3HashKeysize(apElem[i]);
    PendingList *pList = fts3HashData(apElem[i]);
    rc = fts3SegWriterAdd(p, &pWriter, 0, z, n, pList->aData, pList->nData+1);
  }




  if( rc==SQLITE_OK ){
    rc = fts3SegWriterFlush(p, pWriter, 0, idx);
  }

  /* Free all allocated resources before returning */
  fts3SegWriterFree(pWriter);


  sqlite3_free(apElem);
  sqlite3Fts3PendingTermsClear(p);





































  return rc;
}

/*
** This function does the work for the xUpdate method of FTS3 virtual
** tables.
*/
................................................................................
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  sqlite3_int64 iRemove = 0;      /* Rowid removed by UPDATE or DELETE */


  /* If this is a DELETE or UPDATE operation, remove the old record. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    int isEmpty;
    rc = fts3IsEmpty(p, apVal, &isEmpty);
    if( rc==SQLITE_OK ){
      if( isEmpty ){
................................................................................
          rc = fts3DeleteTerms(p, apVal);
          if( rc==SQLITE_OK ){
            rc = fts3SqlExec(p, SQL_DELETE_CONTENT, apVal);
          }
        }
      }
    }


  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    rc = fts3InsertData(p, apVal, pRowid);
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=iRemove) ){
      rc = fts3PendingTermsDocid(p, *pRowid);
................................................................................
** merge all segments in the database (including the new segment, if 
** there was any data to flush) into a single segment. 
*/
int sqlite3Fts3Optimize(Fts3Table *p){
  int rc;
  rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc==SQLITE_OK ){
      rc = fts3SegmentMerge(p, -1);
    }
    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);



    }else{
      sqlite3_exec(p->db, "ROLLBACK TO fts3 ; RELEASE fts3", 0, 0, 0);

    }
  }
  return rc;
}

#endif

typedef struct PendingList PendingList;
typedef struct SegmentNode SegmentNode;
typedef struct SegmentWriter SegmentWriter;

/*
** Data structure used while accumulating terms in the pending-terms hash
** table. The hash table entry maps from term (a string) to a malloc'd
** instance of this structure.
*/
struct PendingList {
  int nData;
  char *aData;
  int nSpace;
  sqlite3_int64 iLastDocid;
................................................................................
** this structure are only manipulated by code in this file, opaque handles
** of type Fts3SegReader* are also used by code in fts3.c to iterate through
** terms when querying the full-text index. See functions:
**
**   sqlite3Fts3SegReaderNew()
**   sqlite3Fts3SegReaderFree()
**   sqlite3Fts3SegReaderIterate()
**
** Methods used to manipulate Fts3SegReader structures:
**
**   fts3SegReaderNext()
**   fts3SegReaderFirstDocid()
**   fts3SegReaderNextDocid()
*/
struct Fts3SegReader {
  int iIdx;                       /* Index within level, or 0x7FFFFFFF for PT */
  sqlite3_int64 iStartBlock;
  sqlite3_int64 iEndBlock;
  sqlite3_stmt *pStmt;            /* SQL Statement to access leaf nodes */
  char *aNode;                    /* Pointer to node data (or NULL) */
  int nNode;                      /* Size of buffer at aNode (or 0) */
  int nTermAlloc;                 /* Allocated size of zTerm buffer */
  Fts3HashElem **ppNextElem;

  /* Variables set by fts3SegReaderNext(). These may be read directly
  ** by the caller. They are valid from the time SegmentReaderNew() returns
  ** until SegmentReaderNext() returns something other than SQLITE_OK
  ** (i.e. SQLITE_DONE).
  */
  int nTerm;                      /* Number of bytes in current term */
................................................................................
  char *aDoclist;                 /* Pointer to doclist of current entry */
  int nDoclist;                   /* Size of doclist in current entry */

  /* The following variables are used to iterate through the current doclist */
  char *pOffsetList;
  sqlite3_int64 iDocid;
};

#define fts3SegReaderIsPending(p) ((p)->ppNextElem!=0)

/*
** An instance of this structure is used to create a segment b-tree in the
** database. The internal details of this type are only accessed by the
** following functions:
**
**   fts3SegWriterAdd()
................................................................................
  if( rc!=SQLITE_OK ) return rc;
  sqlite3_reset(pStmt);

  if( pzBlock ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    rc = sqlite3_step(pStmt); 
    if( rc!=SQLITE_ROW ){
      return (rc==SQLITE_DONE ? SQLITE_CORRUPT : rc);
    }
  
    *pnBlock = sqlite3_column_bytes(pStmt, 0);
    *pzBlock = (char *)sqlite3_column_blob(pStmt, 0);
    if( sqlite3_column_type(pStmt, 0)!=SQLITE_BLOB ){
      return SQLITE_CORRUPT;
    }
  }
  return SQLITE_OK;
}

/*
** Set *ppStmt to a statement handle that may be used to iterate through
................................................................................
static int fts3PendingTermsDocid(Fts3Table *p, sqlite_int64 iDocid){
  /* TODO(shess) Explore whether partially flushing the buffer on
  ** forced-flush would provide better performance.  I suspect that if
  ** we ordered the doclists by size and flushed the largest until the
  ** buffer was half empty, that would let the less frequent terms
  ** generate longer doclists.
  */
  if( iDocid<=p->iPrevDocid || p->nPendingData>p->nMaxPendingData ){
    int rc = sqlite3Fts3PendingTermsFlush(p);
    if( rc!=SQLITE_OK ) return rc;
  }
  p->iPrevDocid = iDocid;
  return SQLITE_OK;
}

................................................................................
    pNext = pReader->aNode;
  }else{
    pNext = &pReader->aDoclist[pReader->nDoclist];
  }

  if( !pNext || pNext>=&pReader->aNode[pReader->nNode] ){
    int rc;
    if( fts3SegReaderIsPending(pReader) ){
      Fts3HashElem *pElem = *(pReader->ppNextElem);
      if( pElem==0 ){
        pReader->aNode = 0;
      }else{
        PendingList *pList = (PendingList *)fts3HashData(pElem);
        pReader->zTerm = (char *)fts3HashKey(pElem);
        pReader->nTerm = fts3HashKeysize(pElem);
        pReader->nNode = pReader->nDoclist = pList->nData + 1;
        pReader->aNode = pReader->aDoclist = pList->aData;
        pReader->ppNextElem++;
        assert( pReader->aNode );
      }
      return SQLITE_OK;
    }
    if( !pReader->pStmt ){
      pReader->aNode = 0;
      return SQLITE_OK;
    }
    rc = sqlite3_step(pReader->pStmt);
    if( rc!=SQLITE_ROW ){
      pReader->aNode = 0;
................................................................................
      /* Move the leaf-range SELECT statement to the aLeavesStmt[] array,
      ** so that it can be reused when required by another query.
      */
      assert( p->nLeavesStmt<p->nLeavesTotal );
      sqlite3_reset(pReader->pStmt);
      p->aLeavesStmt[p->nLeavesStmt++] = pReader->pStmt;
    }
    if( !fts3SegReaderIsPending(pReader) ){
      sqlite3_free(pReader->zTerm);
    }
    sqlite3_free(pReader);
  }
}

/*
** Allocate a new SegReader object.
*/
................................................................................
    *ppReader = pReader;
  }else{
    sqlite3Fts3SegReaderFree(p, pReader);
  }
  return rc;
}

/*
** This is a comparison function used as a qsort() callback when sorting
** an array of pending terms by term. This occurs as part of flushing
** the contents of the pending-terms hash table to the database.
*/
static int fts3CompareElemByTerm(const void *lhs, const void *rhs){
  char *z1 = fts3HashKey(*(Fts3HashElem **)lhs);
  char *z2 = fts3HashKey(*(Fts3HashElem **)rhs);
  int n1 = fts3HashKeysize(*(Fts3HashElem **)lhs);
  int n2 = fts3HashKeysize(*(Fts3HashElem **)rhs);

  int n = (n1<n2 ? n1 : n2);
  int c = memcmp(z1, z2, n);
  if( c==0 ){
    c = n1 - n2;
  }
  return c;
}

/*
** This function is used to allocate an Fts3SegReader that iterates through
** a subset of the terms stored in the Fts3Table.pendingTerms array.
*/
int sqlite3Fts3SegReaderPending(
  Fts3Table *p,                   /* Virtual table handle */
  const char *zTerm,              /* Term to search for */
  int nTerm,                      /* Size of buffer zTerm */
  int isPrefix,                   /* True for a term-prefix query */
  Fts3SegReader **ppReader        /* OUT: SegReader for pending-terms */
){
  Fts3SegReader *pReader = 0;     /* Fts3SegReader object to return */
  Fts3HashElem **aElem = 0;       /* Array of term hash entries to scan */
  int nElem = 0;                  /* Size of array at aElem */
  int rc = SQLITE_OK;             /* Return Code */

  if( isPrefix ){
    int nAlloc = 0;               /* Size of allocated array at aElem */
    Fts3HashElem *pE = 0;         /* Iterator variable */

    for(pE=fts3HashFirst(&p->pendingTerms); pE; pE=fts3HashNext(pE)){
      char *zKey = (char *)fts3HashKey(pE);
      int nKey = fts3HashKeysize(pE);
      if( nTerm==0 || (nKey>=nTerm && 0==memcmp(zKey, zTerm, nTerm)) ){
        if( nElem==nAlloc ){
          Fts3HashElem **aElem2;
          nAlloc += 16;
          aElem2 = (Fts3HashElem **)sqlite3_realloc(
              aElem, nAlloc*sizeof(Fts3HashElem *)
          );
          if( !aElem2 ){
            rc = SQLITE_NOMEM;
            nElem = 0;
            break;
          }
          aElem = aElem2;
        }
        aElem[nElem++] = pE;
      }
    }

    /* If more than one term matches the prefix, sort the Fts3HashElem
    ** objects in term order using qsort(). This uses the same comparison
    ** callback as is used when flushing terms to disk.
    */
    if( nElem>1 ){
      qsort(aElem, nElem, sizeof(Fts3HashElem *), fts3CompareElemByTerm);
    }

  }else{
    Fts3HashElem *pE = fts3HashFindElem(&p->pendingTerms, zTerm, nTerm);
    if( pE ){
      aElem = &pE;
      nElem = 1;
    }
  }

  if( nElem>0 ){
    int nByte = sizeof(Fts3SegReader) + (nElem+1)*sizeof(Fts3HashElem *);
    pReader = (Fts3SegReader *)sqlite3_malloc(nByte);
    if( !pReader ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pReader, 0, nByte);
      pReader->iIdx = 0x7FFFFFFF;
      pReader->ppNextElem = (Fts3HashElem **)&pReader[1];
      memcpy(pReader->ppNextElem, aElem, nElem*sizeof(Fts3HashElem *));
      fts3SegReaderNext(pReader);
    }
  }

  if( isPrefix ){
    sqlite3_free(aElem);
  }
  *ppReader = pReader;
  return rc;
}


/*
** The second argument to this function is expected to be a statement of
** the form:
**
**   SELECT 
**     idx,                  -- col 0
................................................................................

/*
** Compare the entries pointed to by two Fts3SegReader structures. 
** Comparison is as follows:
**
**   1) EOF is greater than not EOF.
**
**   2) The current terms (if any) are compared using memcmp(). If one
**      term is a prefix of another, the longer term is considered the
**      larger.
**
**   3) By segment age. An older segment is considered larger.
*/
static int fts3SegReaderCmp(Fts3SegReader *pLhs, Fts3SegReader *pRhs){
  int rc;
................................................................................
  char *z,                        /* Pointer to buffer containing block data */
  int n                           /* Size of buffer z in bytes */
){
  sqlite3_stmt *pStmt;
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGMENTS, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int64(pStmt, 1, iBlock);
    sqlite3_bind_blob(pStmt, 2, z, n, SQLITE_STATIC);

    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);

  }
  return rc;
}

/* 
** Insert a record into the %_segdir table.
*/
................................................................................
  int rc = fts3SqlStmt(p, SQL_INSERT_SEGDIR, &pStmt, 0);
  if( rc==SQLITE_OK ){
    sqlite3_bind_int(pStmt, 1, iLevel);
    sqlite3_bind_int(pStmt, 2, iIdx);
    sqlite3_bind_int64(pStmt, 3, iStartBlock);
    sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);
    sqlite3_bind_int64(pStmt, 5, iEndBlock);
    sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);

    sqlite3_step(pStmt);
    rc = sqlite3_reset(pStmt);

  }
  return rc;
}

/*
** Return the size of the common prefix (if any) shared by zPrev and
** zNext, in bytes. For example, 
................................................................................
}

/*
** sqlite3Fts3SegReaderIterate() callback used when merging multiple 
** segments to create a single, larger segment.
*/
static int fts3MergeCallback(
  Fts3Table *p,                   /* FTS3 Virtual table handle */
  void *pContext,                 /* Pointer to SegmentWriter* to write with */
  char *zTerm,                    /* Term to write to the db */
  int nTerm,                      /* Number of bytes in zTerm */
  char *aDoclist,                 /* Doclist associated with zTerm */
  int nDoclist                    /* Number of bytes in doclist */
){
  SegmentWriter **ppW = (SegmentWriter **)pContext;
  return fts3SegWriterAdd(p, ppW, 1, zTerm, nTerm, aDoclist, nDoclist);
}

/*
** sqlite3Fts3SegReaderIterate() callback used when flushing the contents
** of the pending-terms hash table to the database.
*/
static int fts3FlushCallback(
  Fts3Table *p,                   /* FTS3 Virtual table handle */
  void *pContext,                 /* Pointer to SegmentWriter* to write with */
  char *zTerm,                    /* Term to write to the db */
  int nTerm,                      /* Number of bytes in zTerm */
  char *aDoclist,                 /* Doclist associated with zTerm */
  int nDoclist                    /* Number of bytes in doclist */
){
  SegmentWriter **ppW = (SegmentWriter **)pContext;
  return fts3SegWriterAdd(p, ppW, 0, zTerm, nTerm, aDoclist, nDoclist);
}

/*
** This function is used to iterate through a contiguous set of terms 
** stored in the full-text index. It merges data contained in one or 
** more segments to support this.
**
** The second argument is passed an array of pointers to SegReader objects
................................................................................
  if( pFilter->zTerm ){
    int nTerm = pFilter->nTerm;
    const char *zTerm = pFilter->zTerm;
    for(i=0; i<nSegment; i++){
      Fts3SegReader *pSeg = apSegment[i];
      while( fts3SegReaderTermCmp(pSeg, zTerm, nTerm)<0 ){
        rc = fts3SegReaderNext(pSeg);
        if( rc!=SQLITE_OK ) goto finished; }

    }
  }

  fts3SegReaderSort(apSegment, nSegment, nSegment, fts3SegReaderCmp);
  while( apSegment[0]->aNode ){
    int nTerm = apSegment[0]->nTerm;
    char *zTerm = apSegment[0]->zTerm;
................................................................................
        && apSegment[nMerge]->aNode
        && apSegment[nMerge]->nTerm==nTerm 
        && 0==memcmp(zTerm, apSegment[nMerge]->zTerm, nTerm)
    ){
      nMerge++;
    }

    assert( isIgnoreEmpty || (isRequirePos && !isColFilter) );
    if( nMerge==1 && !isIgnoreEmpty ){
      Fts3SegReader *p0 = apSegment[0];
      rc = xFunc(p, pContext, zTerm, nTerm, p0->aDoclist, p0->nDoclist);
      if( rc!=SQLITE_OK ) goto finished;
    }else{
      int nDoclist = 0;           /* Size of doclist */
      sqlite3_int64 iPrev = 0;    /* Previous docid stored in doclist */

................................................................................
        int j;                    /* Number of segments that share a docid */
        char *pList;
        int nList;
        int nByte;
        sqlite3_int64 iDocid = apSegment[0]->iDocid;
        fts3SegReaderNextDocid(apSegment[0], &pList, &nList);
        j = 1;
        while( j<nMerge
            && apSegment[j]->pOffsetList
            && apSegment[j]->iDocid==iDocid
        ){
          fts3SegReaderNextDocid(apSegment[j], 0, 0);
          j++;
        }

        if( isColFilter ){
          fts3ColumnFilter(pFilter->iCol, &pList, &nList);
................................................................................
** an SQLite error code is returned.
*/
static int fts3SegmentMerge(Fts3Table *p, int iLevel){
  int i;                          /* Iterator variable */
  int rc;                         /* Return code */
  int iIdx;                       /* Index of new segment */
  int iNewLevel;                  /* Level to create new segment at */
  sqlite3_stmt *pStmt = 0;
  SegmentWriter *pWriter = 0;
  int nSegment = 0;               /* Number of segments being merged */
  Fts3SegReader **apSegment = 0;  /* Array of Segment iterators */
  Fts3SegReader *pPending = 0;    /* Iterator for pending-terms */
  Fts3SegFilter filter;           /* Segment term filter condition */

  if( iLevel<0 ){
    /* This call is to merge all segments in the database to a single
    ** segment. The level of the new segment is equal to the the numerically 
    ** greatest segment level currently present in the database. The index
    ** of the new segment is always 0.
    */
    iIdx = 0;
    rc = sqlite3Fts3SegReaderPending(p, 0, 0, 1, &pPending);
    if( rc!=SQLITE_OK ) goto finished;
    rc = fts3SegmentCountMax(p, &nSegment, &iNewLevel);
    if( rc!=SQLITE_OK ) goto finished;
    nSegment += (pPending!=0);
    if( nSegment<=1 ){
      return SQLITE_DONE;
    }
  }else{
    /* This call is to merge all segments at level iLevel. Find the next
    ** available segment index at level iLevel+1. The call to
    ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
    ** a single iLevel+2 segment if necessary.
    */
    iNewLevel = iLevel+1;
    rc = fts3AllocateSegdirIdx(p, iNewLevel, &iIdx);
    if( rc!=SQLITE_OK ) goto finished;
    rc = fts3SegmentCount(p, iLevel, &nSegment);
    if( rc!=SQLITE_OK ) goto finished;
  }

  assert( nSegment>0 );
  assert( iNewLevel>=0 );

  /* Allocate space for an array of pointers to segment iterators. */
  apSegment = (Fts3SegReader**)sqlite3_malloc(sizeof(Fts3SegReader *)*nSegment);
  if( !apSegment ){
    rc = SQLITE_NOMEM;
    goto finished;
  }
  memset(apSegment, 0, sizeof(Fts3SegReader *)*nSegment);

  /* Allocate a Fts3SegReader structure for each segment being merged. A 
  ** Fts3SegReader stores the state data required to iterate through all 
  ** entries on all leaves of a single segment. 
  */
................................................................................
  for(i=0; SQLITE_ROW==(sqlite3_step(pStmt)); i++){
    rc = fts3SegReaderNew(p, pStmt, i, &apSegment[i]);
    if( rc!=SQLITE_OK ){
      goto finished;
    }
  }
  rc = sqlite3_reset(pStmt);
  if( pPending ){
    apSegment[i] = pPending;
    pPending = 0;
  }
  pStmt = 0;
  if( rc!=SQLITE_OK ) goto finished;

  memset(&filter, 0, sizeof(Fts3SegFilter));
  filter.flags = FTS3_SEGMENT_REQUIRE_POS;
  filter.flags |= (iLevel<0 ? FTS3_SEGMENT_IGNORE_EMPTY : 0);
  rc = sqlite3Fts3SegReaderIterate(p, apSegment, nSegment,
................................................................................
  fts3SegWriterFree(pWriter);
  if( apSegment ){
    for(i=0; i<nSegment; i++){
      sqlite3Fts3SegReaderFree(p, apSegment[i]);
    }
    sqlite3_free(apSegment);
  }
  sqlite3Fts3SegReaderFree(p, pPending);
  sqlite3_reset(pStmt);
  return rc;
}





















/* 
** Flush the contents of pendingTerms to a level 0 segment.
*/
int sqlite3Fts3PendingTermsFlush(Fts3Table *p){



  int rc;                         /* Return Code */
  int idx;                        /* Index of new segment created */
  SegmentWriter *pWriter = 0;     /* Used to write the segment */
  Fts3SegReader *pReader = 0;     /* Used to iterate through the hash table */

  /* Allocate a SegReader object to iterate through the contents of the
  ** pending-terms table. If an error occurs, or if there are no terms
  ** in the pending-terms table, return immediately.
  */
  rc = sqlite3Fts3SegReaderPending(p, 0, 0, 1, &pReader);
  if( rc!=SQLITE_OK || pReader==0 ){

    return rc;
  }

  /* Determine the next index at level 0. If level 0 is already full, this
  ** call may merge all existing level 0 segments into a single level 1
  ** segment.
  */
  rc = fts3AllocateSegdirIdx(p, 0, &idx);




  /* If no errors have occured, iterate through the contents of the 
  ** pending-terms hash table using the Fts3SegReader iterator. The callback
  ** writes each term (along with its doclist) to the database via the
  ** SegmentWriter handle pWriter.











  */


  if( rc==SQLITE_OK ){
    void *c = (void *)&pWriter;   /* SegReaderIterate() callback context */
    Fts3SegFilter f;              /* SegReaderIterate() parameters */

    memset(&f, 0, sizeof(Fts3SegFilter));
    f.flags = FTS3_SEGMENT_REQUIRE_POS;
    rc = sqlite3Fts3SegReaderIterate(p, &pReader, 1, &f, fts3FlushCallback, c);
  }
  assert( pWriter || rc!=SQLITE_OK );








  /* If no errors have occured, flush the SegmentWriter object to the
  ** database. Then delete the SegmentWriter and Fts3SegReader objects
  ** allocated by this function.
  */
  if( rc==SQLITE_OK ){
    rc = fts3SegWriterFlush(p, pWriter, 0, idx);
  }


  fts3SegWriterFree(pWriter);
  sqlite3Fts3SegReaderFree(p, pReader);

  if( rc==SQLITE_OK ){
    sqlite3Fts3PendingTermsClear(p);
  }
  return rc;
}

/*
** Handle a 'special' INSERT of the form:
**
**   "INSERT INTO tbl(tbl) VALUES(<expr>)"
**
** Argument pVal contains the result of <expr>. Currently the only 
** meaningful value to insert is the text 'optimize'.
*/
static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
  int rc;                         /* Return Code */
  const char *zVal = (const char *)sqlite3_value_text(pVal);
  int nVal = sqlite3_value_bytes(pVal);

  if( !zVal ){
    return SQLITE_NOMEM;
  }else if( nVal==8 && 0==sqlite3_strnicmp(zVal, "optimize", 8) ){
    rc = fts3SegmentMerge(p, -1);
    if( rc==SQLITE_DONE || rc==SQLITE_OK ){
      rc = SQLITE_OK;
      sqlite3Fts3PendingTermsClear(p);
    }
#ifdef SQLITE_TEST
  }else if( nVal>9 && 0==sqlite3_strnicmp(zVal, "nodesize=", 9) ){
    p->nNodeSize = atoi(&zVal[9]);
    rc = SQLITE_OK;
  }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
    p->nMaxPendingData = atoi(&zVal[11]);
    rc = SQLITE_OK;
#endif
  }else{
    rc = SQLITE_ERROR;
  }

  return rc;
}

/*
** This function does the work for the xUpdate method of FTS3 virtual
** tables.
*/
................................................................................
  sqlite3_value **apVal,          /* Array of arguments */
  sqlite_int64 *pRowid            /* OUT: The affected (or effected) rowid */
){
  Fts3Table *p = (Fts3Table *)pVtab;
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  sqlite3_int64 iRemove = 0;      /* Rowid removed by UPDATE or DELETE */


  /* If this is a DELETE or UPDATE operation, remove the old record. */
  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
    int isEmpty;
    rc = fts3IsEmpty(p, apVal, &isEmpty);
    if( rc==SQLITE_OK ){
      if( isEmpty ){
................................................................................
          rc = fts3DeleteTerms(p, apVal);
          if( rc==SQLITE_OK ){
            rc = fts3SqlExec(p, SQL_DELETE_CONTENT, apVal);
          }
        }
      }
    }
  }else if( sqlite3_value_type(apVal[p->nColumn+2])!=SQLITE_NULL ){
    return fts3SpecialInsert(p, apVal[p->nColumn+2]);
  }
  
  /* If this is an INSERT or UPDATE operation, insert the new record. */
  if( nArg>1 && rc==SQLITE_OK ){
    rc = fts3InsertData(p, apVal, pRowid);
    if( rc==SQLITE_OK && (!isRemove || *pRowid!=iRemove) ){
      rc = fts3PendingTermsDocid(p, *pRowid);
................................................................................
** merge all segments in the database (including the new segment, if 
** there was any data to flush) into a single segment. 
*/
int sqlite3Fts3Optimize(Fts3Table *p){
  int rc;
  rc = sqlite3_exec(p->db, "SAVEPOINT fts3", 0, 0, 0);
  if( rc==SQLITE_OK ){


    rc = fts3SegmentMerge(p, -1);

    if( rc==SQLITE_OK ){
      rc = sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
      if( rc==SQLITE_OK ){
        sqlite3Fts3PendingTermsClear(p);
      }
    }else{
      sqlite3_exec(p->db, "ROLLBACK TO fts3", 0, 0, 0);
      sqlite3_exec(p->db, "RELEASE fts3", 0, 0, 0);
    }
  }
  return rc;
}

#endif

  $(TOP)/src/os_os2.c $(TOP)/src/os_unix.c $(TOP)/src/os_win.c                 \
  $(TOP)/src/pager.c $(TOP)/src/pragma.c $(TOP)/src/prepare.c                  \
  $(TOP)/src/printf.c $(TOP)/src/random.c $(TOP)/src/pcache.c                  \
  $(TOP)/src/pcache1.c $(TOP)/src/select.c $(TOP)/src/tokenize.c               \
  $(TOP)/src/utf.c $(TOP)/src/util.c $(TOP)/src/vdbeapi.c $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c $(TOP)/src/vdbemem.c $(TOP)/src/where.c parse.c            \
  $(TOP)/ext/fts3/fts3.c $(TOP)/ext/fts3/fts3_expr.c                           \
  $(TOP)/ext/fts3/fts3_tokenizer.c                                             \
  $(TOP)/ext/async/sqlite3async.c

# Header files used by all library source files.
#
HDR = \
   $(TOP)/src/btree.h \
   $(TOP)/src/btreeInt.h \

  $(TOP)/src/os_os2.c $(TOP)/src/os_unix.c $(TOP)/src/os_win.c                 \
  $(TOP)/src/pager.c $(TOP)/src/pragma.c $(TOP)/src/prepare.c                  \
  $(TOP)/src/printf.c $(TOP)/src/random.c $(TOP)/src/pcache.c                  \
  $(TOP)/src/pcache1.c $(TOP)/src/select.c $(TOP)/src/tokenize.c               \
  $(TOP)/src/utf.c $(TOP)/src/util.c $(TOP)/src/vdbeapi.c $(TOP)/src/vdbeaux.c \
  $(TOP)/src/vdbe.c $(TOP)/src/vdbemem.c $(TOP)/src/where.c parse.c            \
  $(TOP)/ext/fts3/fts3.c $(TOP)/ext/fts3/fts3_expr.c                           \
  $(TOP)/ext/fts3/fts3_tokenizer.c $(TOP)/ext/fts3/fts3_write.c                \
  $(TOP)/ext/async/sqlite3async.c

# Header files used by all library source files.
#
HDR = \
   $(TOP)/src/btree.h \
   $(TOP)/src/btreeInt.h \

*/
void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
  Table *p;
  Db *pDb;

  assert( db!=0 );
  assert( iDb>=0 && iDb<db->nDb );
  assert( zTabName && zTabName[0] );

  pDb = &db->aDb[iDb];
  p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName,
                        sqlite3Strlen30(zTabName),0);
  sqlite3DeleteTable(p);
  db->flags |= SQLITE_InternChanges;
}

*/
void sqlite3UnlinkAndDeleteTable(sqlite3 *db, int iDb, const char *zTabName){
  Table *p;
  Db *pDb;

  assert( db!=0 );
  assert( iDb>=0 && iDb<db->nDb );
  assert( zTabName );
  testcase( zTabName[0]==0 );  /* Zero-length table names are allowed */
  pDb = &db->aDb[iDb];
  p = sqlite3HashInsert(&pDb->pSchema->tblHash, zTabName,
                        sqlite3Strlen30(zTabName),0);
  sqlite3DeleteTable(p);
  db->flags |= SQLITE_InternChanges;
}

      sqlite3_result_null(context);
      break;
    }
  }
}

/*
** Implementation of the abs() function



*/
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  assert( argc==1 );
  UNUSED_PARAMETER(argc);
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_INTEGER: {
      i64 iVal = sqlite3_value_int64(argv[0]);
      if( iVal<0 ){
        if( (iVal<<1)==0 ){



          sqlite3_result_error(context, "integer overflow", -1);
          return;
        }
        iVal = -iVal;
      } 
      sqlite3_result_int64(context, iVal);
      break;
    }
    case SQLITE_NULL: {

      sqlite3_result_null(context);
      break;
    }
    default: {





      double rVal = sqlite3_value_double(argv[0]);
      if( rVal<0 ) rVal = -rVal;
      sqlite3_result_double(context, rVal);
      break;
    }
  }
}
................................................................................
      sqlite3_free(azChar);
    }
  }
  sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
}






#ifdef SQLITE_SOUNDEX
/*
** Compute the soundex encoding of a word.



*/
static void soundexFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  char zResult[8];
................................................................................
    }
    while( j<4 ){
      zResult[j++] = '0';
    }
    zResult[j] = 0;
    sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
  }else{


    sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
  }
}
#endif

#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** A function that loads a shared-library extension then returns NULL.
*/
static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
  const char *zFile = (const char *)sqlite3_value_text(argv[0]);

      sqlite3_result_null(context);
      break;
    }
  }
}

/*
** Implementation of the abs() function.
**
** IMP: R-23979-26855 The abs(X) function returns the absolute value of
** the numeric argument X. 
*/
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  assert( argc==1 );
  UNUSED_PARAMETER(argc);
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_INTEGER: {
      i64 iVal = sqlite3_value_int64(argv[0]);
      if( iVal<0 ){
        if( (iVal<<1)==0 ){
          /* IMP: R-35460-15084 If X is the integer -9223372036854775807 then
          ** abs(X) throws an integer overflow error since there is no
          ** equivalent positive 64-bit two complement value. */
          sqlite3_result_error(context, "integer overflow", -1);
          return;
        }
        iVal = -iVal;
      } 
      sqlite3_result_int64(context, iVal);
      break;
    }
    case SQLITE_NULL: {
      /* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */
      sqlite3_result_null(context);
      break;
    }
    default: {
      /* Because sqlite3_value_double() returns 0.0 if the argument is not
      ** something that can be converted into a number, we have:
      ** IMP: R-57326-31541 Abs(X) return 0.0 if X is a string or blob that
      ** cannot be converted to a numeric value. 
      */
      double rVal = sqlite3_value_double(argv[0]);
      if( rVal<0 ) rVal = -rVal;
      sqlite3_result_double(context, rVal);
      break;
    }
  }
}
................................................................................
      sqlite3_free(azChar);
    }
  }
  sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
}


/* IMP: R-25361-16150 This function is omitted from SQLite by default. It
** is only available if the SQLITE_SOUNDEX compile-time option is used
** when SQLite is built.
*/
#ifdef SQLITE_SOUNDEX
/*
** Compute the soundex encoding of a word.
**
** IMP: R-59782-00072 The soundex(X) function returns a string that is the
** soundex encoding of the string X. 
*/
static void soundexFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  char zResult[8];
................................................................................
    }
    while( j<4 ){
      zResult[j++] = '0';
    }
    zResult[j] = 0;
    sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
  }else{
    /* IMP: R-64894-50321 The string "?000" is returned if the argument
    ** is NULL or contains no ASCII alphabetic characters. */
    sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
  }
}
#endif /* SQLITE_SOUNDEX */

#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*
** A function that loads a shared-library extension then returns NULL.
*/
static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
  const char *zFile = (const char *)sqlite3_value_text(argv[0]);

  va_start(ap, op);
  switch( op ){

    /* Mutex configuration options are only available in a threadsafe
    ** compile. 
    */
#if SQLITE_THREADSAFE
    case SQLITE_CONFIG_SINGLETHREAD: {
      /* Disable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 0;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }
    case SQLITE_CONFIG_MULTITHREAD: {

  va_start(ap, op);
  switch( op ){

    /* Mutex configuration options are only available in a threadsafe
    ** compile. 
    */
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0
    case SQLITE_CONFIG_SINGLETHREAD: {
      /* Disable all mutexing */
      sqlite3GlobalConfig.bCoreMutex = 0;
      sqlite3GlobalConfig.bFullMutex = 0;
      break;
    }
    case SQLITE_CONFIG_MULTITHREAD: {

// check fails.
//
%type refargs {int}
refargs(A) ::= .                  { A = OE_None*0x0101; /* EV: R-19803-45884 */}
refargs(A) ::= refargs(X) refarg(Y). { A = (X & ~Y.mask) | Y.value; }
%type refarg {struct {int value; int mask;}}
refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }

refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }
%type refact {int}
refact(A) ::= SET NULL.              { A = OE_SetNull;  /* EV: R-33326-45252 */}
refact(A) ::= SET DEFAULT.           { A = OE_SetDflt;  /* EV: R-33326-45252 */}
refact(A) ::= CASCADE.               { A = OE_Cascade;  /* EV: R-33326-45252 */}
refact(A) ::= RESTRICT.              { A = OE_Restrict; /* EV: R-33326-45252 */}

// check fails.
//
%type refargs {int}
refargs(A) ::= .                  { A = OE_None*0x0101; /* EV: R-19803-45884 */}
refargs(A) ::= refargs(X) refarg(Y). { A = (X & ~Y.mask) | Y.value; }
%type refarg {struct {int value; int mask;}}
refarg(A) ::= MATCH nm.              { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON INSERT refact.      { A.value = 0;     A.mask = 0x000000; }
refarg(A) ::= ON DELETE refact(X).   { A.value = X;     A.mask = 0x0000ff; }
refarg(A) ::= ON UPDATE refact(X).   { A.value = X<<8;  A.mask = 0x00ff00; }
%type refact {int}
refact(A) ::= SET NULL.              { A = OE_SetNull;  /* EV: R-33326-45252 */}
refact(A) ::= SET DEFAULT.           { A = OE_SetDflt;  /* EV: R-33326-45252 */}
refact(A) ::= CASCADE.               { A = OE_Cascade;  /* EV: R-33326-45252 */}
refact(A) ::= RESTRICT.              { A = OE_Restrict; /* EV: R-33326-45252 */}

static int columnIndex(Table *pTab, const char *zCol){
  int i;
  for(i=0; i<pTab->nCol; i++){
    if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
  }
  return -1;
}


































/*
** This function is used to add terms implied by JOIN syntax to the
** WHERE clause expression of a SELECT statement. The new term, which
** is ANDed with the existing WHERE clause, is of the form:
**
**    (tab1.col1 = tab2.col2)
................................................................................
** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the 
** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is
** column iColRight of tab2.
*/
static void addWhereTerm(
  Parse *pParse,                  /* Parsing context */
  SrcList *pSrc,                  /* List of tables in FROM clause */
  int iSrc,                       /* Index of first table to join in pSrc */
  int iColLeft,                   /* Index of column in first table */

  int iColRight,                  /* Index of column in second table */
  int isOuterJoin,                /* True if this is an OUTER join */
  Expr **ppWhere                  /* IN/OUT: The WHERE clause to add to */
){
  sqlite3 *db = pParse->db;
  Expr *pE1;
  Expr *pE2;
  Expr *pEq;


  assert( pSrc->nSrc>(iSrc+1) );
  assert( pSrc->a[iSrc].pTab );
  assert( pSrc->a[iSrc+1].pTab );

  pE1 = sqlite3CreateColumnExpr(db, pSrc, iSrc, iColLeft);
  pE2 = sqlite3CreateColumnExpr(db, pSrc, iSrc+1, iColRight);

  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
  if( pEq && isOuterJoin ){
    ExprSetProperty(pEq, EP_FromJoin);
    assert( !ExprHasAnyProperty(pEq, EP_TokenOnly|EP_Reduced) );
    ExprSetIrreducible(pEq);
    pEq->iRightJoinTable = (i16)pE2->iTable;
................................................................................
    */
    if( pRight->jointype & JT_NATURAL ){
      if( pRight->pOn || pRight->pUsing ){
        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
           "an ON or USING clause", 0);
        return 1;
      }
      for(j=0; j<pLeftTab->nCol; j++){




        char *zName = pLeftTab->aCol[j].zName;
        int iRightCol = columnIndex(pRightTab, zName);
        if( iRightCol>=0 ){

          addWhereTerm(pParse, pSrc, i, j, iRightCol, isOuter, &p->pWhere);

        }
      }
    }

    /* Disallow both ON and USING clauses in the same join
    */
    if( pRight->pOn && pRight->pUsing ){
................................................................................
    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
    ** Report an error if any column mentioned in the USING clause is
    ** not contained in both tables to be joined.
    */
    if( pRight->pUsing ){
      IdList *pList = pRight->pUsing;
      for(j=0; j<pList->nId; j++){





        char *zName = pList->a[j].zName;
        int iLeftCol = columnIndex(pLeftTab, zName);
        int iRightCol = columnIndex(pRightTab, zName);
        if( iLeftCol<0 || iRightCol<0 ){


          sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
            "not present in both tables", zName);
          return 1;
        }

        addWhereTerm(pParse, pSrc, i, iLeftCol, iRightCol, isOuter, &p->pWhere);
      }
    }
  }
  return 0;
}

/*
................................................................................
            */
            if( IsHiddenColumn(&pTab->aCol[j]) ){
              assert(IsVirtual(pTab));
              continue;
            }

            if( i>0 && zTName==0 ){
              struct SrcList_item *pLeft = &pTabList->a[i-1];
              if( (pLeft[1].jointype & JT_NATURAL)!=0 &&

                        columnIndex(pLeft->pTab, zName)>=0 ){
                /* In a NATURAL join, omit the join columns from the 
                ** table on the right */
                continue;
              }
              if( sqlite3IdListIndex(pLeft[1].pUsing, zName)>=0 ){
                /* In a join with a USING clause, omit columns in the
                ** using clause from the table on the right. */
                continue;
              }
            }
            pRight = sqlite3Expr(db, TK_ID, zName);
            zColname = zName;

static int columnIndex(Table *pTab, const char *zCol){
  int i;
  for(i=0; i<pTab->nCol; i++){
    if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
  }
  return -1;
}

/*
** Search the first N tables in pSrc, from left to right, looking for a
** table that has a column named zCol.  
**
** When found, set *piTab and *piCol to the table index and column index
** of the matching column and return TRUE.
**
** If not found, return FALSE.
*/
static int tableAndColumnIndex(
  SrcList *pSrc,       /* Array of tables to search */
  int N,               /* Number of tables in pSrc->a[] to search */
  const char *zCol,    /* Name of the column we are looking for */
  int *piTab,          /* Write index of pSrc->a[] here */
  int *piCol           /* Write index of pSrc->a[*piTab].pTab->aCol[] here */
){
  int i;               /* For looping over tables in pSrc */
  int iCol;            /* Index of column matching zCol */

  assert( (piTab==0)==(piCol==0) );  /* Both or neither are NULL */
  for(i=0; i<N; i++){
    iCol = columnIndex(pSrc->a[i].pTab, zCol);
    if( iCol>=0 ){
      if( piTab ){
        *piTab = i;
        *piCol = iCol;
      }
      return 1;
    }
  }
  return 0;
}

/*
** This function is used to add terms implied by JOIN syntax to the
** WHERE clause expression of a SELECT statement. The new term, which
** is ANDed with the existing WHERE clause, is of the form:
**
**    (tab1.col1 = tab2.col2)
................................................................................
** where tab1 is the iSrc'th table in SrcList pSrc and tab2 is the 
** (iSrc+1)'th. Column col1 is column iColLeft of tab1, and col2 is
** column iColRight of tab2.
*/
static void addWhereTerm(
  Parse *pParse,                  /* Parsing context */
  SrcList *pSrc,                  /* List of tables in FROM clause */
  int iLeft,                      /* Index of first table to join in pSrc */
  int iColLeft,                   /* Index of column in first table */
  int iRight,                     /* Index of second table in pSrc */
  int iColRight,                  /* Index of column in second table */
  int isOuterJoin,                /* True if this is an OUTER join */
  Expr **ppWhere                  /* IN/OUT: The WHERE clause to add to */
){
  sqlite3 *db = pParse->db;
  Expr *pE1;
  Expr *pE2;
  Expr *pEq;

  assert( iLeft<iRight );
  assert( pSrc->nSrc>iRight );
  assert( pSrc->a[iLeft].pTab );
  assert( pSrc->a[iRight].pTab );

  pE1 = sqlite3CreateColumnExpr(db, pSrc, iLeft, iColLeft);
  pE2 = sqlite3CreateColumnExpr(db, pSrc, iRight, iColRight);

  pEq = sqlite3PExpr(pParse, TK_EQ, pE1, pE2, 0);
  if( pEq && isOuterJoin ){
    ExprSetProperty(pEq, EP_FromJoin);
    assert( !ExprHasAnyProperty(pEq, EP_TokenOnly|EP_Reduced) );
    ExprSetIrreducible(pEq);
    pEq->iRightJoinTable = (i16)pE2->iTable;
................................................................................
    */
    if( pRight->jointype & JT_NATURAL ){
      if( pRight->pOn || pRight->pUsing ){
        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
           "an ON or USING clause", 0);
        return 1;
      }
      for(j=0; j<pRightTab->nCol; j++){
        char *zName;   /* Name of column in the right table */
        int iLeft;     /* Matching left table */
        int iLeftCol;  /* Matching column in the left table */

        zName = pRightTab->aCol[j].zName;


        if( tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol) ){
          addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, j,
                       isOuter, &p->pWhere);
        }
      }
    }

    /* Disallow both ON and USING clauses in the same join
    */
    if( pRight->pOn && pRight->pUsing ){
................................................................................
    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
    ** Report an error if any column mentioned in the USING clause is
    ** not contained in both tables to be joined.
    */
    if( pRight->pUsing ){
      IdList *pList = pRight->pUsing;
      for(j=0; j<pList->nId; j++){
        char *zName;     /* Name of the term in the USING clause */
        int iLeft;       /* Table on the left with matching column name */
        int iLeftCol;    /* Column number of matching column on the left */
        int iRightCol;   /* Column number of matching column on the right */

        zName = pList->a[j].zName;

        iRightCol = columnIndex(pRightTab, zName);
        if( iRightCol<0
         || !tableAndColumnIndex(pSrc, i+1, zName, &iLeft, &iLeftCol)
        ){
          sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
            "not present in both tables", zName);
          return 1;
        }
        addWhereTerm(pParse, pSrc, iLeft, iLeftCol, i+1, iRightCol,
                     isOuter, &p->pWhere);
      }
    }
  }
  return 0;
}

/*
................................................................................
            */
            if( IsHiddenColumn(&pTab->aCol[j]) ){
              assert(IsVirtual(pTab));
              continue;
            }

            if( i>0 && zTName==0 ){

              if( (pFrom->jointype & JT_NATURAL)!=0
                && tableAndColumnIndex(pTabList, i, zName, 0, 0)
              ){
                /* In a NATURAL join, omit the join columns from the 
                ** table to the right of the join */
                continue;
              }
              if( sqlite3IdListIndex(pFrom->pUsing, zName)>=0 ){
                /* In a join with a USING clause, omit columns in the
                ** using clause from the table on the right. */
                continue;
              }
            }
            pRight = sqlite3Expr(db, TK_ID, zName);
            zColname = zName;

# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif

/*
** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100>
**
** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in
** the sqlite3.h file specify the version of SQLite with which
** that header file is associated.
**
** The "version" of SQLite is a string of the form "W.X.Y" or "W.X.Y.Z".
** The W value is major version number and is always 3 in SQLite3.
** The W value only changes when backwards compatibility is
** broken and we intend to never break backwards compatibility.
** The X value is the minor version number and only changes when
** there are major feature enhancements that are forwards compatible
** but not backwards compatible.
** The Y value is the release number and is incremented with
** each release but resets back to 0 whenever X is incremented.
** The Z value only appears on branch releases.
**



** The SQLITE_VERSION_NUMBER is an integer that is computed as
** follows:



**
** <blockquote><pre>
** SQLITE_VERSION_NUMBER = W*1000000 + X*1000 + Y
** </pre></blockquote>
**
** Since version 3.6.18, SQLite source code has been stored in the
** <a href="http://www.fossil-scm.org/">fossil configuration management
** system</a>.  The SQLITE_SOURCE_ID
** macro is a string which identifies a particular check-in of SQLite
** within its configuration management system.  The string contains the
** date and time of the check-in (UTC) and an SHA1 hash of the entire
** source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
**
** Requirements: [H10011] [H10014]
*/
#define SQLITE_VERSION        "--VERS--"
#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
#define SQLITE_SOURCE_ID      "--SOURCE-ID--"

/*
** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100>
** KEYWORDS: sqlite3_version
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] #defines in the header,
** but are associated with the library instead of the header file.  Cautious
** programmers might include assert() statements in their application to
** verify that values returned by these interfaces match the macros in
** the header, and thus insure that the application is
** compiled with matching library and header files.
**
** <blockquote><pre>
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion,SQLITE_VERSION)==0 );
** </pre></blockquote>
**
** The sqlite3_libversion() function returns the same information as is
** in the sqlite3_version[] string constant.  The function is provided
** for use in DLLs since DLL users usually do not have direct access to string
** constants within the DLL.  Similarly, the sqlite3_sourceid() function
** returns the same information as is in the [SQLITE_SOURCE_ID] #define of
** the header file.
**
** See also: [sqlite_version()] and [sqlite_source_id()].
**
** Requirements: [H10021] [H10022] [H10023]

*/
SQLITE_EXTERN const char sqlite3_version[];
const char *sqlite3_libversion(void);
const char *sqlite3_sourceid(void);
int sqlite3_libversion_number(void);

/*
** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100>




**
** SQLite can be compiled with or without mutexes.  When
** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
** are enabled and SQLite is threadsafe.  When the
** [SQLITE_THREADSAFE] macro is 0, 
** the mutexes are omitted.  Without the mutexes, it is not safe
** to use SQLite concurrently from more than one thread.
**
** Enabling mutexes incurs a measurable performance penalty.
** So if speed is of utmost importance, it makes sense to disable
** the mutexes.  But for maximum safety, mutexes should be enabled.
** The default behavior is for mutexes to be enabled.
**
** This interface can be used by an application to make sure that the
** version of SQLite that it is linking against was compiled with
** the desired setting of the [SQLITE_THREADSAFE] macro.
**
** This interface only reports on the compile-time mutex setting
** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
** SQLITE_THREADSAFE=1 then mutexes are enabled by default but
** can be fully or partially disabled using a call to [sqlite3_config()]
** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
** or [SQLITE_CONFIG_MUTEX].  The return value of this function shows
** only the default compile-time setting, not any run-time changes
** to that setting.
**
** See the [threading mode] documentation for additional information.
**
** Requirements: [H10101] [H10102]
*/
int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle {H12000} <S40200>
** KEYWORDS: {database connection} {database connections}
**
** Each open SQLite database is represented by a pointer to an instance of
** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
** is its destructor.  There are many other interfaces (such as
................................................................................
** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
** [sqlite3_busy_timeout()] to name but three) that are methods on an
** sqlite3 object.
*/
typedef struct sqlite3 sqlite3;

/*
** CAPI3REF: 64-Bit Integer Types {H10200} <S10110>
** KEYWORDS: sqlite_int64 sqlite_uint64
**
** Because there is no cross-platform way to specify 64-bit integer types
** SQLite includes typedefs for 64-bit signed and unsigned integers.
**
** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
** The sqlite_int64 and sqlite_uint64 types are supported for backwards
** compatibility only.
**
** Requirements: [H10201] [H10202]



*/
#ifdef SQLITE_INT64_TYPE
  typedef SQLITE_INT64_TYPE sqlite_int64;
  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
  typedef __int64 sqlite_int64;
  typedef unsigned __int64 sqlite_uint64;
................................................................................
** substitute integer for floating-point.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif

/*
** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200>
**
** This routine is the destructor for the [sqlite3] object.


**
** Applications must [sqlite3_finalize | finalize] all [prepared statements]
** and [sqlite3_blob_close | close] all [BLOB handles] associated with
** the [sqlite3] object prior to attempting to close the object.



**
** If [sqlite3_close()] is invoked while a transaction is open,
** the transaction is automatically rolled back.
**
** The C parameter to [sqlite3_close(C)] must be either a NULL
** pointer or an [sqlite3] object pointer obtained
** from [sqlite3_open()], [sqlite3_open16()], or
** [sqlite3_open_v2()], and not previously closed.
**
** Requirements:
** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019]
*/
int sqlite3_close(sqlite3 *);

/*
** The type for a callback function.
** This is legacy and deprecated.  It is included for historical
** compatibility and is not documented.
*/
typedef int (*sqlite3_callback)(void*,int,char**, char**);

/*
** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000>
**
** The sqlite3_exec() interface is a convenient way of running one or more

** SQL statements without having to write a lot of C code.  The UTF-8 encoded
** SQL statements are passed in as the second parameter to sqlite3_exec().
** The statements are evaluated one by one until either an error or
** an interrupt is encountered, or until they are all done.  The 3rd parameter
** is an optional callback that is invoked once for each row of any query
** results produced by the SQL statements.  The 5th parameter tells where
** to write any error messages.
**





** The error message passed back through the 5th parameter is held
** in memory obtained from [sqlite3_malloc()].  To avoid a memory leak,
** the calling application should call [sqlite3_free()] on any error
** message returned through the 5th parameter when it has finished using
** the error message.
**
** If the SQL statement in the 2nd parameter is NULL or an empty string
** or a string containing only whitespace and comments, then no SQL
** statements are evaluated and the database is not changed.
**
** The sqlite3_exec() interface is implemented in terms of
** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].
** The sqlite3_exec() routine does nothing to the database that cannot be done
** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()].



**
** The first parameter to [sqlite3_exec()] must be an valid and open
** [database connection].



**
** The database connection must not be closed while
** [sqlite3_exec()] is running.









**
** The calling function should use [sqlite3_free()] to free
** the memory that *errmsg is left pointing at once the error
** message is no longer needed.




**
** The SQL statement text in the 2nd parameter to [sqlite3_exec()]
** must remain unchanged while [sqlite3_exec()] is running.

**
** Requirements:
** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116]
** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138]








*/
int sqlite3_exec(
  sqlite3*,                                  /* An open database */
  const char *sql,                           /* SQL to be evaluated */
  int (*callback)(void*,int,char**,char**),  /* Callback function */
  void *,                                    /* 1st argument to callback */
  char **errmsg                              /* Error msg written here */
);

/*
** CAPI3REF: Result Codes {H10210} <S10700>
** KEYWORDS: SQLITE_OK {error code} {error codes}
** KEYWORDS: {result code} {result codes}
**
** Many SQLite functions return an integer result code from the set shown
** here in order to indicates success or failure.
**
** New error codes may be added in future versions of SQLite.
................................................................................
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
/* end-of-error-codes */

/*
** CAPI3REF: Extended Result Codes {H10220} <S10700>
** KEYWORDS: {extended error code} {extended error codes}
** KEYWORDS: {extended result code} {extended result codes}
**
** In its default configuration, SQLite API routines return one of 26 integer
** [SQLITE_OK | result codes].  However, experience has shown that many of
** these result codes are too coarse-grained.  They do not provide as
** much information about problems as programmers might like.  In an effort to
................................................................................
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED | (1<<8) )

/*
** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700>
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the xOpen method of the
** [sqlite3_vfs] object.
*/
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
................................................................................
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */

/*
** CAPI3REF: Device Characteristics {H10240} <H11120>
**
** The xDeviceCapabilities method of the [sqlite3_io_methods]
** object returns an integer which is a vector of the these
** bit values expressing I/O characteristics of the mass storage
** device that holds the file that the [sqlite3_io_methods]
** refers to.
**
................................................................................
#define SQLITE_IOCAP_ATOMIC16K       0x00000040
#define SQLITE_IOCAP_ATOMIC32K       0x00000080
#define SQLITE_IOCAP_ATOMIC64K       0x00000100
#define SQLITE_IOCAP_SAFE_APPEND     0x00000200
#define SQLITE_IOCAP_SEQUENTIAL      0x00000400

/*
** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310>
**
** SQLite uses one of these integer values as the second
** argument to calls it makes to the xLock() and xUnlock() methods
** of an [sqlite3_io_methods] object.
*/
#define SQLITE_LOCK_NONE          0
#define SQLITE_LOCK_SHARED        1
#define SQLITE_LOCK_RESERVED      2
#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4

/*
** CAPI3REF: Synchronization Type Flags {H10260} <H11120>
**
** When SQLite invokes the xSync() method of an
** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
................................................................................
** to use Mac OS X style fullsync instead of fsync().
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010

/*
** CAPI3REF: OS Interface Open File Handle {H11110} <S20110>
**
** An [sqlite3_file] object represents an open file in the 
** [sqlite3_vfs | OS interface layer].  Individual OS interface
** implementations will
** want to subclass this object by appending additional fields
** for their own use.  The pMethods entry is a pointer to an
** [sqlite3_io_methods] object that defines methods for performing
................................................................................
*/
typedef struct sqlite3_file sqlite3_file;
struct sqlite3_file {
  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
};

/*
** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110>
**
** Every file opened by the [sqlite3_vfs] xOpen method populates an
** [sqlite3_file] object (or, more commonly, a subclass of the
** [sqlite3_file] object) with a pointer to an instance of this object.
** This object defines the methods used to perform various operations
** against the open file represented by the [sqlite3_file] object.
**
................................................................................
  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
  int (*xSectorSize)(sqlite3_file*);
  int (*xDeviceCharacteristics)(sqlite3_file*);
  /* Additional methods may be added in future releases */
};

/*
** CAPI3REF: Standard File Control Opcodes {H11310} <S30800>
**
** These integer constants are opcodes for the xFileControl method
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
** interface.
**
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
................................................................................
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4

/*
** CAPI3REF: Mutex Handle {H17110} <S20130>
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
** deals with pointers to the [sqlite3_mutex] object.
**
** Mutexes are created using [sqlite3_mutex_alloc()].
*/
typedef struct sqlite3_mutex sqlite3_mutex;

/*
** CAPI3REF: OS Interface Object {H11140} <S20100>
**
** An instance of the sqlite3_vfs object defines the interface between
** the SQLite core and the underlying operating system.  The "vfs"
** in the name of the object stands for "virtual file system".
**
** The value of the iVersion field is initially 1 but may be larger in
** future versions of SQLite.  Additional fields may be appended to this
................................................................................
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  int (*xGetLastError)(sqlite3_vfs*, int, char *);
  /* New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. */
};

/*
** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140>
**
** These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object. {END}  They determine
** what kind of permissions the xAccess method is looking for.
** With SQLITE_ACCESS_EXISTS, the xAccess method
** simply checks whether the file exists.
** With SQLITE_ACCESS_READWRITE, the xAccess method
** checks whether the file is both readable and writable.
** With SQLITE_ACCESS_READ, the xAccess method
** checks whether the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2

/*
** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100>
**
** The sqlite3_initialize() routine initializes the
** SQLite library.  The sqlite3_shutdown() routine
** deallocates any resources that were allocated by sqlite3_initialize().
** These routines are designed to aid in process initialization and
** shutdown on embedded systems.  Workstation applications using
** SQLite normally do not need to invoke either of these routines.
**
** A call to sqlite3_initialize() is an "effective" call if it is
** the first time sqlite3_initialize() is invoked during the lifetime of
** the process, or if it is the first time sqlite3_initialize() is invoked
** following a call to sqlite3_shutdown().  Only an effective call
** of sqlite3_initialize() does any initialization.  All other calls
** are harmless no-ops.
**
** A call to sqlite3_shutdown() is an "effective" call if it is the first
** call to sqlite3_shutdown() since the last sqlite3_initialize().  Only
** an effective call to sqlite3_shutdown() does any deinitialization.
** All other valid calls to sqlite3_shutdown() are harmless no-ops.
**
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
** is not.  The sqlite3_shutdown() interface must only be called from a
** single thread.  All open [database connections] must be closed and all
** other SQLite resources must be deallocated prior to invoking
** sqlite3_shutdown().
**
** Among other things, sqlite3_initialize() will invoke
** sqlite3_os_init().  Similarly, sqlite3_shutdown()
** will invoke sqlite3_os_end().
**
** The sqlite3_initialize() routine returns [SQLITE_OK] on success.
** If for some reason, sqlite3_initialize() is unable to initialize
** the library (perhaps it is unable to allocate a needed resource such
** as a mutex) it returns an [error code] other than [SQLITE_OK].
**
** The sqlite3_initialize() routine is called internally by many other
** SQLite interfaces so that an application usually does not need to
** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
** calls sqlite3_initialize() so the SQLite library will be automatically
** initialized when [sqlite3_open()] is called if it has not be initialized
** already.  However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
** compile-time option, then the automatic calls to sqlite3_initialize()
** are omitted and the application must call sqlite3_initialize() directly
** prior to using any other SQLite interface.  For maximum portability,
** it is recommended that applications always invoke sqlite3_initialize()
** directly prior to using any other SQLite interface.  Future releases
** of SQLite may require this.  In other words, the behavior exhibited
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
................................................................................
*/
int sqlite3_initialize(void);
int sqlite3_shutdown(void);
int sqlite3_os_init(void);
int sqlite3_os_end(void);

/*
** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200>
** EXPERIMENTAL
**
** The sqlite3_config() interface is used to make global configuration
** changes to SQLite in order to tune SQLite to the specific needs of
** the application.  The default configuration is recommended for most
** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.
**
** The sqlite3_config() interface is not threadsafe.  The application
** must insure that no other SQLite interfaces are invoked by other
** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
** may only be invoked prior to library initialization using
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].


** Note, however, that sqlite3_config() can be called as part of the
** implementation of an application-defined [sqlite3_os_init()].
**
** The first argument to sqlite3_config() is an integer
** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines
** what property of SQLite is to be configured.  Subsequent arguments
** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]
** in the first argument.
**
** When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
** If the option is unknown or SQLite is unable to set the option
** then this routine returns a non-zero [error code].
**
** Requirements:
** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135]
** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159]
** [H14162] [H14165] [H14168]
*/
SQLITE_EXPERIMENTAL int sqlite3_config(int, ...);

/*
** CAPI3REF: Configure database connections  {H14200} <S20000>
** EXPERIMENTAL
**
** The sqlite3_db_config() interface is used to make configuration
** changes to a [database connection].  The interface is similar to
** [sqlite3_config()] except that the changes apply to a single
** [database connection] (specified in the first argument).  The
** sqlite3_db_config() interface can only be used immediately after
** the database connection is created using [sqlite3_open()],
** [sqlite3_open16()], or [sqlite3_open_v2()].  
**
** The second argument to sqlite3_db_config(D,V,...)  is the
** configuration verb - an integer code that indicates what
** aspect of the [database connection] is being configured.
** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
** New verbs are likely to be added in future releases of SQLite.
** Additional arguments depend on the verb.
**
** Requirements:
** [H14203] [H14206] [H14209] [H14212] [H14215]
*/
SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...);

/*
** CAPI3REF: Memory Allocation Routines {H10155} <S20120>
** EXPERIMENTAL
**
** An instance of this object defines the interface between SQLite
** and low-level memory allocation routines.
**
** This object is used in only one place in the SQLite interface.
** A pointer to an instance of this object is the argument to
................................................................................
** conditions.
**
** The xMalloc and xFree methods must work like the
** malloc() and free() functions from the standard C library.
** The xRealloc method must work like realloc() from the standard C library
** with the exception that if the second argument to xRealloc is zero,
** xRealloc must be a no-op - it must not perform any allocation or
** deallocation.  SQLite guaranteeds that the second argument to
** xRealloc is always a value returned by a prior call to xRoundup.
** And so in cases where xRoundup always returns a positive number,
** xRealloc can perform exactly as the standard library realloc() and
** still be in compliance with this specification.
**
** xSize should return the allocated size of a memory allocation
** previously obtained from xMalloc or xRealloc.  The allocated size
................................................................................
  int (*xRoundup)(int);          /* Round up request size to allocation size */
  int (*xInit)(void*);           /* Initialize the memory allocator */
  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
  void *pAppData;                /* Argument to xInit() and xShutdown() */
};

/*
** CAPI3REF: Configuration Options {H10160} <S20000>
** EXPERIMENTAL
**
** These constants are the available integer configuration options that
** can be passed as the first argument to the [sqlite3_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
................................................................................
** should check the return code from [sqlite3_config()] to make sure that
** the call worked.  The [sqlite3_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
** <dd>There are no arguments to this option.  This option disables

** all mutexing and puts SQLite into a mode where it can only be used
** by a single thread.</dd>





**
** <dt>SQLITE_CONFIG_MULTITHREAD</dt>
** <dd>There are no arguments to this option.  This option disables

** mutexing on [database connection] and [prepared statement] objects.
** The application is responsible for serializing access to
** [database connections] and [prepared statements].  But other mutexes
** are enabled so that SQLite will be safe to use in a multi-threaded
** environment as long as no two threads attempt to use the same
** [database connection] at the same time.  See the [threading mode]
** documentation for additional information.</dd>



**
** <dt>SQLITE_CONFIG_SERIALIZED</dt>
** <dd>There are no arguments to this option.  This option enables

** all mutexes including the recursive
** mutexes on [database connection] and [prepared statement] objects.
** In this mode (which is the default when SQLite is compiled with
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
** to [database connections] and [prepared statements] so that the
** application is free to use the same [database connection] or the
** same [prepared statement] in different threads at the same time.
** See the [threading mode] documentation for additional information.</dd>




**
** <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The argument specifies
** alternative low-level memory allocation routines to be used in place of
** the memory allocation routines built into SQLite.</dd>


**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
** structure is filled with the currently defined memory allocation routines.
** This option can be used to overload the default memory allocation
** routines with a wrapper that simulations memory allocation failure or
** tracks memory usage, for example.</dd>
**
** <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd>This option takes single argument of type int, interpreted as a 
** boolean, which enables or disables the collection of memory allocation 

** statistics. When disabled, the following SQLite interfaces become 
** non-operational:
**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit()]
**   <li> [sqlite3_status()]
**   </ul>



** </dd>
**
** <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** scratch memory.  There are three arguments:  A pointer an 8-byte
** aligned memory buffer from which the scrach allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N).  The sz
** argument must be a multiple of 16. The sz parameter should be a few bytes
** larger than the actual scratch space required due to internal overhead.
** The first argument should pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** SQLite will use no more than one scratch buffer at once per thread, so
** N should be set to the expected maximum number of threads.  The sz
** parameter should be 6 times the size of the largest database page size.
** Scratch buffers are used as part of the btree balance operation.  If
** The btree balancer needs additional memory beyond what is provided by
** scratch buffers or if no scratch buffer space is specified, then SQLite
** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd>
**
** <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd>This option specifies a static memory buffer that SQLite can use for
** the database page cache with the default page cache implemenation.  
** This configuration should not be used if an application-define page
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
** There are three arguments to this option: A pointer to 8-byte aligned
** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument should be the size of the largest database page
** (a power of two between 512 and 32768) plus a little extra for each
** page header.  The page header size is 20 to 40 bytes depending on
** the host architecture.  It is harmless, apart from the wasted memory,
** to make sz a little too large.  The first
** argument should point to an allocation of at least sz*N bytes of memory.
** SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
** The implementation might use one or more of the N buffers to hold 
** memory accounting information. The pointer in the first argument must
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
** will be undefined.</dd>
**
** <dt>SQLITE_CONFIG_HEAP</dt>
** <dd>This option specifies a static memory buffer that SQLite will use
** for all of its dynamic memory allocation needs beyond those provided
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
** There are three arguments: An 8-byte aligned pointer to the memory,
** the number of bytes in the memory buffer, and the minimum allocation size.
** If the first pointer (the memory pointer) is NULL, then SQLite reverts
** to using its default memory allocator (the system malloc() implementation),
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  If the
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
** allocator is engaged to handle all of SQLites memory allocation needs.
** The first pointer (the memory pointer) must be aligned to an 8-byte
** boundary or subsequent behavior of SQLite will be undefined.</dd>
**
** <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
** alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.</dd>






**
** <dt>SQLITE_CONFIG_GETMUTEX</dt>
** <dd>This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_methods]
** structure is filled with the currently defined mutex routines.
** This option can be used to overload the default mutex allocation
** routines with a wrapper used to track mutex usage for performance
** profiling or testing, for example.</dd>




**
** <dt>SQLITE_CONFIG_LOOKASIDE</dt>
** <dd>This option takes two arguments that determine the default

** memory allocation lookaside optimization.  The first argument is the
** size of each lookaside buffer slot and the second is the number of
** slots allocated to each database connection.  This option sets the
** <i>default</i> lookaside size.  The [SQLITE_DBCONFIG_LOOKASIDE]
** verb to [sqlite3_db_config()] can be used to change the lookaside
** configuration on individual connections.</dd>
**
** <dt>SQLITE_CONFIG_PCACHE</dt>
** <dd>This option takes a single argument which is a pointer to
** an [sqlite3_pcache_methods] object.  This object specifies the interface
** to a custom page cache implementation.  SQLite makes a copy of the
** object and uses it for page cache memory allocations.</dd>
**
** <dt>SQLITE_CONFIG_GETPCACHE</dt>
** <dd>This option takes a single argument which is a pointer to an
** [sqlite3_pcache_methods] object.  SQLite copies of the current
** page cache implementation into that object.</dd>
**
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
................................................................................
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
#define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
#define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */

/*
** CAPI3REF: Configuration Options {H10170} <S20000>
** EXPERIMENTAL
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
** should check the return code from [sqlite3_db_config()] to make sure that
** the call worked.  The [sqlite3_db_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
** <dd>This option takes three additional arguments that determine the 
** [lookaside memory allocator] configuration for the [database connection].
** The first argument (the third parameter to [sqlite3_db_config()] is a
** pointer to an memory buffer to use for lookaside memory.

** The first argument may be NULL in which case SQLite will allocate the
** lookaside buffer itself using [sqlite3_malloc()].  The second argument is the
** size of each lookaside buffer slot and the third argument is the number of
** slots.  The size of the buffer in the first argument must be greater than
** or equal to the product of the second and third arguments.  The buffer
** must be aligned to an 8-byte boundary.  If the second argument is not

** a multiple of 8, it is internally rounded down to the next smaller
** multiple of 8.  See also: [SQLITE_CONFIG_LOOKASIDE]</dd>
**
** </dl>
*/
#define SQLITE_DBCONFIG_LOOKASIDE    1001  /* void* int int */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700>
**
** The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. The extended result
** codes are disabled by default for historical compatibility considerations.
**
** Requirements:
** [H12201] [H12202]
*/
int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid {H12220} <S10700>
**
** Each entry in an SQLite table has a unique 64-bit signed
** integer key called the [ROWID | "rowid"]. The rowid is always available
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
** names are not also used by explicitly declared columns. If
** the table has a column of type [INTEGER PRIMARY KEY] then that column
** is another alias for the rowid.
**
** This routine returns the [rowid] of the most recent
** successful [INSERT] into the database from the [database connection]
** in the first argument.  If no successful [INSERT]s
** have ever occurred on that database connection, zero is returned.
**
** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted
** row is returned by this routine as long as the trigger is running.
** But once the trigger terminates, the value returned by this routine
** reverts to the last value inserted before the trigger fired.
**
** An [INSERT] that fails due to a constraint violation is not a
** successful [INSERT] and does not change the value returned by this
** routine.  Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
** and INSERT OR ABORT make no changes to the return value of this
** routine when their insertion fails.  When INSERT OR REPLACE
** encounters a constraint violation, it does not fail.  The
** INSERT continues to completion after deleting rows that caused
** the constraint problem so INSERT OR REPLACE will always change
** the return value of this interface.
**
** For the purposes of this routine, an [INSERT] is considered to
** be successful even if it is subsequently rolled back.
**
** This function is accessible to SQL statements via the
** [last_insert_rowid() SQL function].
**
** Requirements:
** [H12221] [H12223]
**
** If a separate thread performs a new [INSERT] on the same
** database connection while the [sqlite3_last_insert_rowid()]
** function is running and thus changes the last insert [rowid],
** then the value returned by [sqlite3_last_insert_rowid()] is
** unpredictable and might not equal either the old or the new
** last insert [rowid].
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600>
**
** This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the [database connection] specified by the first parameter.
** Only changes that are directly specified by the [INSERT], [UPDATE],
** or [DELETE] statement are counted.  Auxiliary changes caused by
** triggers or [foreign key actions] are not counted. Use the
** [sqlite3_total_changes()] function to find the total number of changes
** including changes caused by triggers and foreign key actions.
**
** Changes to a view that are simulated by an [INSTEAD OF trigger]
** are not counted.  Only real table changes are counted.
**
** A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of [REPLACE] constraint resolution,
** rollback, ABORT processing, [DROP TABLE], or by any other
** mechanisms do not count as direct row changes.
**
** A "trigger context" is a scope of execution that begins and
** ends with the script of a [CREATE TRIGGER | trigger]. 
** Most SQL statements are
** evaluated outside of any trigger.  This is the "top level"
** trigger context.  If a trigger fires from the top level, a
** new trigger context is entered for the duration of that one
** trigger.  Subtriggers create subcontexts for their duration.
**
** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** Thus, when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.  Within the body of a trigger,
** the sqlite3_changes() interface can be called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the same trigger.
** However, the number returned does not include changes
** caused by subtriggers since those have their own context.
**
** See also the [sqlite3_total_changes()] interface, the
** [count_changes pragma], and the [changes() SQL function].
**
** Requirements:
** [H12241] [H12243]
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_changes()] is running then the value returned
** is unpredictable and not meaningful.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600>
**
** This function returns the number of row changes caused by [INSERT],
** [UPDATE] or [DELETE] statements since the [database connection] was opened.

** The count includes all changes from all [CREATE TRIGGER | trigger] 
** contexts and changes made by [foreign key actions]. However,
** the count does not include changes used to implement [REPLACE] constraints,
** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
** count does not include rows of views that fire an [INSTEAD OF trigger],
** though if the INSTEAD OF trigger makes changes of its own, those changes 
** are counted.
** The changes are counted as soon as the statement that makes them is
** completed (when the statement handle is passed to [sqlite3_reset()] or
** [sqlite3_finalize()]).
**
** See also the [sqlite3_changes()] interface, the
** [count_changes pragma], and the [total_changes() SQL function].
**
** Requirements:
** [H12261] [H12263]
**
** If a separate thread makes changes on the same database connection
** while [sqlite3_total_changes()] is running then the value
** returned is unpredictable and not meaningful.
*/
int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500>
**
** This function causes any pending database operation to abort and
** return at its earliest opportunity. This routine is typically
** called in response to a user action such as pressing "Cancel"
** or Ctrl-C where the user wants a long query operation to halt
** immediately.
**
** It is safe to call this routine from a thread different from the
** thread that is currently running the database operation.  But it
** is not safe to call this routine with a [database connection] that
** is closed or might close before sqlite3_interrupt() returns.
**
** If an SQL operation is very nearly finished at the time when
** sqlite3_interrupt() is called, then it might not have an opportunity
** to be interrupted and might continue to completion.
**
** An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
** that is inside an explicit transaction, then the entire transaction
** will be rolled back automatically.
**
** The sqlite3_interrupt(D) call is in effect until all currently running
** SQL statements on [database connection] D complete.  Any new SQL statements
** that are started after the sqlite3_interrupt() call and before the 
** running statements reaches zero are interrupted as if they had been
** running prior to the sqlite3_interrupt() call.  New SQL statements
** that are started after the running statement count reaches zero are
** not effected by the sqlite3_interrupt().
** A call to sqlite3_interrupt(D) that occurs when there are no running
** SQL statements is a no-op and has no effect on SQL statements
** that are started after the sqlite3_interrupt() call returns.
**
** Requirements:
** [H12271] [H12272]
**
** If the database connection closes while [sqlite3_interrupt()]
** is running then bad things will likely happen.
*/
void sqlite3_interrupt(sqlite3*);

/*
** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200>
**
** These routines are useful during command-line input to determine if the
** currently entered text seems to form a complete SQL statement or
** if additional input is needed before sending the text into
** SQLite for parsing.  These routines return 1 if the input string
** appears to be a complete SQL statement.  A statement is judged to be
** complete if it ends with a semicolon token and is not a prefix of a
** well-formed CREATE TRIGGER statement.  Semicolons that are embedded within
** string literals or quoted identifier names or comments are not
** independent tokens (they are part of the token in which they are
** embedded) and thus do not count as a statement terminator.  Whitespace
** and comments that follow the final semicolon are ignored.
**
** These routines return 0 if the statement is incomplete.  If a
** memory allocation fails, then SQLITE_NOMEM is returned.
**
** These routines do not parse the SQL statements thus
** will not detect syntactically incorrect SQL.
**
** If SQLite has not been initialized using [sqlite3_initialize()] prior 
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
** automatically by sqlite3_complete16().  If that initialization fails,
** then the return value from sqlite3_complete16() will be non-zero
** regardless of whether or not the input SQL is complete.
**
** Requirements: [H10511] [H10512]
**
** The input to [sqlite3_complete()] must be a zero-terminated
** UTF-8 string.
**
** The input to [sqlite3_complete16()] must be a zero-terminated
** UTF-16 string in native byte order.
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400>
**
** This routine sets a callback function that might be invoked whenever
** an attempt is made to open a database table that another thread
** or process has locked.
**
** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock. If the busy callback
** is not NULL, then the callback will be invoked with two arguments.
**
** The first argument to the handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler().  The second argument to
** the handler callback is the number of times that the busy handler has
** been invoked for this locking event.  If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
** If the callback returns non-zero, then another attempt
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that it will be invoked
** when there is lock contention. If SQLite determines that invoking the busy
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock.  The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first.  If both processes
** invoke the busy handlers, neither will make any progress.  Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** The default busy callback is NULL.
**
** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache.  SQLite will
** already hold a RESERVED lock on the database file, but it needs
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
** forces an automatic rollback of the changes.  See the
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**
** There can only be a single busy handler defined for each
** [database connection].  Setting a new busy handler clears any
** previously set handler.  Note that calling [sqlite3_busy_timeout()]
** will also set or clear the busy handler.
**
** The busy callback should not take any actions which modify the
** database connection that invoked the busy handler.  Any such actions
** result in undefined behavior.
** 
** Requirements:
** [H12311] [H12312] [H12314] [H12316] [H12318]
**
** A busy handler must not close the database connection
** or [prepared statement] that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout {H12340} <S40410>
**
** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
** for a specified amount of time when a table is locked.  The handler
** will sleep multiple times until at least "ms" milliseconds of sleeping
** have accumulated. {H12343} After "ms" milliseconds of sleeping,
** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** There can only be a single busy handler for a particular
** [database connection] any any given moment.  If another busy handler
** was defined  (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.
**
** Requirements:
** [H12341] [H12343] [H12344]
*/
int sqlite3_busy_timeout(sqlite3*, int ms);

/*
** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000>
**
** Definition: A <b>result table</b> is memory data structure created by the
** [sqlite3_get_table()] interface.  A result table records the
** complete query results from one or more queries.
**
** The table conceptually has a number of rows and columns.  But
** these numbers are not part of the result table itself.  These
................................................................................
**        azResult&#91;3] = "43";
**        azResult&#91;4] = "Bob";
**        azResult&#91;5] = "28";
**        azResult&#91;6] = "Cindy";
**        azResult&#91;7] = "21";
** </pre></blockquote>
**
** The sqlite3_get_table() function evaluates one or more
** semicolon-separated SQL statements in the zero-terminated UTF-8
** string of its 2nd parameter.  It returns a result table to the
** pointer given in its 3rd parameter.
**
** After the calling function has finished using the result, it should
** pass the pointer to the result table to sqlite3_free_table() in order to
** release the memory that was malloced.  Because of the way the
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
** function must not try to call [sqlite3_free()] directly.  Only
** [sqlite3_free_table()] is able to release the memory properly and safely.
**
** The sqlite3_get_table() interface is implemented as a wrapper around
** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
** to any internal data structures of SQLite.  It uses only the public
** interface defined here.  As a consequence, errors that occur in the
** wrapper layer outside of the internal [sqlite3_exec()] call are not
** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()].
**
** Requirements:
** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382]
*/
int sqlite3_get_table(
  sqlite3 *db,          /* An open database */
  const char *zSql,     /* SQL to be evaluated */
  char ***pazResult,    /* Results of the query */
  int *pnRow,           /* Number of result rows written here */
  int *pnColumn,        /* Number of result columns written here */
  char **pzErrmsg       /* Error msg written here */
);
void sqlite3_free_table(char **result);

/*
** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000>
**
** These routines are work-alikes of the "printf()" family of functions
** from the standard C library.
**
** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
** results into memory obtained from [sqlite3_malloc()].
** The strings returned by these two routines should be
** released by [sqlite3_free()].  Both routines return a
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
** memory to hold the resulting string.
**
** In sqlite3_snprintf() routine is similar to "snprintf()" from
** the standard C library.  The result is written into the
** buffer supplied as the second parameter whose size is given by
** the first parameter. Note that the order of the
** first two parameters is reversed from snprintf().  This is an
** historical accident that cannot be fixed without breaking
** backwards compatibility.  Note also that sqlite3_snprintf()
** returns a pointer to its buffer instead of the number of
** characters actually written into the buffer.  We admit that
** the number of characters written would be a more useful return
** value but we cannot change the implementation of sqlite3_snprintf()
** now without breaking compatibility.
**
** As long as the buffer size is greater than zero, sqlite3_snprintf()
** guarantees that the buffer is always zero-terminated.  The first
** parameter "n" is the total size of the buffer, including space for
** the zero terminator.  So the longest string that can be completely
** written will be n-1 characters.
**
** These routines all implement some additional formatting
** options that are useful for constructing SQL statements.
** All of the usual printf() formatting options apply.  In addition, there
** is are "%q", "%Q", and "%z" options.
**
** The %q option works like %s in that it substitutes a null-terminated
** string from the argument list.  But %q also doubles every '\'' character.
** %q is designed for use inside a string literal.  By doubling each '\''
** character it escapes that character and allows it to be inserted into
** the string.
**
** For example, assume the string variable zText contains text as follows:
**
** <blockquote><pre>
**  char *zText = "It's a happy day!";
................................................................................
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It's a happy day!');
** </pre></blockquote>
**
** This second example is an SQL syntax error.  As a general rule you should
** always use %q instead of %s when inserting text into a string literal.
**
** The %Q option works like %q except it also adds single quotes around
** the outside of the total string.  Additionally, if the parameter in the
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
** single quotes) in place of the %Q option.  So, for example, one could say:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** The code above will render a correct SQL statement in the zSQL
** variable even if the zText variable is a NULL pointer.
**
** The "%z" formatting option works exactly like "%s" with the
** addition that after the string has been read and copied into
** the result, [sqlite3_free()] is called on the input string. {END}
**
** Requirements:
** [H17403] [H17406] [H17407]
*/
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000>
**
** The SQLite core  uses these three routines for all of its own
** internal memory allocation needs. "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The
** Windows VFS uses native malloc() and free() for some operations.
**
** The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.
**
** Calling sqlite3_free() with a pointer previously returned
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
** that it might be reused.  The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
**
** The sqlite3_realloc() interface attempts to resize a
** prior memory allocation to be at least N bytes, where N is the
** second parameter.  The memory allocation to be resized is the first
** parameter.  If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** If M is the size of the prior allocation, then min(N,M) bytes
** of the prior allocation are copied into the beginning of buffer returned
** by sqlite3_realloc() and the prior allocation is freed.
** If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary. {END}
**
** The default implementation of the memory allocation subsystem uses
** the malloc(), realloc() and free() provided by the standard C library.
** {H17382} However, if SQLite is compiled with the
** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i>
** is an integer), then SQLite create a static array of at least
** <i>NNN</i> bytes in size and uses that array for all of its dynamic
** memory allocation needs. {END}  Additional memory allocator options
** may be added in future releases.
**
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
** implementation of these routines to be omitted.  That capability
** is no longer provided.  Only built-in memory allocators can be used.
**
** The Windows OS interface layer calls
................................................................................
** the system malloc() and free() directly when converting
** filenames between the UTF-8 encoding used by SQLite
** and whatever filename encoding is used by the particular Windows
** installation.  Memory allocation errors are detected, but
** they are reported back as [SQLITE_CANTOPEN] or
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
**
** Requirements:
** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318]
** [H17321] [H17322] [H17323]
**
** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
** must be either NULL or else pointers obtained from a prior
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
** not yet been released.
**
** The application must not read or write any part of
** a block of memory after it has been released using
................................................................................
** [sqlite3_free()] or [sqlite3_realloc()].
*/
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics {H17370} <S30210>
**
** SQLite provides these two interfaces for reporting on the status
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
** routines, which form the built-in memory allocation subsystem.
**
** Requirements:
** [H17371] [H17373] [H17374] [H17375]













*/
sqlite3_int64 sqlite3_memory_used(void);
sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000>
**
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random [ROWID | ROWIDs] when inserting new records into a table that
** already uses the largest possible [ROWID].  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** applications to access the same PRNG for other purposes.
**
** A call to this routine stores N bytes of randomness into buffer P.
**
** The first time this routine is invoked (either internally or by
** the application) the PRNG is seeded using randomness obtained
** from the xRandomness method of the default [sqlite3_vfs] object.
** On all subsequent invocations, the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.
**
** Requirements:
** [H17392]
*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100>
**
** This routine registers a authorizer callback with a particular
** [database connection], supplied in the first argument.
** The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  The authorizer callback should
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
** specific action but allow the SQL statement to continue to be
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
** rejected with an error.  If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer will fail with an error message.
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  When the callback returns [SQLITE_DENY], the
** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer will fail with an error message explaining that
** access is denied. 
**
** The first parameter to the authorizer callback is a copy of the third
** parameter to the sqlite3_set_authorizer() interface. The second parameter
** to the callback is an integer [SQLITE_COPY | action code] that specifies
** the particular action to be authorized. The third through sixth parameters
** to the callback are zero-terminated strings that contain additional
** details about the action to be authorized.
**
** If the action code is [SQLITE_READ]
** and the callback returns [SQLITE_IGNORE] then the
** [prepared statement] statement is constructed to substitute
** a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
** return can be used to deny an untrusted user access to individual
** columns of a table.
** If the action code is [SQLITE_DELETE] and the callback returns
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
** [truncate optimization] is disabled and all rows are deleted individually.
**
** An authorizer is used when [sqlite3_prepare | preparing]
** SQL statements from an untrusted source, to ensure that the SQL statements
** do not try to access data they are not allowed to see, or that they do not
** try to execute malicious statements that damage the database.  For
................................................................................
** disallows everything except [SELECT] statements.
**
** Applications that need to process SQL from untrusted sources
** might also consider lowering resource limits using [sqlite3_limit()]
** and limiting database size using the [max_page_count] [PRAGMA]
** in addition to using an authorizer.
**
** Only a single authorizer can be in place on a database connection
** at a time.  Each call to sqlite3_set_authorizer overrides the
** previous call.  Disable the authorizer by installing a NULL callback.
** The authorizer is disabled by default.
**
** The authorizer callback must not do anything that will modify
** the database connection that invoked the authorizer callback.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** When [sqlite3_prepare_v2()] is used to prepare a statement, the
** statement might be re-prepared during [sqlite3_step()] due to a 
** schema change.  Hence, the application should ensure that the
** correct authorizer callback remains in place during the [sqlite3_step()].
**
** Note that the authorizer callback is invoked only during
** [sqlite3_prepare()] or its variants.  Authorization is not
** performed during statement evaluation in [sqlite3_step()], unless
** as stated in the previous paragraph, sqlite3_step() invokes
** sqlite3_prepare_v2() to reprepare a statement after a schema change.
**
** Requirements:
** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510]
** [H12511] [H12512] [H12520] [H12521] [H12522]
*/
int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);

/*
** CAPI3REF: Authorizer Return Codes {H12590} <H12500>
**
** The [sqlite3_set_authorizer | authorizer callback function] must
** return either [SQLITE_OK] or one of these two constants in order
** to signal SQLite whether or not the action is permitted.  See the
** [sqlite3_set_authorizer | authorizer documentation] for additional
** information.
*/
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

/*
** CAPI3REF: Authorizer Action Codes {H12550} <H12500>
**
** The [sqlite3_set_authorizer()] interface registers a callback function
** that is invoked to authorize certain SQL statement actions.  The
** second parameter to the callback is an integer code that specifies
** what action is being authorized.  These are the integer action codes that
** the authorizer callback may be passed.
**
** These action code values signify what kind of operation is to be
** authorized.  The 3rd and 4th parameters to the authorization
** callback function will be parameters or NULL depending on which of these
** codes is used as the second parameter.  The 5th parameter to the
** authorizer callback is the name of the database ("main", "temp",
** etc.) if applicable.  The 6th parameter to the authorizer callback
** is the name of the inner-most trigger or view that is responsible for
** the access attempt or NULL if this access attempt is directly from
** top-level SQL code.
**
** Requirements:
** [H12551] [H12552] [H12553] [H12554]
*/
/******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
................................................................................
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
#define SQLITE_COPY                  0   /* No longer used */

/*
** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400>
** EXPERIMENTAL
**
** These routines register callback functions that can be used for
** tracing and profiling the execution of SQL statements.
**
** The callback function registered by sqlite3_trace() is invoked at
** various times when an SQL statement is being run by [sqlite3_step()].
** The callback returns a UTF-8 rendering of the SQL statement text
** as the statement first begins executing.  Additional callbacks occur

** as each triggered subprogram is entered.  The callbacks for triggers
** contain a UTF-8 SQL comment that identifies the trigger.
**
** The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.
**
** Requirements:
** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289]
** [H12290]
*/
SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

/*
** CAPI3REF: Query Progress Callbacks {H12910} <S60400>
**
** This routine configures a callback function - the
** progress callback - that is invoked periodically during long
** running calls to [sqlite3_exec()], [sqlite3_step()] and
** [sqlite3_get_table()].  An example use for this
** interface is to keep a GUI updated during a large query.
**
** If the progress callback returns non-zero, the operation is
** interrupted.  This feature can be used to implement a
** "Cancel" button on a GUI progress dialog box.
**
** The progress handler must not do anything that will modify
** the database connection that invoked the progress handler.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** Requirements:
** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918]
**
*/
void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

/*
** CAPI3REF: Opening A New Database Connection {H12700} <S40200>
**
** These routines open an SQLite database file whose name is given by the
** filename argument. The filename argument is interpreted as UTF-8 for
** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
** order for sqlite3_open16(). A [database connection] handle is usually
** returned in *ppDb, even if an error occurs.  The only exception is that
** if SQLite is unable to allocate memory to hold the [sqlite3] object,
** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
** object. If the database is opened (and/or created) successfully, then
** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.  The
** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
** an English language description of the error.

**
** The default encoding for the database will be UTF-8 if
** sqlite3_open() or sqlite3_open_v2() is called and
** UTF-16 in the native byte order if sqlite3_open16() is used.
**
** Whether or not an error occurs when it is opened, resources
** associated with the [database connection] handle should be released by
** passing it to [sqlite3_close()] when it is no longer required.
**
** The sqlite3_open_v2() interface works like sqlite3_open()
** except that it accepts two additional parameters for additional control
** over the new database connection.  The flags parameter can take one of

** the following three values, optionally combined with the 
** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
** and/or [SQLITE_OPEN_PRIVATECACHE] flags:
**
** <dl>
** <dt>[SQLITE_OPEN_READONLY]</dt>
** <dd>The database is opened in read-only mode.  If the database does not
** already exist, an error is returned.</dd>
**
** <dt>[SQLITE_OPEN_READWRITE]</dt>
** <dd>The database is opened for reading and writing if possible, or reading
** only if the file is write protected by the operating system.  In either
** case the database must already exist, otherwise an error is returned.</dd>
**
** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
** <dd>The database is opened for reading and writing, and is creates it if
** it does not already exist. This is the behavior that is always used for
** sqlite3_open() and sqlite3_open16().</dd>
** </dl>
**
** If the 3rd parameter to sqlite3_open_v2() is not one of the
** combinations shown above or one of the combinations shown above combined
** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX],
** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_SHAREDCACHE] flags,
** then the behavior is undefined.
**
** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
** opens in the multi-thread [threading mode] as long as the single-thread
** mode has not been set at compile-time or start-time.  If the
** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
** in the serialized [threading mode] unless single-thread was
** previously selected at compile-time or start-time.
** The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
** eligible to use [shared cache mode], regardless of whether or not shared
** cache is enabled using [sqlite3_enable_shared_cache()].  The
** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
** participate in [shared cache mode] even if it is enabled.
**
** If the filename is ":memory:", then a private, temporary in-memory database
** is created for the connection.  This in-memory database will vanish when
** the database connection is closed.  Future versions of SQLite might
** make use of additional special filenames that begin with the ":" character.
** It is recommended that when a database filename actually does begin with
** a ":" character you should prefix the filename with a pathname such as
** "./" to avoid ambiguity.
**
** If the filename is an empty string, then a private, temporary
** on-disk database will be created.  This private database will be
** automatically deleted as soon as the database connection is closed.
**
** The fourth parameter to sqlite3_open_v2() is the name of the
** [sqlite3_vfs] object that defines the operating system interface that
** the new database connection should use.  If the fourth parameter is
** a NULL pointer then the default [sqlite3_vfs] object is used.
**
** <b>Note to Windows users:</b>  The encoding used for the filename argument
** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
** codepage is currently defined.  Filenames containing international
** characters must be converted to UTF-8 prior to passing them into
** sqlite3_open() or sqlite3_open_v2().
**
** Requirements:
** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711]
** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723]
*/
int sqlite3_open(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb          /* OUT: SQLite db handle */
);
int sqlite3_open16(
  const void *filename,   /* Database filename (UTF-16) */
................................................................................
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  int flags,              /* Flags */
  const char *zVfs        /* Name of VFS module to use */
);

/*
** CAPI3REF: Error Codes And Messages {H12800} <S60200>
**
** The sqlite3_errcode() interface returns the numeric [result code] or
** [extended result code] for the most recent failed sqlite3_* API call
** associated with a [database connection]. If a prior API call failed
** but the most recent API call succeeded, the return value from
** sqlite3_errcode() is undefined.  The sqlite3_extended_errcode()
** interface is the same except that it always returns the 
** [extended result code] even when extended result codes are
** disabled.
**
** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF-8 or UTF-16 respectively.
** Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these
** interfaces always report the most recent result.  To avoid
** this, each thread can obtain exclusive use of the [database connection] D
................................................................................
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
** all calls to the interfaces listed here are completed.
**
** If an interface fails with SQLITE_MISUSE, that means the interface
** was invoked incorrectly by the application.  In that case, the
** error code and message may or may not be set.
**
** Requirements:
** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809]
*/
int sqlite3_errcode(sqlite3 *db);
int sqlite3_extended_errcode(sqlite3 *db);
const char *sqlite3_errmsg(sqlite3*);
const void *sqlite3_errmsg16(sqlite3*);

/*
** CAPI3REF: SQL Statement Object {H13000} <H13010>
** KEYWORDS: {prepared statement} {prepared statements}
**
** An instance of this object represents a single SQL statement.
** This object is variously known as a "prepared statement" or a
** "compiled SQL statement" or simply as a "statement".
**
** The life of a statement object goes something like this:
................................................................................
**
** Refer to documentation on individual methods above for additional
** information.
*/
typedef struct sqlite3_stmt sqlite3_stmt;

/*
** CAPI3REF: Run-time Limits {H12760} <S20600>
**
** This interface allows the size of various constructs to be limited
** on a connection by connection basis.  The first parameter is the
** [database connection] whose limit is to be set or queried.  The
** second parameter is one of the [limit categories] that define a
** class of constructs to be size limited.  The third parameter is the
** new limit for that construct.  The function returns the old limit.
**
** If the new limit is a negative number, the limit is unchanged.
** For the limit category of SQLITE_LIMIT_XYZ there is a 
** [limits | hard upper bound]
** set by a compile-time C preprocessor macro named 
** [limits | SQLITE_MAX_XYZ].
** (The "_LIMIT_" in the name is changed to "_MAX_".)
** Attempts to increase a limit above its hard upper bound are
** silently truncated to the hard upper limit.
**
** Run time limits are intended for use in applications that manage
** both their own internal database and also databases that are controlled
** by untrusted external sources.  An example application might be a
** web browser that has its own databases for storing history and
** separate databases controlled by JavaScript applications downloaded
** off the Internet.  The internal databases can be given the
** large, default limits.  Databases managed by external sources can
** be given much smaller limits designed to prevent a denial of service
** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
** interface to further control untrusted SQL.  The size of the database
** created by an untrusted script can be contained using the
** [max_page_count] [PRAGMA].
**
** New run-time limit categories may be added in future releases.
**
** Requirements:
** [H12762] [H12766] [H12769]
*/
int sqlite3_limit(sqlite3*, int id, int newVal);

/*
** CAPI3REF: Run-Time Limit Categories {H12790} <H12760>
** KEYWORDS: {limit category} {*limit categories}
**
** These constants define various performance limits
** that can be lowered at run-time using [sqlite3_limit()].
** The synopsis of the meanings of the various limits is shown below.
** Additional information is available at [limits | Limits in SQLite].
**
** <dl>
** <dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any string or BLOB or table row.<dd>
**
** <dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_COLUMN</dt>
** <dd>The maximum number of columns in a table definition or in the
** result set of a [SELECT] or the maximum number of columns in an index
** or in an ORDER BY or GROUP BY clause.</dd>
**
** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
** <dd>The maximum depth of the parse tree on any expression.</dd>
**
** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
** <dd>The maximum number of terms in a compound SELECT statement.</dd>
**
** <dt>SQLITE_LIMIT_VDBE_OP</dt>
** <dd>The maximum number of instructions in a virtual machine program
** used to implement an SQL statement.</dd>
**
** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
** <dd>The maximum number of arguments on a function.</dd>
**
** <dt>SQLITE_LIMIT_ATTACHED</dt>
** <dd>The maximum number of [ATTACH | attached databases].</dd>
**
** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
** <dd>The maximum length of the pattern argument to the [LIKE] or
** [GLOB] operators.</dd>
**
** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
** <dd>The maximum number of variables in an SQL statement that can
** be bound.</dd>
**
** <dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
** <dd>The maximum depth of recursion for triggers.</dd>
** </dl>
*/
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
................................................................................
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10

/*
** CAPI3REF: Compiling An SQL Statement {H13010} <S10000>
** KEYWORDS: {SQL statement compiler}
**
** To execute an SQL query, it must first be compiled into a byte-code
** program using one of these routines.
**
** The first argument, "db", is a [database connection] obtained from a
** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
................................................................................
** [sqlite3_open16()].  The database connection must not have been closed.
**
** The second argument, "zSql", is the statement to be compiled, encoded
** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
** use UTF-16.
**
** If the nByte argument is less than zero, then zSql is read up to the
** first zero terminator. If nByte is non-negative, then it is the maximum
** number of  bytes read from zSql.  When nByte is non-negative, the
** zSql string ends at either the first '\000' or '\u0000' character or
** the nByte-th byte, whichever comes first. If the caller knows
** that the supplied string is nul-terminated, then there is a small
** performance advantage to be gained by passing an nByte parameter that
** is equal to the number of bytes in the input string <i>including</i>
** the nul-terminator bytes.
**
** If pzTail is not NULL then *pzTail is made to point to the first byte
** past the end of the first SQL statement in zSql.  These routines only
** compile the first statement in zSql, so *pzTail is left pointing to
** what remains uncompiled.
**
** *ppStmt is left pointing to a compiled [prepared statement] that can be
** executed using [sqlite3_step()].  If there is an error, *ppStmt is set
** to NULL.  If the input text contains no SQL (if the input is an empty
** string or a comment) then *ppStmt is set to NULL.
** The calling procedure is responsible for deleting the compiled
** SQL statement using [sqlite3_finalize()] after it has finished with it.
** ppStmt may not be NULL.
**

** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned.
**
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
** recommended for all new programs. The two older interfaces are retained
** for backwards compatibility, but their use is discouraged.
** In the "v2" interfaces, the prepared statement
** that is returned (the [sqlite3_stmt] object) contains a copy of the
** original SQL text. This causes the [sqlite3_step()] interface to
** behave differently in three ways:
**
** <ol>
** <li>
** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
** always used to do, [sqlite3_step()] will automatically recompile the SQL
** statement and try to run it again.  If the schema has changed in
** a way that makes the statement no longer valid, [sqlite3_step()] will still
** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is
** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the
** error go away.  Note: use [sqlite3_errmsg()] to find the text
** of the parsing error that results in an [SQLITE_SCHEMA] return.
** </li>
**
** <li>
** When an error occurs, [sqlite3_step()] will return one of the detailed
** [error codes] or [extended error codes].  The legacy behavior was that
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
** and you would have to make a second call to [sqlite3_reset()] in order
** to find the underlying cause of the problem. With the "v2" prepare
** interfaces, the underlying reason for the error is returned immediately.
** </li>
**
** <li>
** ^If the value of a [parameter | host parameter] in the WHERE clause might
** change the query plan for a statement, then the statement may be
** automatically recompiled (as if there had been a schema change) on the first 
** [sqlite3_step()] call following any change to the 
** [sqlite3_bind_text | bindings] of the [parameter]. 
** </li>
** </ol>
**
** Requirements:
** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021]
**
*/
int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
................................................................................
  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);

/*
** CAPI3REF: Retrieving Statement SQL {H13100} <H13000>
**
** This interface can be used to retrieve a saved copy of the original
** SQL text used to create a [prepared statement] if that statement was
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
**
** Requirements:
** [H13101] [H13102] [H13103]
*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200>
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**
** SQLite uses the sqlite3_value object to represent all values
** that can be stored in a database table. SQLite uses dynamic typing
** for the values it stores. Values stored in sqlite3_value objects
** can be integers, floating point values, strings, BLOBs, or NULL.
**
** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies
** whether or not it requires a protected sqlite3_value.
................................................................................
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
** then there is no distinction between protected and unprotected
** sqlite3_value objects and they can be used interchangeably.  However,
** for maximum code portability it is recommended that applications
** still make the distinction between between protected and unprotected
** sqlite3_value objects even when not strictly required.
**
** The sqlite3_value objects that are passed as parameters into the
** implementation of [application-defined SQL functions] are protected.
** The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used with
** [sqlite3_result_value()] and [sqlite3_bind_value()].
** The [sqlite3_value_blob | sqlite3_value_type()] family of
** interfaces require protected sqlite3_value objects.
*/
typedef struct Mem sqlite3_value;

/*
** CAPI3REF: SQL Function Context Object {H16001} <S20200>
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  A pointer to an sqlite3_context object
** is always first parameter to [application-defined SQL functions].
** The application-defined SQL function implementation will pass this
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
** and/or [sqlite3_set_auxdata()].
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300>
** KEYWORDS: {host parameter} {host parameters} {host parameter name}
** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
**
** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
** literals may be replaced by a [parameter] that matches one of following
** templates:
**
** <ul>
** <li>  ?
** <li>  ?NNN
** <li>  :VVV
** <li>  @VVV
** <li>  $VVV
** </ul>
**
** In the templates above, NNN represents an integer literal,
** and VVV represents an alphanumeric identifer.  The values of these
** parameters (also called "host parameter names" or "SQL parameters")
** can be set using the sqlite3_bind_*() routines defined here.
**
** The first argument to the sqlite3_bind_*() routines is always
** a pointer to the [sqlite3_stmt] object returned from
** [sqlite3_prepare_v2()] or its variants.
**
** The second argument is the index of the SQL parameter to be set.
** The leftmost SQL parameter has an index of 1.  When the same named
** SQL parameter is used more than once, second and subsequent
** occurrences have the same index as the first occurrence.
** The index for named parameters can be looked up using the
** [sqlite3_bind_parameter_index()] API if desired.  The index
** for "?NNN" parameters is the value of NNN.
** The NNN value must be between 1 and the [sqlite3_limit()]
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
**
** The third argument is the value to bind to the parameter.
**
** In those routines that have a fourth argument, its value is the
** number of bytes in the parameter.  To be clear: the value is the
** number of <u>bytes</u> in the value, not the number of characters.
** If the fourth parameter is negative, the length of the string is
** the number of bytes up to the first zero terminator.
**
** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
** string after SQLite has finished with it. If the fifth argument is
** the special value [SQLITE_STATIC], then SQLite assumes that the
** information is in static, unmanaged space and does not need to be freed.
** If the fifth argument has the value [SQLITE_TRANSIENT], then
** SQLite makes its own private copy of the data immediately, before
** the sqlite3_bind_*() routine returns.
**
** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
** is filled with zeroes.  A zeroblob uses a fixed amount of memory
** (just an integer to hold its size) while it is being processed.
** Zeroblobs are intended to serve as placeholders for BLOBs whose
** content is later written using
** [sqlite3_blob_open | incremental BLOB I/O] routines.
** A negative value for the zeroblob results in a zero-length BLOB.
**
** The sqlite3_bind_*() routines must be called after
** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
** before [sqlite3_step()].
** Bindings are not cleared by the [sqlite3_reset()] routine.
** Unbound parameters are interpreted as NULL.
**
** These routines return [SQLITE_OK] on success or an error code if
** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter
** index is out of range.  [SQLITE_NOMEM] is returned if malloc() fails.
** [SQLITE_MISUSE] might be returned if these routines are called on a
** virtual machine that is the wrong state or which has already been finalized.
** Detection of misuse is unreliable.  Applications should not depend
** on SQLITE_MISUSE returns.  SQLITE_MISUSE is intended to indicate a
** a logic error in the application.  Future versions of SQLite might
** panic rather than return SQLITE_MISUSE.
**
** See also: [sqlite3_bind_parameter_count()],
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
**
** Requirements:
** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527]
** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551]
**
*/
int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

/*
** CAPI3REF: Number Of SQL Parameters {H13600} <S70300>
**
** This routine can be used to find the number of [SQL parameters]
** in a [prepared statement].  SQL parameters are tokens of the
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
** placeholders for values that are [sqlite3_bind_blob | bound]
** to the parameters at a later time.
**
** This routine actually returns the index of the largest (rightmost)
** parameter. For all forms except ?NNN, this will correspond to the
** number of unique parameters.  If parameters of the ?NNN are used,
** there may be gaps in the list.
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_name()], and
** [sqlite3_bind_parameter_index()].
**
** Requirements:
** [H13601]
*/
int sqlite3_bind_parameter_count(sqlite3_stmt*);

/*
** CAPI3REF: Name Of A Host Parameter {H13620} <S70300>
**
** This routine returns a pointer to the name of the n-th
** [SQL parameter] in a [prepared statement].
** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
** respectively.
** In other words, the initial ":" or "$" or "@" or "?"
** is included as part of the name.
** Parameters of the form "?" without a following integer have no name
** and are also referred to as "anonymous parameters".
**
** The first host parameter has an index of 1, not 0.
**
** If the value n is out of range or if the n-th parameter is
** nameless, then NULL is returned.  The returned string is
** always in UTF-8 encoding even if the named parameter was
** originally specified as UTF-16 in [sqlite3_prepare16()] or
** [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].
**
** Requirements:
** [H13621]
*/
const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

/*
** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300>
**
** Return the index of an SQL parameter given its name.  The
** index value returned is suitable for use as the second
** parameter to [sqlite3_bind_blob|sqlite3_bind()].  A zero
** is returned if no matching parameter is found.  The parameter
** name must be given in UTF-8 even if the original statement
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].
**
** Requirements:
** [H13641]
*/
int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);

/*
** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300>
**
** Contrary to the intuition of many, [sqlite3_reset()] does not reset
** the [sqlite3_bind_blob | bindings] on a [prepared statement].
** Use this routine to reset all host parameters to NULL.
**
** Requirements:
** [H13661]
*/
int sqlite3_clear_bindings(sqlite3_stmt*);

/*
** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700>
**
** Return the number of columns in the result set returned by the
** [prepared statement]. This routine returns 0 if pStmt is an SQL
** statement that does not return data (for example an [UPDATE]).
**
** Requirements:
** [H13711]
*/
int sqlite3_column_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Column Names In A Result Set {H13720} <S10700>
**
** These routines return the name assigned to a particular column
** in the result set of a [SELECT] statement.  The sqlite3_column_name()
** interface returns a pointer to a zero-terminated UTF-8 string
** and sqlite3_column_name16() returns a pointer to a zero-terminated
** UTF-16 string.  The first parameter is the [prepared statement]
** that implements the [SELECT] statement. The second parameter is the
** column number.  The leftmost column is number 0.
**
** The returned string pointer is valid until either the [prepared statement]
** is destroyed by [sqlite3_finalize()] or until the next call to
** sqlite3_column_name() or sqlite3_column_name16() on the same column.
**
** If sqlite3_malloc() fails during the processing of either routine
** (for example during a conversion from UTF-8 to UTF-16) then a
** NULL pointer is returned.
**
** The name of a result column is the value of the "AS" clause for
** that column, if there is an AS clause.  If there is no AS clause
** then the name of the column is unspecified and may change from
** one release of SQLite to the next.
**
** Requirements:
** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727]
*/
const char *sqlite3_column_name(sqlite3_stmt*, int N);
const void *sqlite3_column_name16(sqlite3_stmt*, int N);

/*
** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700>
**
** These routines provide a means to determine what column of what

** table in which database a result of a [SELECT] statement comes from.
** The name of the database or table or column can be returned as
** either a UTF-8 or UTF-16 string.  The _database_ routines return
** the database name, the _table_ routines return the table name, and
** the origin_ routines return the column name.
** The returned string is valid until the [prepared statement] is destroyed
** using [sqlite3_finalize()] or until the same information is requested
** again in a different encoding.
**
** The names returned are the original un-aliased names of the
** database, table, and column.
**
** The first argument to the following calls is a [prepared statement].
** These functions return information about the Nth column returned by
** the statement, where N is the second function argument.

**
** If the Nth column returned by the statement is an expression or
** subquery and is not a column value, then all of these functions return
** NULL.  These routine might also return NULL if a memory allocation error
** occurs.  Otherwise, they return the name of the attached database, table
** and column that query result column was extracted from.
**
** As with all other SQLite APIs, those postfixed with "16" return
** UTF-16 encoded strings, the other functions return UTF-8. {END}
**
** These APIs are only available if the library was compiled with the
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
**
** {A13751}
** If two or more threads call one or more of these routines against the same
** prepared statement and column at the same time then the results are
** undefined.
**
** Requirements:
** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748]
**
** If two or more threads call one or more
** [sqlite3_column_database_name | column metadata interfaces]
** for the same [prepared statement] and result column
** at the same time then the results are undefined.
*/
const char *sqlite3_column_database_name(sqlite3_stmt*,int);
const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
const char *sqlite3_column_table_name(sqlite3_stmt*,int);
const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

/*
** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700>
**
** The first parameter is a [prepared statement].
** If this statement is a [SELECT] statement and the Nth column of the
** returned result set of that [SELECT] is a table column (not an
** expression or subquery) then the declared type of the table
** column is returned.  If the Nth column of the result set is an
** expression or subquery, then a NULL pointer is returned.
** The returned string is always UTF-8 encoded. {END}
**
** For example, given the database schema:
**
** CREATE TABLE t1(c1 VARIANT);
**
** and the following statement to be compiled:
**
** SELECT c1 + 1, c1 FROM t1;
**
** this routine would return the string "VARIANT" for the second result
** column (i==1), and a NULL pointer for the first result column (i==0).
**
** SQLite uses dynamic run-time typing.  So just because a column
** is declared to contain a particular type does not mean that the
** data stored in that column is of the declared type.  SQLite is
** strongly typed, but the typing is dynamic not static.  Type
** is associated with individual values, not with the containers
** used to hold those values.
**
** Requirements:
** [H13761] [H13762] [H13763]
*/
const char *sqlite3_column_decltype(sqlite3_stmt*,int);
const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

/*
** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000>
**
** After a [prepared statement] has been prepared using either
** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
** must be called one or more times to evaluate the statement.
**
** The details of the behavior of the sqlite3_step() interface depend
** on whether the statement was prepared using the newer "v2" interface
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
** new "v2" interface is recommended for new applications but the legacy
** interface will continue to be supported.
**
** In the legacy interface, the return value will be either [SQLITE_BUSY],
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
** With the "v2" interface, any of the other [result codes] or
** [extended result codes] might be returned as well.
**
** [SQLITE_BUSY] means that the database engine was unable to acquire the
** database locks it needs to do its job.  If the statement is a [COMMIT]
** or occurs outside of an explicit transaction, then you can retry the
** statement.  If the statement is not a [COMMIT] and occurs within a
** explicit transaction then you should rollback the transaction before
** continuing.
**
** [SQLITE_DONE] means that the statement has finished executing
** successfully.  sqlite3_step() should not be called again on this virtual
** machine without first calling [sqlite3_reset()] to reset the virtual
** machine back to its initial state.
**
** If the SQL statement being executed returns any data, then [SQLITE_ROW]
** is returned each time a new row of data is ready for processing by the
** caller. The values may be accessed using the [column access functions].
** sqlite3_step() is called again to retrieve the next row of data.
**
** [SQLITE_ERROR] means that a run-time error (such as a constraint
** violation) has occurred.  sqlite3_step() should not be called again on
** the VM. More information may be found by calling [sqlite3_errmsg()].
** With the legacy interface, a more specific error code (for example,
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
** can be obtained by calling [sqlite3_reset()] on the
** [prepared statement].  In the "v2" interface,
** the more specific error code is returned directly by sqlite3_step().
**
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
** Perhaps it was called on a [prepared statement] that has
** already been [sqlite3_finalize | finalized] or on one that had
** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
** be the case that the same database connection is being used by two or
................................................................................
** specific [error codes] that better describes the error.
** We admit that this is a goofy design.  The problem has been fixed
** with the "v2" interface.  If you prepare all of your SQL statements
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
** then the more specific [error codes] are returned directly
** by sqlite3_step().  The use of the "v2" interface is recommended.
**
** Requirements:
** [H13202] [H15304] [H15306] [H15308] [H15310]
*/
int sqlite3_step(sqlite3_stmt*);

/*
** CAPI3REF: Number of columns in a result set {H13770} <S10700>
**
** Returns the number of values in the current row of the result set.
**
** Requirements:
** [H13771] [H13772]
*/
int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120>
** KEYWORDS: SQLITE_TEXT
**
** {H10266} Every value in SQLite has one of five fundamental datatypes:
**
** <ul>
** <li> 64-bit signed integer
** <li> 64-bit IEEE floating point number
** <li> string
** <li> BLOB
** <li> NULL
** </ul> {END}
**
** These constants are codes for each of those types.
**
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
** for a completely different meaning.  Software that links against both
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
** SQLITE_TEXT.
................................................................................
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3

/*
** CAPI3REF: Result Values From A Query {H13800} <S10700>
** KEYWORDS: {column access functions}
**
** These routines form the "result set query" interface.
**
** These routines return information about a single column of the current
** result row of a query.  In every case the first argument is a pointer
** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
** that was returned from [sqlite3_prepare_v2()] or one of its variants)
** and the second argument is the index of the column for which information
** should be returned.  The leftmost column of the result set has the index 0.
** The number of columns in the result can be determined using
** [sqlite3_column_count()].
**
** If the SQL statement does not currently point to a valid row, or if the
** column index is out of range, the result is undefined.
** These routines may only be called when the most recent call to
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
................................................................................
** If any of these routines are called after [sqlite3_reset()] or
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
** something other than [SQLITE_ROW], the results are undefined.
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
** are called from a different thread while any of these routines
** are pending, then the results are undefined.
**
** The sqlite3_column_type() routine returns the
** [SQLITE_INTEGER | datatype code] for the initial data type
** of the result column.  The returned value is one of [SQLITE_INTEGER],
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
** returned by sqlite3_column_type() is only meaningful if no type
** conversions have occurred as described below.  After a type conversion,
** the value returned by sqlite3_column_type() is undefined.  Future
** versions of SQLite may change the behavior of sqlite3_column_type()
** following a type conversion.
**
** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
** routine returns the number of bytes in that BLOB or string.
** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
** the string to UTF-8 and then returns the number of bytes.
** If the result is a numeric value then sqlite3_column_bytes() uses
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
** the number of bytes in that string.
** The value returned does not include the zero terminator at the end
** of the string.  For clarity: the value returned is the number of
** bytes in the string, not the number of characters.
**
** Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
** even empty strings, are always zero terminated.  The return
** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary
** pointer, possibly even a NULL pointer.
**
** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
** but leaves the result in UTF-16 in native byte order instead of UTF-8.
** The zero terminator is not included in this count.
**
** The object returned by [sqlite3_column_value()] is an
** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
** If the [unprotected sqlite3_value] object returned by
** [sqlite3_column_value()] is used in any other way, including calls
** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
** or [sqlite3_value_bytes()], then the behavior is undefined.
**
** These routines attempt to convert the value where appropriate.  For
** example, if the internal representation is FLOAT and a text result
** is requested, [sqlite3_snprintf()] is used internally to perform the
** conversion automatically.  The following table details the conversions
** that are applied:
**
** <blockquote>
** <table border="1">
** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
**
** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
................................................................................
** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
** <tr><td>  TEXT    <td>   BLOB    <td> No change
** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
** </table>
** </blockquote>
**
** The table above makes reference to standard C library functions atoi()
** and atof().  SQLite does not really use these functions.  It has its
** own equivalent internal routines.  The atoi() and atof() names are
** used in the table for brevity and because they are familiar to most
** C programmers.
**
** Note that when type conversions occur, pointers returned by prior
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
** sqlite3_column_text16() may be invalidated.
** Type conversions and pointer invalidations might occur
** in the following cases:
**
** <ul>
** <li> The initial content is a BLOB and sqlite3_column_text() or
**      sqlite3_column_text16() is called.  A zero-terminator might
**      need to be added to the string.</li>
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
**      sqlite3_column_text16() is called.  The content must be converted
**      to UTF-16.</li>
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
**      sqlite3_column_text() is called.  The content must be converted
**      to UTF-8.</li>
** </ul>
**
** Conversions between UTF-16be and UTF-16le are always done in place and do
** not invalidate a prior pointer, though of course the content of the buffer
** that the prior pointer points to will have been modified.  Other kinds
** of conversion are done in place when it is possible, but sometimes they
** are not possible and in those cases prior pointers are invalidated.
**
** The safest and easiest to remember policy is to invoke these routines
** in one of the following ways:
**
** <ul>
**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
** </ul>
**
** In other words, you should call sqlite3_column_text(),
** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
** into the desired format, then invoke sqlite3_column_bytes() or
** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
** to sqlite3_column_text() or sqlite3_column_blob() with calls to
** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
** with calls to sqlite3_column_bytes().
**
** The pointers returned are valid until a type conversion occurs as
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
** [sqlite3_finalize()] is called.  The memory space used to hold strings
** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
** [sqlite3_free()].
**
** If a memory allocation error occurs during the evaluation of any
** of these routines, a default value is returned.  The default value
** is either the integer 0, the floating point number 0.0, or a NULL
** pointer.  Subsequent calls to [sqlite3_errcode()] will return
** [SQLITE_NOMEM].
**
** Requirements:
** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824]
** [H13827] [H13830]
*/
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);
int sqlite3_column_int(sqlite3_stmt*, int iCol);
sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
int sqlite3_column_type(sqlite3_stmt*, int iCol);
sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

/*
** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100>
**
** The sqlite3_finalize() function is called to delete a [prepared statement].
** If the statement was executed successfully or not executed at all, then
** SQLITE_OK is returned. If execution of the statement failed then an
** [error code] or [extended error code] is returned.
**
** This routine can be called at any point during the execution of the
** [prepared statement].  If the virtual machine has not
** completed execution when this routine is called, that is like
** encountering an error or an [sqlite3_interrupt | interrupt].
** Incomplete updates may be rolled back and transactions canceled,
** depending on the circumstances, and the
** [error code] returned will be [SQLITE_ABORT].
**
** Requirements:
** [H11302] [H11304]
*/
int sqlite3_finalize(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300>
**
** The sqlite3_reset() function is called to reset a [prepared statement]
** object back to its initial state, ready to be re-executed.
** Any SQL statement variables that had values bound to them using
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
** Use [sqlite3_clear_bindings()] to reset the bindings.
**
** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S
**          back to the beginning of its program.
**
** {H11334} If the most recent call to [sqlite3_step(S)] for the
**          [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
**          or if [sqlite3_step(S)] has never before been called on S,
**          then [sqlite3_reset(S)] returns [SQLITE_OK].
**
** {H11336} If the most recent call to [sqlite3_step(S)] for the
**          [prepared statement] S indicated an error, then
**          [sqlite3_reset(S)] returns an appropriate [error code].
**
** {H11338} The [sqlite3_reset(S)] interface does not change the values
**          of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
*/
int sqlite3_reset(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200>
** KEYWORDS: {function creation routines}
** KEYWORDS: {application-defined SQL function}
** KEYWORDS: {application-defined SQL functions}
**
** These two functions (collectively known as "function creation routines")
** are used to add SQL functions or aggregates or to redefine the behavior
** of existing SQL functions or aggregates.  The only difference between the
** two is that the second parameter, the name of the (scalar) function or
** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16
** for sqlite3_create_function16().
**
** The first parameter is the [database connection] to which the SQL
** function is to be added.  If a single program uses more than one database
** connection internally, then SQL functions must be added individually to
** each database connection.
**
** The second parameter is the name of the SQL function to be created or
** redefined.  The length of the name is limited to 255 bytes, exclusive of
** the zero-terminator.  Note that the name length limit is in bytes, not
** characters.  Any attempt to create a function with a longer name
** will result in [SQLITE_ERROR] being returned.
**
** The third parameter (nArg)
** is the number of arguments that the SQL function or
** aggregate takes. If this parameter is -1, then the SQL function or
** aggregate may take any number of arguments between 0 and the limit
** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
** parameter is less than -1 or greater than 127 then the behavior is
** undefined.
**
** The fourth parameter, eTextRep, specifies what
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
** its parameters.  Any SQL function implementation should be able to work
** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
** more efficient with one encoding than another.  An application may
** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
** times with the same function but with different values of eTextRep.
** When multiple implementations of the same function are available, SQLite
** will pick the one that involves the least amount of data conversion.
** If there is only a single implementation which does not care what text
** encoding is used, then the fourth argument should be [SQLITE_ANY].
**
** The fifth parameter is an arbitrary pointer.  The implementation of the
** function can gain access to this pointer using [sqlite3_user_data()].
**
** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL function or
** aggregate. A scalar SQL function requires an implementation of the xFunc
** callback only, NULL pointers should be passed as the xStep and xFinal
** parameters. An aggregate SQL function requires an implementation of xStep
** and xFinal and NULL should be passed for xFunc. To delete an existing
** SQL function or aggregate, pass NULL for all three function callbacks.
**
** It is permitted to register multiple implementations of the same
** functions with the same name but with either differing numbers of
** arguments or differing preferred text encodings.  SQLite will use
** the implementation that most closely matches the way in which the
** SQL function is used.  A function implementation with a non-negative
** nArg parameter is a better match than a function implementation with
** a negative nArg.  A function where the preferred text encoding
** matches the database encoding is a better
** match than a function where the encoding is different.  
** A function where the encoding difference is between UTF16le and UTF16be
** is a closer match than a function where the encoding difference is
** between UTF8 and UTF16.
**
** Built-in functions may be overloaded by new application-defined functions.
** The first application-defined function with a given name overrides all
** built-in functions in the same [database connection] with the same name.
** Subsequent application-defined functions of the same name only override 
** prior application-defined functions that are an exact match for the
** number of parameters and preferred encoding.
**
** An application-defined function is permitted to call other
** SQLite interfaces.  However, such calls must not
** close the database connection nor finalize or reset the prepared
** statement in which the function is running.
**
** Requirements:
** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16127]
** [H16130] [H16133] [H16136] [H16139] [H16142]
*/
int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,
................................................................................
  void *pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);

/*
** CAPI3REF: Text Encodings {H10267} <S50200> <H16100>
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3
................................................................................
SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
SQLITE_DEPRECATED int sqlite3_global_recover(void);
SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
#endif

/*
** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200>
**
** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
................................................................................
** each parameter to the SQL function.  These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** These routines work just like the corresponding [column access functions]
** except that  these routines take a single [protected sqlite3_value] object
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
**
** The sqlite3_value_text16() interface extracts a UTF-16 string
** in the native byte-order of the host machine.  The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF-16 strings as big-endian and little-endian respectively.
**
** The sqlite3_value_numeric_type() interface attempts to apply
** numeric affinity to the value.  This means that an attempt is
** made to convert the value to an integer or floating point.  If
** such a conversion is possible without loss of information (in other
** words, if the value is a string that looks like a number)
** then the conversion is performed.  Otherwise no conversion occurs.
** The [SQLITE_INTEGER | datatype] after conversion is returned.
**
** Please pay particular attention to the fact that the pointer returned
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].
**
** These routines must be called from the same thread as
** the SQL function that supplied the [sqlite3_value*] parameters.
**
** Requirements:
** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124]
** [H15127] [H15130] [H15133] [H15136]
*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
................................................................................
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200>
**
** The implementation of aggregate SQL functions use this routine to allocate
** a structure for storing their state.
**
** The first time the sqlite3_aggregate_context() routine is called for a
** particular aggregate, SQLite allocates nBytes of memory, zeroes out that

** memory, and returns a pointer to it. On second and subsequent calls to
** sqlite3_aggregate_context() for the same aggregate function index,
** the same buffer is returned. The implementation of the aggregate can use
** the returned buffer to accumulate data.






**









** SQLite automatically frees the allocated buffer when the aggregate
** query concludes.

**
** The first parameter should be a copy of the
** [sqlite3_context | SQL function context] that is the first parameter
** to the callback routine that implements the aggregate function.

**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.
**
** Requirements:
** [H16211] [H16213] [H16215] [H16217]
*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** CAPI3REF: User Data For Functions {H16240} <S20200>
**
** The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function. {END}
**
** This routine must be called from the same thread in which
** the application-defined function is running.
**
** Requirements:
** [H16243]
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200>
**
** The sqlite3_context_db_handle() interface returns a copy of
** the pointer to the [database connection] (the 1st parameter)
** of the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.
**
** Requirements:
** [H16253]
*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data {H16270} <S20200>
**
** The following two functions may be used by scalar SQL functions to
** associate metadata with argument values. If the same value is passed to
** multiple invocations of the same SQL function during query execution, under
** some circumstances the associated metadata may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** metadata associated with the SQL value passed as the regular expression
** pattern.  The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**
** The sqlite3_get_auxdata() interface returns a pointer to the metadata
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function. If no metadata has been ever
** been set for the Nth argument of the function, or if the corresponding
** function parameter has changed since the meta-data was set,
** then sqlite3_get_auxdata() returns a NULL pointer.
**
** The sqlite3_set_auxdata() interface saves the metadata
** pointed to by its 3rd parameter as the metadata for the N-th
** argument of the application-defined function.  Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed.
** If it is not NULL, SQLite will invoke the destructor
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the metadata when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first.
**
** SQLite is free to call the destructor and drop metadata on any
** parameter of any function at any time.  The only guarantee is that
** the destructor will be called before the metadata is dropped.
**
** In practice, metadata is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
**
** These routines must be called from the same thread in which
** the SQL function is running.
**
** Requirements:
** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279]
*/
void *sqlite3_get_auxdata(sqlite3_context*, int N);
void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100>
**
** These are special values for the destructor that is passed in as the
** final argument to routines like [sqlite3_result_blob()].  If the destructor
** argument is SQLITE_STATIC, it means that the content pointer is constant
** and will never change.  It does not need to be destroyed.  The
** SQLITE_TRANSIENT value means that the content will likely change in
** the near future and that SQLite should make its own private copy of
** the content before returning.
**
** The typedef is necessary to work around problems in certain
** C++ compilers.  See ticket #2191.
*/
typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

/*
** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200>
**
** These routines are used by the xFunc or xFinal callbacks that
** implement SQL functions and aggregates.  See
** [sqlite3_create_function()] and [sqlite3_create_function16()]
** for additional information.
**
** These functions work very much like the [parameter binding] family of
** functions used to bind values to host parameters in prepared statements.
** Refer to the [SQL parameter] documentation for additional information.
**
** The sqlite3_result_blob() interface sets the result from
** an application-defined function to be the BLOB whose content is pointed
** to by the second parameter and which is N bytes long where N is the
** third parameter.
**
** The sqlite3_result_zeroblob() interfaces set the result of
** the application-defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** The sqlite3_result_double() interface sets the result from
** an application-defined function to be a floating point value specified
** by its 2nd argument.
**
** The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** SQLite uses the string pointed to by the
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
** as the text of an error message.  SQLite interprets the error
** message string from sqlite3_result_error() as UTF-8. SQLite
** interprets the string from sqlite3_result_error16() as UTF-16 in native
** byte order.  If the third parameter to sqlite3_result_error()
** or sqlite3_result_error16() is negative then SQLite takes as the error
** message all text up through the first zero character.
** If the third parameter to sqlite3_result_error() or
** sqlite3_result_error16() is non-negative then SQLite takes that many
** bytes (not characters) from the 2nd parameter as the error message.
** The sqlite3_result_error() and sqlite3_result_error16()
** routines make a private copy of the error message text before
** they return.  Hence, the calling function can deallocate or
** modify the text after they return without harm.
** The sqlite3_result_error_code() function changes the error code
** returned by SQLite as a result of an error in a function.  By default,
** the error code is SQLITE_ERROR.  A subsequent call to sqlite3_result_error()
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
**
** The sqlite3_result_toobig() interface causes SQLite to throw an error
** indicating that a string or BLOB is to long to represent.
**
** The sqlite3_result_nomem() interface causes SQLite to throw an error
** indicating that a memory allocation failed.
**
** The sqlite3_result_int() interface sets the return value
** of the application-defined function to be the 32-bit signed integer
** value given in the 2nd argument.
** The sqlite3_result_int64() interface sets the return value
** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** The sqlite3_result_text(), sqlite3_result_text16(),
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter
** through the first zero character.
** If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text
** pointed to by the 2nd parameter are taken as the application-defined
** function result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
** function as the destructor on the text or BLOB result when it has
** finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces or to
** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
** assumes that the text or BLOB result is in constant space and does not
** copy the content of the parameter nor call a destructor on the content
** when it has finished using that result.
** If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the
** [unprotected sqlite3_value] object specified by the 2nd parameter.  The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that the [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread
** than the one containing the application-defined function that received
** the [sqlite3_context] pointer, the results are undefined.
**
** Requirements:
** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424]
** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448]
** [H16451] [H16454] [H16457] [H16460] [H16463]
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
................................................................................
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*
** CAPI3REF: Define New Collating Sequences {H16600} <S20300>
**
** These functions are used to add new collation sequences to the
** [database connection] specified as the first argument.
**
** The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). In all cases
** the name is passed as the second function argument.
**
** The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian, or UTF-16 big-endian, respectively. The
** third argument might also be [SQLITE_UTF16] to indicate that the routine
** expects pointers to be UTF-16 strings in the native byte order, or the
** argument can be [SQLITE_UTF16_ALIGNED] if the
** the routine expects pointers to 16-bit word aligned strings
** of UTF-16 in the native byte order.
**
** A pointer to the user supplied routine must be passed as the fifth
** argument.  If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** Each time the application supplied function is invoked, it is passed
** as its first parameter a copy of the void* passed as the fourth argument
** to sqlite3_create_collation() or sqlite3_create_collation16().
**
** The remaining arguments to the application-supplied routine are two strings,
** each represented by a (length, data) pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered. {END}  The application defined collation routine should
** return negative, zero or positive if the first string is less than,
** equal to, or greater than the second string. i.e. (STRING1 - STRING2).
**
** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** except that it takes an extra argument which is a destructor for
** the collation.  The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** Collations are destroyed when they are overridden by later calls to the
** collation creation functions or when the [database connection] is closed
** using [sqlite3_close()].
**
** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
**
** Requirements:
** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621]
** [H16624] [H16627] [H16630]
*/
int sqlite3_create_collation(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
................................................................................
  const void *zName,
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);

/*
** CAPI3REF: Collation Needed Callbacks {H16700} <S20300>
**
** To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** [database connection] to be called whenever an undefined collation
** sequence is required.
**
** If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used,
** the names are passed as UTF-16 in machine native byte order.
** A call to either function replaces any existing callback.
**
** When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16().  The second argument is the database
** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
** sequence function required.  The fourth parameter is the name of the
** required collation sequence.
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].
**
** Requirements:
** [H16702] [H16704] [H16706]
*/
int sqlite3_collation_needed(
  sqlite3*, 
  void*, 
  void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(
................................................................................
*/
int sqlite3_rekey(
  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410>
**
** The sqlite3_sleep() function causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** If the operating system does not support sleep requests with
** millisecond time resolution, then the time will be rounded up to
** the nearest second. The number of milliseconds of sleep actually
** requested from the operating system is returned.
**
** SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.
**
** Requirements: [H10533] [H10536]
*/
int sqlite3_sleep(int);

/*
** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000>
**
** If this global variable is made to point to a string which is
** the name of a folder (a.k.a. directory), then all temporary files

** created by SQLite will be placed in that directory.  If this variable
** is a NULL pointer, then SQLite performs a search for an appropriate
** temporary file directory.
**
** It is not safe to read or modify this variable in more than one
** thread at a time.  It is not safe to read or modify this variable
** if a [database connection] is being used at the same time in a separate
** thread.
** It is intended that this variable be set once
** as part of process initialization and before any SQLite interface
** routines have been called and that this variable remain unchanged
** thereafter.
**
** The [temp_store_directory pragma] may modify this variable and cause
** it to point to memory obtained from [sqlite3_malloc].  Furthermore,
** the [temp_store_directory pragma] always assumes that any string
** that this variable points to is held in memory obtained from 
** [sqlite3_malloc] and the pragma may attempt to free that memory
** using [sqlite3_free].
** Hence, if this variable is modified directly, either it should be
** made NULL or made to point to memory obtained from [sqlite3_malloc]
** or else the use of the [temp_store_directory pragma] should be avoided.
*/
SQLITE_EXTERN char *sqlite3_temp_directory;

/*
** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200>
** KEYWORDS: {autocommit mode}
**
** The sqlite3_get_autocommit() interface returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively.  Autocommit mode is on by default.
** Autocommit mode is disabled by a [BEGIN] statement.
** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
**
** If certain kinds of errors occur on a statement within a multi-statement
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  The only way to
** find out whether SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** If another thread changes the autocommit status of the database
** connection while this routine is running, then the return value
** is undefined.
**
** Requirements: [H12931] [H12932] [H12933] [H12934]
*/
int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600>
**
** The sqlite3_db_handle interface returns the [database connection] handle
** to which a [prepared statement] belongs.  The [database connection]
** returned by sqlite3_db_handle is the same [database connection] that was the first argument

** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
** create the statement in the first place.
**
** Requirements: [H13123]
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

/*
** CAPI3REF: Find the next prepared statement {H13140} <S60600>
**
** This interface returns a pointer to the next [prepared statement] after
** pStmt associated with the [database connection] pDb.  If pStmt is NULL
** then this interface returns a pointer to the first prepared statement
** associated with the database connection pDb.  If no prepared statement
** satisfies the conditions of this routine, it returns NULL.
**
** The [database connection] pointer D in a call to
** [sqlite3_next_stmt(D,S)] must refer to an open database
** connection and in particular must not be a NULL pointer.
**
** Requirements: [H13143] [H13146] [H13149] [H13152]
*/
sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);

/*
** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400>
**
** The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is [COMMIT | committed].
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
** Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** The pArg argument is passed through to the callback.
** If the callback on a commit hook function returns non-zero,
** then the commit is converted into a rollback.
**
** If another function was previously registered, its
** pArg value is returned.  Otherwise NULL is returned.


**
** The callback implementation must not do anything that will modify
** the database connection that invoked the callback.  Any actions
** to modify the database connection must be deferred until after the
** completion of the [sqlite3_step()] call that triggered the commit
** or rollback hook in the first place.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** Registering a NULL function disables the callback.
**
** When the commit hook callback routine returns zero, the [COMMIT]
** operation is allowed to continue normally.  If the commit hook
** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
** The rollback hook is invoked on a rollback that results from a commit
** hook returning non-zero, just as it would be with any other rollback.
**
** For the purposes of this API, a transaction is said to have been
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.
** <todo> Check on this </todo>
**
** See also the [sqlite3_update_hook()] interface.
**
** Requirements:
** [H12951] [H12952] [H12953] [H12954] [H12955]
** [H12961] [H12962] [H12963] [H12964]
*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400>
**
** The sqlite3_update_hook() interface registers a callback function
** with the [database connection] identified by the first argument
** to be invoked whenever a row is updated, inserted or deleted.
** Any callback set by a previous call to this function
** for the same database connection is overridden.
**
** The second argument is a pointer to the function to invoke when a
** row is updated, inserted or deleted.
** The first argument to the callback is a copy of the third argument
** to sqlite3_update_hook().
** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
** or [SQLITE_UPDATE], depending on the operation that caused the callback
** to be invoked.
** The third and fourth arguments to the callback contain pointers to the
** database and table name containing the affected row.
** The final callback parameter is the [rowid] of the row.
** In the case of an update, this is the [rowid] after the update takes place.
**
** The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).
**
** In the current implementation, the update hook
** is not invoked when duplication rows are deleted because of an
** [ON CONFLICT | ON CONFLICT REPLACE] clause.  Nor is the update hook
** invoked when rows are deleted using the [truncate optimization].
** The exceptions defined in this paragraph might change in a future
** release of SQLite.
**
** The update hook implementation must not do anything that will modify
** the database connection that invoked the update hook.  Any actions
** to modify the database connection must be deferred until after the
** completion of the [sqlite3_step()] call that triggered the update hook.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** If another function was previously registered, its pArg value
** is returned.  Otherwise NULL is returned.


**
** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
** interfaces.
**
** Requirements:
** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986]
*/
void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);

/*
** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900>
** KEYWORDS: {shared cache}
**
** This routine enables or disables the sharing of the database cache
** and schema data structures between [database connection | connections]
** to the same database. Sharing is enabled if the argument is true
** and disabled if the argument is false.
**
** Cache sharing is enabled and disabled for an entire process.
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
** sharing was enabled or disabled for each thread separately.
**
** The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.
**
** Virtual tables cannot be used with a shared cache.  When shared
** cache is enabled, the [sqlite3_create_module()] API used to register
** virtual tables will always return an error.
**
** This routine returns [SQLITE_OK] if shared cache was enabled or disabled
** successfully.  An [error code] is returned otherwise.
**
** Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** See Also:  [SQLite Shared-Cache Mode]
**
** Requirements: [H10331] [H10336] [H10337] [H10339]
*/
int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220>
**
** The sqlite3_release_memory() interface attempts to free N bytes
** of heap memory by deallocating non-essential memory allocations
** held by the database library. {END}  Memory used to cache database
** pages to improve performance is an example of non-essential memory.
** sqlite3_release_memory() returns the number of bytes actually freed,
** which might be more or less than the amount requested.
**
** Requirements: [H17341] [H17342]
*/
int sqlite3_release_memory(int);

/*
** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220>
**
** The sqlite3_soft_heap_limit() interface places a "soft" limit
** on the amount of heap memory that may be allocated by SQLite.
** If an internal allocation is requested that would exceed the
** soft heap limit, [sqlite3_release_memory()] is invoked one or
** more times to free up some space before the allocation is performed.
**
** The limit is called "soft", because if [sqlite3_release_memory()]
** cannot free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** The default value for the soft heap limit is zero.
**
** SQLite makes a best effort to honor the soft heap limit.
** But if the soft heap limit cannot be honored, execution will
** continue without error or notification.  This is why the limit is
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.
**
** Requirements:
** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358]
*/
void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300>
**
** This routine returns metadata about a specific column of a specific
** database table accessible using the [database connection] handle
** passed as the first function argument.
**
** The column is identified by the second, third and fourth parameters to
** this function. The second parameter is either the name of the database
** (i.e. "main", "temp" or an attached database) containing the specified
** table or NULL. If it is NULL, then all attached databases are searched
** for the table using the same algorithm used by the database engine to
** resolve unqualified table references.
**
** The third and fourth parameters to this function are the table and column
** name of the desired column, respectively. Neither of these parameters
** may be NULL.
**
** Metadata is returned by writing to the memory locations passed as the 5th
** and subsequent parameters to this function. Any of these arguments may be
** NULL, in which case the corresponding element of metadata is omitted.
**
** <blockquote>
** <table border="1">
** <tr><th> Parameter <th> Output<br>Type <th>  Description
**
** <tr><td> 5th <td> const char* <td> Data type
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
** </table>
** </blockquote>
**
** The memory pointed to by the character pointers returned for the
** declaration type and collation sequence is valid only until the next
** call to any SQLite API function.
**
** If the specified table is actually a view, an [error code] is returned.
**
** If the specified column is "rowid", "oid" or "_rowid_" and an
** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
** parameters are set for the explicitly declared column. If there is no
** explicitly declared [INTEGER PRIMARY KEY] column, then the output
** parameters are set as follows:
**
** <pre>
**     data type: "INTEGER"
**     collation sequence: "BINARY"
**     not null: 0
**     primary key: 1
**     auto increment: 0
** </pre>
**
** This function may load one or more schemas from database files. If an
** error occurs during this process, or if the requested table or column
** cannot be found, an [error code] is returned and an error message left
** in the [database connection] (to be retrieved using sqlite3_errmsg()).
**
** This API is only available if the library was compiled with the
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
*/
int sqlite3_table_column_metadata(
  sqlite3 *db,                /* Connection handle */
  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
................................................................................
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension {H12600} <S20500>
**
** This interface loads an SQLite extension library from the named file.
**
** {H12601} The sqlite3_load_extension() interface attempts to load an
**          SQLite extension library contained in the file zFile.
**
** {H12602} The entry point is zProc.
**
** {H12603} zProc may be 0, in which case the name of the entry point
**          defaults to "sqlite3_extension_init".
**
** {H12604} The sqlite3_load_extension() interface shall return
**          [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
**
** {H12605} If an error occurs and pzErrMsg is not 0, then the
**          [sqlite3_load_extension()] interface shall attempt to
**          fill *pzErrMsg with error message text stored in memory
**          obtained from [sqlite3_malloc()]. {END}  The calling function
**          should free this memory by calling [sqlite3_free()].
**
** {H12606} Extension loading must be enabled using
**          [sqlite3_enable_load_extension()] prior to calling this API,
**          otherwise an error will be returned.
**
** See also the [load_extension() SQL function].
*/
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
);

/*
** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500>
**
** So as not to open security holes in older applications that are
** unprepared to deal with extension loading, and as a means of disabling
** extension loading while evaluating user-entered SQL, the following API
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
**
** Extension loading is off by default. See ticket #1863.
**
** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1
**          to turn extension loading on and call it with onoff==0 to turn
**          it back off again.
**
** {H12622} Extension loading is off by default.
*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

/*
** CAPI3REF: Automatically Load An Extensions {H12640} <S20500>
**
** This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new [database connections]. {END}
**
** This routine stores a pointer to the extension in an array that is
** obtained from [sqlite3_malloc()].  If you run a memory leak checker
** on your program and it reports a leak because of this array, invoke
** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory.
**
** {H12641} This function registers an extension entry point that is
**          automatically invoked whenever a new [database connection]
**          is opened using [sqlite3_open()], [sqlite3_open16()],
**          or [sqlite3_open_v2()].
**
** {H12642} Duplicate extensions are detected so calling this routine
**          multiple times with the same extension is harmless.
**
** {H12643} This routine stores a pointer to the extension in an array
**          that is obtained from [sqlite3_malloc()].
**
** {H12644} Automatic extensions apply across all threads.
*/
int sqlite3_auto_extension(void (*xEntryPoint)(void));

/*
** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500>
**
** This function disables all previously registered automatic
** extensions. {END}  It undoes the effect of all prior
** [sqlite3_auto_extension()] calls.
**
** {H12661} This function disables all previously registered
**          automatic extensions.
**
** {H12662} This function disables automatic extensions in all threads.
*/
void sqlite3_reset_auto_extension(void);

/*
****** EXPERIMENTAL - subject to change without notice **************
**
** The interface to the virtual-table mechanism is currently considered
................................................................................
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;

/*
** CAPI3REF: Virtual Table Object {H18000} <S20400>
** KEYWORDS: sqlite3_module {virtual table module}
** EXPERIMENTAL
**
** This structure, sometimes called a a "virtual table module", 
** defines the implementation of a [virtual tables].  
** This structure consists mostly of methods for the module.
**
** A virtual table module is created by filling in a persistent
** instance of this structure and passing a pointer to that instance
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
** The registration remains valid until it is replaced by a different
** module or until the [database connection] closes.  The content
** of this structure must not change while it is registered with
** any database connection.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,
................................................................................
  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);
  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*
** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400>
** KEYWORDS: sqlite3_index_info
** EXPERIMENTAL
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the [xBestIndex]
** method of a [virtual table module].  The fields under **Inputs** are the
** inputs to xBestIndex and are read-only.  xBestIndex inserts its
** results into the **Outputs** fields.
**
** The aConstraint[] array records WHERE clause constraints of the form:
**
** <pre>column OP expr</pre>
**
** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.  The particular operator is
** stored in aConstraint[].op.  The index of the column is stored in
** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
** expr on the right-hand side can be evaluated (and thus the constraint
** is usable) and false if it cannot.
**
** The optimizer automatically inverts terms of the form "expr OP column"
** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** The aConstraint[] array only reports WHERE clause terms in the correct
** form that refer to the particular virtual table being queried.
**
** Information about the ORDER BY clause is stored in aOrderBy[].
** Each term of aOrderBy records a column of the ORDER BY clause.
**
** The [xBestIndex] method must fill aConstraintUsage[] with information
** about what parameters to pass to xFilter.  If argvIndex>0 then
** the right-hand side of the corresponding aConstraint[] is evaluated
** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
** is true, then the constraint is assumed to be fully handled by the
** virtual table and is not checked again by SQLite.
**
** The idxNum and idxPtr values are recorded and passed into the
** [xFilter] method.
** [sqlite3_free()] is used to free idxPtr if and only iff
** needToFreeIdxPtr is true.
**
** The orderByConsumed means that output from [xFilter]/[xNext] will occur in
** the correct order to satisfy the ORDER BY clause so that no separate
** sorting step is required.
**
** The estimatedCost value is an estimate of the cost of doing the
** particular lookup.  A full scan of a table with N entries should have
** a cost of N.  A binary search of a table of N entries should have a
** cost of approximately log(N).
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
................................................................................
#define SQLITE_INDEX_CONSTRAINT_GT    4
#define SQLITE_INDEX_CONSTRAINT_LE    8
#define SQLITE_INDEX_CONSTRAINT_LT    16
#define SQLITE_INDEX_CONSTRAINT_GE    32
#define SQLITE_INDEX_CONSTRAINT_MATCH 64

/*
** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400>
** EXPERIMENTAL
**
** This routine is used to register a new [virtual table module] name.
** Module names must be registered before
** creating a new [virtual table] using the module, or before using a
** preexisting [virtual table] for the module.
**
** The module name is registered on the [database connection] specified
** by the first parameter.  The name of the module is given by the 
** second parameter.  The third parameter is a pointer to
** the implementation of the [virtual table module].   The fourth
** parameter is an arbitrary client data pointer that is passed through
** into the [xCreate] and [xConnect] methods of the virtual table module
** when a new virtual table is be being created or reinitialized.
**
** This interface has exactly the same effect as calling
** [sqlite3_create_module_v2()] with a NULL client data destructor.





*/
SQLITE_EXPERIMENTAL int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *p,   /* Methods for the module */
  void *pClientData          /* Client data for xCreate/xConnect */
);

/*
** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400>
** EXPERIMENTAL
**
** This routine is identical to the [sqlite3_create_module()] method,
** except that it has an extra parameter to specify 
** a destructor function for the client data pointer.  SQLite will
** invoke the destructor function (if it is not NULL) when SQLite
** no longer needs the pClientData pointer.  
*/
SQLITE_EXPERIMENTAL int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *p,   /* Methods for the module */
  void *pClientData,         /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** CAPI3REF: Virtual Table Instance Object {H18010} <S20400>
** KEYWORDS: sqlite3_vtab
** EXPERIMENTAL
**
** Every [virtual table module] implementation uses a subclass
** of the following structure to describe a particular instance
** of the [virtual table].  Each subclass will
** be tailored to the specific needs of the module implementation.
** The purpose of this superclass is to define certain fields that are
** common to all module implementations.
**
** Virtual tables methods can set an error message by assigning a
** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
** take care that any prior string is freed by a call to [sqlite3_free()]
** prior to assigning a new string to zErrMsg.  After the error message
** is delivered up to the client application, the string will be automatically
** freed by sqlite3_free() and the zErrMsg field will be zeroed.
*/
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* NO LONGER USED */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Virtual Table Cursor Object  {H18020} <S20400>
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
** EXPERIMENTAL
**
** Every [virtual table module] implementation uses a subclass of the
** following structure to describe cursors that point into the
** [virtual table] and are used
** to loop through the virtual table.  Cursors are created using the
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
** by the [sqlite3_module.xClose | xClose] method.  Cussors are used
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
** of the module.  Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400>
** EXPERIMENTAL
**
** The [xCreate] and [xConnect] methods of a
** [virtual table module] call this interface
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL);

/*
** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400>
** EXPERIMENTAL
**
** Virtual tables can provide alternative implementations of functions
** using the [xFindFunction] method of the [virtual table module].  
** But global versions of those functions
** must exist in order to be overloaded.
**
** This API makes sure a global version of a function with a particular
** name and number of parameters exists.  If no such function exists
** before this API is called, a new function is created.  The implementation
** of the new function always causes an exception to be thrown.  So
** the new function is not good for anything by itself.  Its only
** purpose is to be a placeholder function that can be overloaded
** by a [virtual table].
*/
SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);

................................................................................
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230>
** KEYWORDS: {BLOB handle} {BLOB handles}
**
** An instance of this object represents an open BLOB on which
** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
** Objects of this type are created by [sqlite3_blob_open()]
** and destroyed by [sqlite3_blob_close()].
** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the BLOB.
** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230>
**
** This interfaces opens a [BLOB handle | handle] to the BLOB located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same BLOB that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
** </pre> {END}
**
** If the flags parameter is non-zero, then the BLOB is opened for read
** and write access. If it is zero, the BLOB is opened for read access.
** It is not possible to open a column that is part of an index or primary 
** key for writing. ^If [foreign key constraints] are enabled, it is 
** not possible to open a column that is part of a [child key] for writing.
**
** Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** is assigned when the database is connected using [ATTACH].
** For the main database file, the database name is "main".
** For TEMP tables, the database name is "temp".
**
** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
** to be a null pointer.
** This function sets the [database connection] error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
** functions.  Note that the *ppBlob variable is always initialized in a
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
** regardless of the success or failure of this routine.
**
** If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.
** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
** a expired BLOB handle fail with an return code of [SQLITE_ABORT].
** Changes written into a BLOB prior to the BLOB expiring are not
** rollback by the expiration of the BLOB.  Such changes will eventually
** commit if the transaction continues to completion.
**
** Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a
** blob.
**
** The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
** and the built-in [zeroblob] SQL function can be used, if desired,
** to create an empty, zero-filled blob in which to read or write using
** this interface.
**
** To avoid a resource leak, every open [BLOB handle] should eventually
** be released by a call to [sqlite3_blob_close()].
**
** Requirements:
** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824]
*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF: Close A BLOB Handle {H17830} <S30230>
**
** Closes an open [BLOB handle].
**
** Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in [autocommit mode].
** If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit.
**
** Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  Any errors that occur during
** closing are reported as a non-zero return value.
**
** The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.
**
** Calling this routine with a null pointer (which as would be returned
** by failed call to [sqlite3_blob_open()]) is a harmless no-op.
**
** Requirements:
** [H17833] [H17836] [H17839]
*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230>
**
** Returns the size in bytes of the BLOB accessible via the 
** successfully opened [BLOB handle] in its only argument.  The
** incremental blob I/O routines can only read or overwriting existing
** blob content; they cannot change the size of a blob.
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** Requirements:
** [H17843]
*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230>
**
** This function is used to read data from an open [BLOB handle] into a
** caller-supplied buffer. N bytes of data are copied into buffer Z
** from the open BLOB, starting at offset iOffset.
**
** If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is read.  If N or iOffset is
** less than zero, [SQLITE_ERROR] is returned and no data is read.
** The size of the blob (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.
**
** An attempt to read from an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].
**
** On success, SQLITE_OK is returned.
** Otherwise, an [error code] or an [extended error code] is returned.
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_write()].
**
** Requirements:
** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868]
*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230>
**
** This function is used to write data into an open [BLOB handle] from a
** caller-supplied buffer. N bytes of data are copied from the buffer Z
** into the open BLOB, starting at offset iOffset.
**
** If the [BLOB handle] passed as the first argument was not opened for
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
** this function returns [SQLITE_READONLY].
**
** This function may only modify the contents of the BLOB; it is
** not possible to increase the size of a BLOB using this API.
** If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is written.  If N is
** less than zero [SQLITE_ERROR] is returned and no data is written.
** The size of the BLOB (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.
**
** An attempt to write to an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].  Writes to the BLOB that occurred
** before the [BLOB handle] expired are not rolled back by the
** expiration of the handle, though of course those changes might
** have been overwritten by the statement that expired the BLOB handle
** or by other independent statements.
**
** On success, SQLITE_OK is returned.
** Otherwise, an  [error code] or an [extended error code] is returned.
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_read()].
**
** Requirements:
** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885]
** [H17888]
*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF: Virtual File System Objects {H11200} <S20100>
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most SQLite builds come with a
** single default VFS that is appropriate for the host computer.
** New VFSes can be registered and existing VFSes can be unregistered.
** The following interfaces are provided.
**
** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
** Names are case sensitive.
** Names are zero-terminated UTF-8 strings.
** If there is no match, a NULL pointer is returned.
** If zVfsName is NULL then the default VFS is returned.
**
** New VFSes are registered with sqlite3_vfs_register().
** Each new VFS becomes the default VFS if the makeDflt flag is set.
** The same VFS can be registered multiple times without injury.
** To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set.  If two different VFSes with the
** same name are registered, the behavior is undefined.  If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
**
** Unregister a VFS with the sqlite3_vfs_unregister() interface.
** If the default VFS is unregistered, another VFS is chosen as
** the default.  The choice for the new VFS is arbitrary.
**
** Requirements:
** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218]
*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes {H17000} <S20000>
**
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  The following
** implementations are available in the SQLite core:
**
** <ul>
** <li>   SQLITE_MUTEX_OS2
** <li>   SQLITE_MUTEX_PTHREAD
** <li>   SQLITE_MUTEX_W32
** <li>   SQLITE_MUTEX_NOOP
** </ul>
**
** The SQLITE_MUTEX_NOOP implementation is a set of routines
** that does no real locking and is appropriate for use in
** a single-threaded application.  The SQLITE_MUTEX_OS2,
** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
** are appropriate for use on OS/2, Unix, and Windows.
**
** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. In this case the
** application must supply a custom mutex implementation using the
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
** before calling sqlite3_initialize() or any other public sqlite3_
** function that calls sqlite3_initialize().
**
** {H17011} The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. {H17012} If it returns NULL
** that means that a mutex could not be allocated. {H17013} SQLite
** will unwind its stack and return an error. {H17014} The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** </ul>
**

** {H17015} The first two constants cause sqlite3_mutex_alloc() to create
** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END}
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  {H17016} But SQLite will only request a recursive mutex in
** cases where it really needs one.  {END} If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return

** a pointer to a static preexisting mutex. {END}  Six static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  {H17034} But for the static
** mutex types, the same mutex is returned on every call that has
** the same type number.
**
** {H17019} The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every
** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in
** use when they are deallocated. {A17022} Attempting to deallocate a static
** mutex results in undefined behavior. {H17023} SQLite never deallocates
** a static mutex. {END}
**
** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex. {H17024} If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY. {H17025}  The sqlite3_mutex_try() interface returns [SQLITE_OK]
** upon successful entry.  {H17026} Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** {H17027} In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.  {A17028} If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** {H17029} SQLite will never exhibit
** such behavior in its own use of mutexes.
**
** Some systems (for example, Windows 95) do not support the operation
** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
** will always return SQLITE_BUSY.  {H17030} The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.
**
** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.  {A17032} The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.  {H17033} SQLite will
** never do either. {END}
**
** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
** behave as no-ops.
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
sqlite3_mutex *sqlite3_mutex_alloc(int);
void sqlite3_mutex_free(sqlite3_mutex*);
void sqlite3_mutex_enter(sqlite3_mutex*);
int sqlite3_mutex_try(sqlite3_mutex*);
void sqlite3_mutex_leave(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Methods Object {H17120} <S20130>
** EXPERIMENTAL
**
** An instance of this structure defines the low-level routines
** used to allocate and use mutexes.
**
** Usually, the default mutex implementations provided by SQLite are
** sufficient, however the user has the option of substituting a custom
................................................................................
** does not provide a suitable implementation. In this case, the user
** creates and populates an instance of this structure to pass
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
** Additionally, an instance of this structure can be used as an
** output variable when querying the system for the current mutex
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
**
** The xMutexInit method defined by this structure is invoked as
** part of system initialization by the sqlite3_initialize() function.
** {H17001} The xMutexInit routine shall be called by SQLite once for each
** effective call to [sqlite3_initialize()].
**
** The xMutexEnd method defined by this structure is invoked as
** part of system shutdown by the sqlite3_shutdown() function. The
** implementation of this method is expected to release all outstanding
** resources obtained by the mutex methods implementation, especially
** those obtained by the xMutexInit method. {H17003} The xMutexEnd()
** interface shall be invoked once for each call to [sqlite3_shutdown()].
**
** The remaining seven methods defined by this structure (xMutexAlloc,
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
** xMutexNotheld) implement the following interfaces (respectively):
**
** <ul>
**   <li>  [sqlite3_mutex_alloc()] </li>
**   <li>  [sqlite3_mutex_free()] </li>
**   <li>  [sqlite3_mutex_enter()] </li>
**   <li>  [sqlite3_mutex_try()] </li>
**   <li>  [sqlite3_mutex_leave()] </li>
**   <li>  [sqlite3_mutex_held()] </li>
**   <li>  [sqlite3_mutex_notheld()] </li>
** </ul>
**
** The only difference is that the public sqlite3_XXX functions enumerated
** above silently ignore any invocations that pass a NULL pointer instead
** of a valid mutex handle. The implementations of the methods defined
** by this structure are not required to handle this case, the results
** of passing a NULL pointer instead of a valid mutex handle are undefined
** (i.e. it is acceptable to provide an implementation that segfaults if
** it is passed a NULL pointer).
**
** The xMutexInit() method must be threadsafe.  It must be harmless to
** invoke xMutexInit() mutiple times within the same process and without
** intervening calls to xMutexEnd().  Second and subsequent calls to
** xMutexInit() must be no-ops.
**
** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
** and its associates).  Similarly, xMutexAlloc() must not use SQLite memory
** allocation for a static mutex.  However xMutexAlloc() may use SQLite
** memory allocation for a fast or recursive mutex.
**
** SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
** If xMutexInit fails in any way, it is expected to clean up after itself
** prior to returning.
*/
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
struct sqlite3_mutex_methods {
  int (*xMutexInit)(void);
................................................................................
  int (*xMutexTry)(sqlite3_mutex *);
  void (*xMutexLeave)(sqlite3_mutex *);
  int (*xMutexHeld)(sqlite3_mutex *);
  int (*xMutexNotheld)(sqlite3_mutex *);
};

/*
** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800>
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements. {H17081} The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  {H17082} The core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  {A17087} External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** {H17083} These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread.
**
** {X17084} The implementation is not required to provided versions of these
** routines that actually work. If the implementation does not provide working
** versions of these routines, it should at least provide stubs that always
** return true so that one does not get spurious assertion failures.
**
** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1.  {END} This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist.  But the
** the reason the mutex does not exist is because the build is not
** using mutexes.  And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do.  {H17086} The sqlite3_mutex_notheld()
** interface should also return 1 when given a NULL pointer.
*/

int sqlite3_mutex_held(sqlite3_mutex*);
int sqlite3_mutex_notheld(sqlite3_mutex*);


/*
** CAPI3REF: Mutex Types {H17001} <H17000>
**
** The [sqlite3_mutex_alloc()] interface takes a single argument
** which is one of these integer constants.
**
** The set of static mutexes may change from one SQLite release to the
** next.  Applications that override the built-in mutex logic must be
** prepared to accommodate additional static mutexes.
................................................................................
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

/*
** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000>
**
** This interface returns a pointer the [sqlite3_mutex] object that 
** serializes access to the [database connection] given in the argument
** when the [threading mode] is Serialized.
** If the [threading mode] is Single-thread or Multi-thread then this
** routine returns a NULL pointer.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3*);

/*
** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800>
**
** {H11301} The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. {H11302} The
** name of the database is the name assigned to the database by the
** <a href="lang_attach.html">ATTACH</a> SQL command that opened the


** database. {H11303} To control the main database file, use the name "main"
** or a NULL pointer. {H11304} The third and fourth parameters to this routine
** are passed directly through to the second and third parameters of
** the xFileControl method.  {H11305} The return value of the xFileControl
** method becomes the return value of this routine.
**
** {H11306} If the second parameter (zDbName) does not match the name of any
** open database file, then SQLITE_ERROR is returned. {H11307} This error
** code is not remembered and will not be recalled by [sqlite3_errcode()]
** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might
** also return SQLITE_ERROR.  {A11309} There is no way to distinguish between
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
** xFileControl method. {END}
**
** See also: [SQLITE_FCNTL_LOCKSTATE]
*/
int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);

/*
** CAPI3REF: Testing Interface {H11400} <S30800>
**
** The sqlite3_test_control() interface is used to read out internal
** state of SQLite and to inject faults into SQLite for testing
** purposes.  The first parameter is an operation code that determines
** the number, meaning, and operation of all subsequent parameters.
**
** This interface is not for use by applications.  It exists solely
** for verifying the correct operation of the SQLite library.  Depending
** on how the SQLite library is compiled, this interface might not exist.
**
** The details of the operation codes, their meanings, the parameters
................................................................................
** they take, and what they do are all subject to change without notice.
** Unlike most of the SQLite API, this function is not guaranteed to
** operate consistently from one release to the next.
*/
int sqlite3_test_control(int op, ...);

/*
** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400>
**
** These constants are the valid operation code parameters used
** as the first argument to [sqlite3_test_control()].
**
** These parameters and their meanings are subject to change
** without notice.  These values are for testing purposes only.
** Applications should not use any of these parameters or the
................................................................................
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
#define SQLITE_TESTCTRL_PENDING_BYTE            11
#define SQLITE_TESTCTRL_ASSERT                  12
#define SQLITE_TESTCTRL_ALWAYS                  13
#define SQLITE_TESTCTRL_RESERVE                 14

/*
** CAPI3REF: SQLite Runtime Status {H17200} <S60200>
** EXPERIMENTAL
**
** This interface is used to retrieve runtime status information
** about the preformance of SQLite, and optionally to reset various
** highwater marks.  The first argument is an integer code for
** the specific parameter to measure.  Recognized integer codes
** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].
** The current value of the parameter is returned into *pCurrent.
** The highest recorded value is returned in *pHighwater.  If the
** resetFlag is true, then the highest record value is reset after
** *pHighwater is written. Some parameters do not record the highest
** value.  For those parameters
** nothing is written into *pHighwater and the resetFlag is ignored.
** Other parameters record only the highwater mark and not the current
** value.  For these latter parameters nothing is written into *pCurrent.
**
** This routine returns SQLITE_OK on success and a non-zero
** [error code] on failure.
**
** This routine is threadsafe but is not atomic.  This routine can be
** called while other threads are running the same or different SQLite
** interfaces.  However the values returned in *pCurrent and
** *pHighwater reflect the status of SQLite at different points in time
** and it is possible that another thread might change the parameter
** in between the times when *pCurrent and *pHighwater are written.
................................................................................
**
** See also: [sqlite3_db_status()]
*/
SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);


/*
** CAPI3REF: Status Parameters {H17250} <H17200>
** EXPERIMENTAL
**
** These integer constants designate various run-time status parameters
** that can be returned by [sqlite3_status()].
**
** <dl>
** <dt>SQLITE_STATUS_MEMORY_USED</dt>
** <dd>This parameter is the current amount of memory checked out
** using [sqlite3_malloc()], either directly or indirectly.  The
** figure includes calls made to [sqlite3_malloc()] by the application
** and internal memory usage by the SQLite library.  Scratch memory
** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
** this parameter.  The amount returned is the sum of the allocation
** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>
**
** <dt>SQLITE_STATUS_MALLOC_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
** internal equivalents).  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>
**
** <dt>SQLITE_STATUS_PAGECACHE_USED</dt>
** <dd>This parameter returns the number of pages used out of the
** [pagecache memory allocator] that was configured using 
** [SQLITE_CONFIG_PAGECACHE].  The
** value returned is in pages, not in bytes.</dd>
**
** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
** <dd>This parameter returns the number of bytes of page cache
** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE]
** buffer and where forced to overflow to [sqlite3_malloc()].  The
** returned value includes allocations that overflowed because they
** where too large (they were larger than the "sz" parameter to
** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
** no space was left in the page cache.</dd>
**
** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [pagecache memory allocator].  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>
**
** <dt>SQLITE_STATUS_SCRATCH_USED</dt>
** <dd>This parameter returns the number of allocations used out of the
** [scratch memory allocator] configured using
** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
** in bytes.  Since a single thread may only have one scratch allocation
** outstanding at time, this parameter also reports the number of threads
** using scratch memory at the same time.</dd>
**
** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
** <dd>This parameter returns the number of bytes of scratch memory
** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH]
** buffer and where forced to overflow to [sqlite3_malloc()].  The values
** returned include overflows because the requested allocation was too
** larger (that is, because the requested allocation was larger than the
** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
** slots were available.
** </dd>
**
** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [scratch memory allocator].  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>
**
** <dt>SQLITE_STATUS_PARSER_STACK</dt>
** <dd>This parameter records the deepest parser stack.  It is only
** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>
** </dl>
**
** New status parameters may be added from time to time.
*/
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
................................................................................
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_PARSER_STACK         6
#define SQLITE_STATUS_PAGECACHE_SIZE       7
#define SQLITE_STATUS_SCRATCH_SIZE         8

/*
** CAPI3REF: Database Connection Status {H17500} <S60200>
** EXPERIMENTAL
**
** This interface is used to retrieve runtime status information 
** about a single [database connection].  The first argument is the
** database connection object to be interrogated.  The second argument
** is the parameter to interrogate.  Currently, the only allowed value
** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
** Additional options will likely appear in future releases of SQLite.
**
** The current value of the requested parameter is written into *pCur
** and the highest instantaneous value is written into *pHiwtr.  If
** the resetFlg is true, then the highest instantaneous value is
** reset back down to the current value.
**
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
*/
SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);

/*
** CAPI3REF: Status Parameters for database connections {H17520} <H17500>
** EXPERIMENTAL
**
** These constants are the available integer "verbs" that can be passed as
** the second argument to the [sqlite3_db_status()] interface.
**
** New verbs may be added in future releases of SQLite. Existing verbs
** might be discontinued. Applications should check the return code from
** [sqlite3_db_status()] to make sure that the call worked.
** The [sqlite3_db_status()] interface will return a non-zero error code
** if a discontinued or unsupported verb is invoked.
**
** <dl>
** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
** <dd>This parameter returns the number of lookaside memory slots currently
** checked out.</dd>
** </dl>
*/
#define SQLITE_DBSTATUS_LOOKASIDE_USED     0


/*
** CAPI3REF: Prepared Statement Status {H17550} <S60200>
** EXPERIMENTAL
**
** Each prepared statement maintains various
** [SQLITE_STMTSTATUS_SORT | counters] that measure the number
** of times it has performed specific operations.  These counters can
** be used to monitor the performance characteristics of the prepared
** statements.  For example, if the number of table steps greatly exceeds
** the number of table searches or result rows, that would tend to indicate
** that the prepared statement is using a full table scan rather than
** an index.  
**
** This interface is used to retrieve and reset counter values from
** a [prepared statement].  The first argument is the prepared statement
** object to be interrogated.  The second argument
** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter]
** to be interrogated. 
** The current value of the requested counter is returned.
** If the resetFlg is true, then the counter is reset to zero after this
** interface call returns.
**
** See also: [sqlite3_status()] and [sqlite3_db_status()].
*/
SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);

/*
** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550>
** EXPERIMENTAL
**
** These preprocessor macros define integer codes that name counter
** values associated with the [sqlite3_stmt_status()] interface.
** The meanings of the various counters are as follows:
**
** <dl>
** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
** <dd>This is the number of times that SQLite has stepped forward in
** a table as part of a full table scan.  Large numbers for this counter
** may indicate opportunities for performance improvement through 
** careful use of indices.</dd>
**
** <dt>SQLITE_STMTSTATUS_SORT</dt>
** <dd>This is the number of sort operations that have occurred.
** A non-zero value in this counter may indicate an opportunity to
** improvement performance through careful use of indices.</dd>
**
** </dl>
*/
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
#define SQLITE_STMTSTATUS_SORT              2
................................................................................
typedef struct sqlite3_pcache sqlite3_pcache;

/*
** CAPI3REF: Application Defined Page Cache.
** KEYWORDS: {page cache}
** EXPERIMENTAL
**
** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
** register an alternative page cache implementation by passing in an 
** instance of the sqlite3_pcache_methods structure. The majority of the 
** heap memory used by SQLite is used by the page cache to cache data read 
** from, or ready to be written to, the database file. By implementing a 
** custom page cache using this API, an application can control more 
** precisely the amount of memory consumed by SQLite, the way in which 
** that memory is allocated and released, and the policies used to 
** determine exactly which parts of a database file are cached and for 
** how long.
**
** The contents of the sqlite3_pcache_methods structure are copied to an
** internal buffer by SQLite within the call to [sqlite3_config].  Hence
** the application may discard the parameter after the call to
** [sqlite3_config()] returns.
**
** The xInit() method is called once for each call to [sqlite3_initialize()]
** (usually only once during the lifetime of the process). It is passed
** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set
** up global structures and mutexes required by the custom page cache 
** implementation. 
**
** The xShutdown() method is called from within [sqlite3_shutdown()], 
** if the application invokes this API. It can be used to clean up 
** any outstanding resources before process shutdown, if required.
**
** SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes
** the xInit method, so the xInit method need not be threadsafe.  The
** xShutdown method is only called from [sqlite3_shutdown()] so it does
** not need to be threadsafe either.  All other methods must be threadsafe
** in multithreaded applications.
**
** SQLite will never invoke xInit() more than once without an intervening
** call to xShutdown().
**
** The xCreate() method is used to construct a new cache instance.  SQLite
** will typically create one cache instance for each open database file,
** though this is not guaranteed. The
** first parameter, szPage, is the size in bytes of the pages that must
** be allocated by the cache.  szPage will not be a power of two.  szPage
** will the page size of the database file that is to be cached plus an
** increment (here called "R") of about 100 or 200.  SQLite will use the
** extra R bytes on each page to store metadata about the underlying
** database page on disk.  The value of R depends
** on the SQLite version, the target platform, and how SQLite was compiled.
** R is constant for a particular build of SQLite.  The second argument to
** xCreate(), bPurgeable, is true if the cache being created will
** be used to cache database pages of a file stored on disk, or
** false if it is used for an in-memory database. The cache implementation
** does not have to do anything special based with the value of bPurgeable;
** it is purely advisory.  On a cache where bPurgeable is false, SQLite will
** never invoke xUnpin() except to deliberately delete a page.
** In other words, a cache created with bPurgeable set to false will
** never contain any unpinned pages.
**
** The xCachesize() method may be called at any time by SQLite to set the
** suggested maximum cache-size (number of pages stored by) the cache
** instance passed as the first argument. This is the value configured using
** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter,
** the implementation is not required to do anything with this
** value; it is advisory only.
**
** The xPagecount() method should return the number of pages currently
** stored in the cache.
** 
** The xFetch() method is used to fetch a page and return a pointer to it. 
** A 'page', in this context, is a buffer of szPage bytes aligned at an
** 8-byte boundary. The page to be fetched is determined by the key. The
** mimimum key value is 1. After it has been retrieved using xFetch, the page 
** is considered to be "pinned".
**
** If the requested page is already in the page cache, then the page cache
** implementation must return a pointer to the page buffer with its content
** intact.  If the requested page is not already in the cache, then the
** behavior of the cache implementation is determined by the value of the
** createFlag parameter passed to xFetch, according to the following table:
**
** <table border=1 width=85% align=center>
** <tr><th> createFlag <th> Behaviour when page is not already in cache
** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
**                 Otherwise return NULL.
** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
**                 NULL if allocating a new page is effectively impossible.
** </table>
**
** SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  If
** a call to xFetch() with createFlag==1 returns NULL, then SQLite will
** attempt to unpin one or more cache pages by spilling the content of
** pinned pages to disk and synching the operating system disk cache. After
** attempting to unpin pages, the xFetch() method will be invoked again with
** a createFlag of 2.
**
** xUnpin() is called by SQLite with a pointer to a currently pinned page
** as its second argument. If the third parameter, discard, is non-zero,
** then the page should be evicted from the cache. In this case SQLite 
** assumes that the next time the page is retrieved from the cache using
** the xFetch() method, it will be zeroed. If the discard parameter is
** zero, then the page is considered to be unpinned. The cache implementation
** may choose to evict unpinned pages at any time.
**
** The cache is not required to perform any reference counting. A single 
** call to xUnpin() unpins the page regardless of the number of prior calls 
** to xFetch().
**
** The xRekey() method is used to change the key value associated with the
** page passed as the second argument from oldKey to newKey. If the cache
** previously contains an entry associated with newKey, it should be
** discarded. Any prior cache entry associated with newKey is guaranteed not
** to be pinned.
**
** When SQLite calls the xTruncate() method, the cache must discard all
** existing cache entries with page numbers (keys) greater than or equal
** to the value of the iLimit parameter passed to xTruncate(). If any
** of these pages are pinned, they are implicitly unpinned, meaning that
** they can be safely discarded.
**
** The xDestroy() method is used to delete a cache allocated by xCreate().
** All resources associated with the specified cache should be freed. After
** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
** handle invalid, and will not use it with any other sqlite3_pcache_methods
** functions.
*/
typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
struct sqlite3_pcache_methods {
  void *pArg;
................................................................................
};

/*
** CAPI3REF: Online Backup Object
** EXPERIMENTAL
**
** The sqlite3_backup object records state information about an ongoing
** online backup operation.  The sqlite3_backup object is created by
** a call to [sqlite3_backup_init()] and is destroyed by a call to
** [sqlite3_backup_finish()].
**
** See Also: [Using the SQLite Online Backup API]
*/
typedef struct sqlite3_backup sqlite3_backup;

/*
** CAPI3REF: Online Backup API.
** EXPERIMENTAL
**
** This API is used to overwrite the contents of one database with that
** of another. It is useful either for creating backups of databases or
** for copying in-memory databases to or from persistent files. 
**
** See Also: [Using the SQLite Online Backup API]
**
** Exclusive access is required to the destination database for the 
** duration of the operation. However the source database is only
** read-locked while it is actually being read, it is not locked
** continuously for the entire operation. Thus, the backup may be
** performed on a live database without preventing other users from
** writing to the database for an extended period of time.
** 
** To perform a backup operation: 
**   <ol>
**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
**         backup, 
**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 
**         the data between the two databases, and finally
**     <li><b>sqlite3_backup_finish()</b> is called to release all resources 
**         associated with the backup operation. 
**   </ol>
** There should be exactly one call to sqlite3_backup_finish() for each
** successful call to sqlite3_backup_init().
**
** <b>sqlite3_backup_init()</b>
**
** The first two arguments passed to [sqlite3_backup_init()] are the database
** handle associated with the destination database and the database name 
** used to attach the destination database to the handle. The database name
** is "main" for the main database, "temp" for the temporary database, or
** the name specified as part of the [ATTACH] statement if the destination is
** an attached database. The third and fourth arguments passed to 

** sqlite3_backup_init() identify the [database connection]
** and database name used
** to access the source database. The values passed for the source and 
** destination [database connection] parameters must not be the same.


**
** If an error occurs within sqlite3_backup_init(), then NULL is returned
** and an error code and error message written into the [database connection] 
** passed as the first argument. They may be retrieved using the



** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions.

** Otherwise, if successful, a pointer to an [sqlite3_backup] object is
** returned. This pointer may be used with the sqlite3_backup_step() and
** sqlite3_backup_finish() functions to perform the specified backup 
** operation.
**
** <b>sqlite3_backup_step()</b>
**
** Function [sqlite3_backup_step()] is used to copy up to nPage pages between 
** the source and destination databases, where nPage is the value of the 
** second parameter passed to sqlite3_backup_step(). If nPage is a negative
** value, all remaining source pages are copied. If the required pages are 

** succesfully copied, but there are still more pages to copy before the 
** backup is complete, it returns [SQLITE_OK]. If no error occured and there 
** are no more pages to copy, then [SQLITE_DONE] is returned. If an error 

** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
**
** As well as the case where the destination database file was opened for
** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if
** the destination is an in-memory database with a different page size
** from the source database.
**
** If sqlite3_backup_step() cannot obtain a required file-system lock, then
** the [sqlite3_busy_handler | busy-handler function]
** is invoked (if one is specified). If the 
** busy-handler returns non-zero before the lock is available, then 
** [SQLITE_BUSY] is returned to the caller. In this case the call to
** sqlite3_backup_step() can be retried later. If the source
** [database connection]
** is being used to write to the source database when sqlite3_backup_step()
** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this
** case the call to sqlite3_backup_step() can be retried later on. If
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
** [SQLITE_READONLY] is returned, then 
** there is no point in retrying the call to sqlite3_backup_step(). These 
** errors are considered fatal. At this point the application must accept 
** that the backup operation has failed and pass the backup operation handle 
** to the sqlite3_backup_finish() to release associated resources.
**
** Following the first call to sqlite3_backup_step(), an exclusive lock is
** obtained on the destination file. It is not released until either 
** sqlite3_backup_finish() is called or the backup operation is complete 
** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time 
** a call to sqlite3_backup_step() is made a [shared lock] is obtained on
** the source database file. This lock is released before the
** sqlite3_backup_step() call returns. Because the source database is not
** locked between calls to sqlite3_backup_step(), it may be modified mid-way
** through the backup procedure. If the source database is modified by an
** external process or via a database connection other than the one being
** used by the backup operation, then the backup will be transparently
** restarted by the next call to sqlite3_backup_step(). If the source 
** database is modified by the using the same database connection as is used
** by the backup operation, then the backup database is transparently 
** updated at the same time.
**
** <b>sqlite3_backup_finish()</b>
**
** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the 
** application wishes to abandon the backup operation, the [sqlite3_backup]

** object should be passed to sqlite3_backup_finish(). This releases all
** resources associated with the backup operation. If sqlite3_backup_step()
** has not yet returned [SQLITE_DONE], then any active write-transaction on the

** destination database is rolled back. The [sqlite3_backup] object is invalid
** and may not be used following a call to sqlite3_backup_finish().
**
** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error
** occurred, regardless or whether or not sqlite3_backup_step() was called
** a sufficient number of times to complete the backup operation. Or, if

** an out-of-memory condition or IO error occured during a call to
** sqlite3_backup_step() then [SQLITE_NOMEM] or an
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code
** is returned. In this case the error code and an error message are
** written to the destination [database connection].
**
** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is
** not a permanent error and does not affect the return value of
** sqlite3_backup_finish().
**
** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b>
**
** Each call to sqlite3_backup_step() sets two values stored internally
** by an [sqlite3_backup] object. The number of pages still to be backed
** up, which may be queried by sqlite3_backup_remaining(), and the total
** number of pages in the source database file, which may be queried by
** sqlite3_backup_pagecount().

**
** The values returned by these functions are only updated by
** sqlite3_backup_step(). If the source database is modified during a backup
** operation, then the values are not updated to account for any extra
** pages that need to be updated or the size of the source database file
** changing.
**
** <b>Concurrent Usage of Database Handles</b>
**
** The source [database connection] may be used by the application for other
** purposes while a backup operation is underway or being initialized.
** If SQLite is compiled and configured to support threadsafe database
** connections, then the source database connection may be used concurrently
** from within other threads.
**
** However, the application must guarantee that the destination database
** connection handle is not passed to any other API (by any thread) after 
** sqlite3_backup_init() is called and before the corresponding call to
** sqlite3_backup_finish(). Unfortunately SQLite does not currently check
** for this, if the application does use the destination [database connection]
** for some other purpose during a backup operation, things may appear to
** work correctly but in fact be subtly malfunctioning.  Use of the
** destination database connection while a backup is in progress might
** also cause a mutex deadlock.
**
** Furthermore, if running in [shared cache mode], the application must
** guarantee that the shared cache used by the destination database
** is not accessed while the backup is running. In practice this means
** that the application must guarantee that the file-system file being 
** backed up to is not accessed by any connection within the process,
** not just the specific connection that was passed to sqlite3_backup_init().
**
** The [sqlite3_backup] object itself is partially threadsafe. Multiple 
** threads may safely make multiple concurrent calls to sqlite3_backup_step().
** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
** APIs are not strictly speaking threadsafe. If they are invoked at the
................................................................................
int sqlite3_backup_remaining(sqlite3_backup *p);
int sqlite3_backup_pagecount(sqlite3_backup *p);

/*
** CAPI3REF: Unlock Notification
** EXPERIMENTAL
**
** When running in shared-cache mode, a database operation may fail with
** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
** individual tables within the shared-cache cannot be obtained. See
** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 
** This API may be used to register a callback that SQLite will invoke 
** when the connection currently holding the required lock relinquishes it.
** This API is only available if the library was compiled with the
** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
**
** See Also: [Using the SQLite Unlock Notification Feature].
**
** Shared-cache locks are released when a database connection concludes
** its current transaction, either by committing it or rolling it back. 
**
** When a connection (known as the blocked connection) fails to obtain a
** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
** identity of the database connection (the blocking connection) that
** has locked the required resource is stored internally. After an 
** application receives an SQLITE_LOCKED error, it may call the
** sqlite3_unlock_notify() method with the blocked connection handle as 
** the first argument to register for a callback that will be invoked
** when the blocking connections current transaction is concluded. The
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
** call that concludes the blocking connections transaction.
**
** If sqlite3_unlock_notify() is called in a multi-threaded application,
** there is a chance that the blocking connection will have already
** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
** If this happens, then the specified callback is invoked immediately,
** from within the call to sqlite3_unlock_notify().
**
** If the blocked connection is attempting to obtain a write-lock on a
** shared-cache table, and more than one other connection currently holds
** a read-lock on the same table, then SQLite arbitrarily selects one of 
** the other connections to use as the blocking connection.
**
** There may be at most one unlock-notify callback registered by a 
** blocked connection. If sqlite3_unlock_notify() is called when the
** blocked connection already has a registered unlock-notify callback,
** then the new callback replaces the old. If sqlite3_unlock_notify() is
** called with a NULL pointer as its second argument, then any existing
** unlock-notify callback is cancelled. The blocked connections 
** unlock-notify callback may also be canceled by closing the blocked
** connection using [sqlite3_close()].
**
** The unlock-notify callback is not reentrant. If an application invokes
** any sqlite3_xxx API functions from within an unlock-notify callback, a
** crash or deadlock may be the result.
**
** Unless deadlock is detected (see below), sqlite3_unlock_notify() always
** returns SQLITE_OK.
**
** <b>Callback Invocation Details</b>
**
** When an unlock-notify callback is registered, the application provides a 
** single void* pointer that is passed to the callback when it is invoked.
** However, the signature of the callback function allows SQLite to pass
** it an array of void* context pointers. The first argument passed to
** an unlock-notify callback is a pointer to an array of void* pointers,
** and the second is the number of entries in the array.
**
** When a blocking connections transaction is concluded, there may be
** more than one blocked connection that has registered for an unlock-notify
** callback. If two or more such blocked connections have specified the
** same callback function, then instead of invoking the callback function
** multiple times, it is invoked once with the set of void* context pointers
** specified by the blocked connections bundled together into an array.
** This gives the application an opportunity to prioritize any actions 
** related to the set of unblocked database connections.
**
** <b>Deadlock Detection</b>
................................................................................
** action (a reasonable assumption), then using this API may cause the
** application to deadlock. For example, if connection X is waiting for
** connection Y's transaction to be concluded, and similarly connection
** Y is waiting on connection X's transaction, then neither connection
** will proceed and the system may remain deadlocked indefinitely.
**
** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
** detection. If a given call to sqlite3_unlock_notify() would put the
** system in a deadlocked state, then SQLITE_LOCKED is returned and no
** unlock-notify callback is registered. The system is said to be in
** a deadlocked state if connection A has registered for an unlock-notify
** callback on the conclusion of connection B's transaction, and connection
** B has itself registered for an unlock-notify callback when connection
** A's transaction is concluded. Indirect deadlock is also detected, so
** the system is also considered to be deadlocked if connection B has
** registered for an unlock-notify callback on the conclusion of connection
** C's transaction, where connection C is waiting on connection A. Any
** number of levels of indirection are allowed.
**
** <b>The "DROP TABLE" Exception</b>
**
** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 
** always appropriate to call sqlite3_unlock_notify(). There is however,
** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
................................................................................
** that belong to the same connection. If there are, SQLITE_LOCKED is
** returned. In this case there is no "blocking connection", so invoking
** sqlite3_unlock_notify() results in the unlock-notify callback being
** invoked immediately. If the application then re-attempts the "DROP TABLE"
** or "DROP INDEX" query, an infinite loop might be the result.
**
** One way around this problem is to check the extended error code returned
** by an sqlite3_step() call. If there is a blocking connection, then the
** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
** the special "DROP TABLE/INDEX" case, the extended error code is just 
** SQLITE_LOCKED.
*/
int sqlite3_unlock_notify(
  sqlite3 *pBlocked,                          /* Waiting connection */
  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
  void *pNotifyArg                            /* Argument to pass to xNotify */
);


/*
** CAPI3REF: String Comparison
** EXPERIMENTAL
**
** The [sqlite3_strnicmp()] API allows applications and extensions to
** compare the contents of two buffers containing UTF-8 strings in a
** case-indendent fashion, using the same definition of case independence 
** that SQLite uses internally when comparing identifiers.
*/
int sqlite3_strnicmp(const char *, const char *, int);

/*

# undef SQLITE_VERSION
#endif
#ifdef SQLITE_VERSION_NUMBER
# undef SQLITE_VERSION_NUMBER
#endif

/*
** CAPI3REF: Compile-Time Library Version Numbers
**
** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
** evaluates to a string literal that is the SQLite version in the
** format "X.Y.Z" where X is the major version number (always 3 for





** SQLite3) and Y is the minor version number and Z is the release number.)^






** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
** numbers used in [SQLITE_VERSION].)^
** The SQLITE_VERSION_NUMBER for any given release of SQLite will also

** be larger than the release from which it is derived.  Either Y will
** be held constant and Z will be incremented or else Y will be incremented
** and Z will be reset to zero.
**




** Since version 3.6.18, SQLite source code has been stored in the
** <a href="http://www.fossil-scm.org/">Fossil configuration management
** system</a>.  ^The SQLITE_SOURCE_ID macro evalutes to
** a string which identifies a particular check-in of SQLite
** within its configuration management system.  ^The SQLITE_SOURCE_ID
** string contains the date and time of the check-in (UTC) and an SHA1
** hash of the entire source tree.
**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].


*/
#define SQLITE_VERSION        "--VERS--"
#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
#define SQLITE_SOURCE_ID      "--SOURCE-ID--"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
** but are associated with the library instead of the header file.  ^(Cautious
** programmers might include assert() statements in their application to
** verify that values returned by these interfaces match the macros in
** the header, and thus insure that the application is
** compiled with matching library and header files.
**
** <blockquote><pre>
** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
** </pre></blockquote>)^
**
** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
** macro.  ^The sqlite3_libversion() function returns a pointer to the
** to the sqlite3_version[] string constant.  The sqlite3_libversion()
** function is provided for use in DLLs since DLL users usually do not have
** direct access to string constants within the DLL.  ^The
** sqlite3_libversion_number() function returns an integer equal to
** [SQLITE_VERSION_NUMBER].  ^The sqlite3_sourceid() function a pointer
** to a string constant whose value is the same as the [SQLITE_SOURCE_ID]
** C preprocessor macro.
**
** See also: [sqlite_version()] and [sqlite_source_id()].
*/
SQLITE_EXTERN const char sqlite3_version[];
const char *sqlite3_libversion(void);
const char *sqlite3_sourceid(void);
int sqlite3_libversion_number(void);

/*
** CAPI3REF: Test To See If The Library Is Threadsafe
**
** ^The sqlite3_threadsafe() function returns zero if and only if
** SQLite was compiled mutexing code omitted due to the
** [SQLITE_THREADSAFE] compile-time option being set to 0.
**
** SQLite can be compiled with or without mutexes.  When
** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
** are enabled and SQLite is threadsafe.  When the
** [SQLITE_THREADSAFE] macro is 0, 
** the mutexes are omitted.  Without the mutexes, it is not safe
** to use SQLite concurrently from more than one thread.
**
** Enabling mutexes incurs a measurable performance penalty.
** So if speed is of utmost importance, it makes sense to disable
** the mutexes.  But for maximum safety, mutexes should be enabled.
** ^The default behavior is for mutexes to be enabled.
**
** This interface can be used by an application to make sure that the
** version of SQLite that it is linking against was compiled with
** the desired setting of the [SQLITE_THREADSAFE] macro.
**
** This interface only reports on the compile-time mutex setting
** of the [SQLITE_THREADSAFE] flag.  If SQLite is compiled with
** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
** can be fully or partially disabled using a call to [sqlite3_config()]
** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
** or [SQLITE_CONFIG_MUTEX].  ^(The return value of the
** sqlite3_threadsafe() function shows only the compile-time setting of
** thread safety, not any run-time changes to that setting made by
** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
** is unchanged by calls to sqlite3_config().)^
**
** See the [threading mode] documentation for additional information.
*/
int sqlite3_threadsafe(void);

/*
** CAPI3REF: Database Connection Handle
** KEYWORDS: {database connection} {database connections}
**
** Each open SQLite database is represented by a pointer to an instance of
** the opaque structure named "sqlite3".  It is useful to think of an sqlite3
** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
** is its destructor.  There are many other interfaces (such as
................................................................................
** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
** [sqlite3_busy_timeout()] to name but three) that are methods on an
** sqlite3 object.
*/
typedef struct sqlite3 sqlite3;

/*
** CAPI3REF: 64-Bit Integer Types
** KEYWORDS: sqlite_int64 sqlite_uint64
**
** Because there is no cross-platform way to specify 64-bit integer types
** SQLite includes typedefs for 64-bit signed and unsigned integers.
**
** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
** The sqlite_int64 and sqlite_uint64 types are supported for backwards
** compatibility only.
**
** ^The sqlite3_int64 and sqlite_int64 types can store integer values
** between -9223372036854775808 and +9223372036854775807 inclusive.  ^The
** sqlite3_uint64 and sqlite_uint64 types can store integer values 
** between 0 and +18446744073709551615 inclusive.
*/
#ifdef SQLITE_INT64_TYPE
  typedef SQLITE_INT64_TYPE sqlite_int64;
  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
#elif defined(_MSC_VER) || defined(__BORLANDC__)
  typedef __int64 sqlite_int64;
  typedef unsigned __int64 sqlite_uint64;
................................................................................
** substitute integer for floating-point.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite3_int64
#endif

/*
** CAPI3REF: Closing A Database Connection
**
** ^The sqlite3_close() routine is the destructor for the [sqlite3] object.
** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is
** successfullly destroyed and all associated resources are deallocated.
**
** Applications must [sqlite3_finalize | finalize] all [prepared statements]
** and [sqlite3_blob_close | close] all [BLOB handles] associated with
** the [sqlite3] object prior to attempting to close the object.  ^If
** sqlite3_close() is called on a [database connection] that still has
** outstanding [prepared statements] or [BLOB handles], then it returns
** SQLITE_BUSY.
**
** ^If [sqlite3_close()] is invoked while a transaction is open,
** the transaction is automatically rolled back.
**
** The C parameter to [sqlite3_close(C)] must be either a NULL
** pointer or an [sqlite3] object pointer obtained
** from [sqlite3_open()], [sqlite3_open16()], or
** [sqlite3_open_v2()], and not previously closed.
** ^Calling sqlite3_close() with a NULL pointer argument is a 
** harmless no-op.

*/
int sqlite3_close(sqlite3 *);

/*
** The type for a callback function.
** This is legacy and deprecated.  It is included for historical
** compatibility and is not documented.
*/
typedef int (*sqlite3_callback)(void*,int,char**, char**);

/*
** CAPI3REF: One-Step Query Execution Interface
**
** The sqlite3_exec() interface is a convenience wrapper around
** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
** that allows an application to run multiple statements of SQL
** without having to use a lot of C code. 





**
** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
** semicolon-separate SQL statements passed into its 2nd argument,
** in the context of the [database connection] passed in as its 1st
** argument.  ^If the callback function of the 3rd argument to
** sqlite3_exec() is not NULL, then it is invoked for each result row
** coming out of the evaluated SQL statements.  ^The 4th argument to
** to sqlite3_exec() is relayed through to the 1st argument of each
** callback invocation.  ^If the callback pointer to sqlite3_exec()
** is NULL, then no callback is ever invoked and result rows are
** ignored.
**
** ^If an error occurs while evaluating the SQL statements passed into
** sqlite3_exec(), then execution of the current statement stops and
** subsequent statements are skipped.  ^If the 5th parameter to sqlite3_exec()
** is not NULL then any error message is written into memory obtained
** from [sqlite3_malloc()] and passed back through the 5th parameter.
** To avoid memory leaks, the application should invoke [sqlite3_free()]
** on error message strings returned through the 5th parameter of
** of sqlite3_exec() after the error message string is no longer needed.
** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
** NULL before returning.
**


** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
** routine returns SQLITE_ABORT without invoking the callback again and
** without running any subsequent SQL statements.
**


** ^The 2nd argument to the sqlite3_exec() callback function is the
** number of columns in the result.  ^The 3rd argument to the sqlite3_exec()
** callback is an array of pointers to strings obtained as if from
** [sqlite3_column_text()], one for each column.  ^If an element of a
** result row is NULL then the corresponding string pointer for the
** sqlite3_exec() callback is a NULL pointer.  ^The 4th argument to the
** sqlite3_exec() callback is an array of pointers to strings where each
** entry represents the name of corresponding result column as obtained
** from [sqlite3_column_name()].
**



** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
** to an empty string, or a pointer that contains only whitespace and/or 
** SQL comments, then no SQL statements are evaluated and the database
** is not changed.
**


** Restrictions:
**



** <ul>
** <li> The application must insure that the 1st parameter to sqlite3_exec()
**      is a valid and open [database connection].
** <li> The application must not close [database connection] specified by
**      the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
** <li> The application must not modify the SQL statement text passed into
**      the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
** </ul>
*/
int sqlite3_exec(
  sqlite3*,                                  /* An open database */
  const char *sql,                           /* SQL to be evaluated */
  int (*callback)(void*,int,char**,char**),  /* Callback function */
  void *,                                    /* 1st argument to callback */
  char **errmsg                              /* Error msg written here */
);

/*
** CAPI3REF: Result Codes
** KEYWORDS: SQLITE_OK {error code} {error codes}
** KEYWORDS: {result code} {result codes}
**
** Many SQLite functions return an integer result code from the set shown
** here in order to indicates success or failure.
**
** New error codes may be added in future versions of SQLite.
................................................................................
#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
#define SQLITE_NOTADB      26   /* File opened that is not a database file */
#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
/* end-of-error-codes */

/*
** CAPI3REF: Extended Result Codes
** KEYWORDS: {extended error code} {extended error codes}
** KEYWORDS: {extended result code} {extended result codes}
**
** In its default configuration, SQLite API routines return one of 26 integer
** [SQLITE_OK | result codes].  However, experience has shown that many of
** these result codes are too coarse-grained.  They do not provide as
** much information about problems as programmers might like.  In an effort to
................................................................................
#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
#define SQLITE_IOERR_LOCK              (SQLITE_IOERR | (15<<8))
#define SQLITE_IOERR_CLOSE             (SQLITE_IOERR | (16<<8))
#define SQLITE_IOERR_DIR_CLOSE         (SQLITE_IOERR | (17<<8))
#define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED | (1<<8) )

/*
** CAPI3REF: Flags For File Open Operations
**
** These bit values are intended for use in the
** 3rd parameter to the [sqlite3_open_v2()] interface and
** in the 4th parameter to the xOpen method of the
** [sqlite3_vfs] object.
*/
#define SQLITE_OPEN_READONLY         0x00000001  /* Ok for sqlite3_open_v2() */
................................................................................
#define SQLITE_OPEN_MASTER_JOURNAL   0x00004000  /* VFS only */
#define SQLITE_OPEN_NOMUTEX          0x00008000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_FULLMUTEX        0x00010000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_SHAREDCACHE      0x00020000  /* Ok for sqlite3_open_v2() */
#define SQLITE_OPEN_PRIVATECACHE     0x00040000  /* Ok for sqlite3_open_v2() */

/*
** CAPI3REF: Device Characteristics
**
** The xDeviceCapabilities method of the [sqlite3_io_methods]
** object returns an integer which is a vector of the these
** bit values expressing I/O characteristics of the mass storage
** device that holds the file that the [sqlite3_io_methods]
** refers to.
**
................................................................................
#define SQLITE_IOCAP_ATOMIC16K       0x00000040
#define SQLITE_IOCAP_ATOMIC32K       0x00000080
#define SQLITE_IOCAP_ATOMIC64K       0x00000100
#define SQLITE_IOCAP_SAFE_APPEND     0x00000200
#define SQLITE_IOCAP_SEQUENTIAL      0x00000400

/*
** CAPI3REF: File Locking Levels
**
** SQLite uses one of these integer values as the second
** argument to calls it makes to the xLock() and xUnlock() methods
** of an [sqlite3_io_methods] object.
*/
#define SQLITE_LOCK_NONE          0
#define SQLITE_LOCK_SHARED        1
#define SQLITE_LOCK_RESERVED      2
#define SQLITE_LOCK_PENDING       3
#define SQLITE_LOCK_EXCLUSIVE     4

/*
** CAPI3REF: Synchronization Type Flags
**
** When SQLite invokes the xSync() method of an
** [sqlite3_io_methods] object it uses a combination of
** these integer values as the second argument.
**
** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
** sync operation only needs to flush data to mass storage.  Inode
................................................................................
** to use Mac OS X style fullsync instead of fsync().
*/
#define SQLITE_SYNC_NORMAL        0x00002
#define SQLITE_SYNC_FULL          0x00003
#define SQLITE_SYNC_DATAONLY      0x00010

/*
** CAPI3REF: OS Interface Open File Handle
**
** An [sqlite3_file] object represents an open file in the 
** [sqlite3_vfs | OS interface layer].  Individual OS interface
** implementations will
** want to subclass this object by appending additional fields
** for their own use.  The pMethods entry is a pointer to an
** [sqlite3_io_methods] object that defines methods for performing
................................................................................
*/
typedef struct sqlite3_file sqlite3_file;
struct sqlite3_file {
  const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
};

/*
** CAPI3REF: OS Interface File Virtual Methods Object
**
** Every file opened by the [sqlite3_vfs] xOpen method populates an
** [sqlite3_file] object (or, more commonly, a subclass of the
** [sqlite3_file] object) with a pointer to an instance of this object.
** This object defines the methods used to perform various operations
** against the open file represented by the [sqlite3_file] object.
**
................................................................................
  int (*xFileControl)(sqlite3_file*, int op, void *pArg);
  int (*xSectorSize)(sqlite3_file*);
  int (*xDeviceCharacteristics)(sqlite3_file*);
  /* Additional methods may be added in future releases */
};

/*
** CAPI3REF: Standard File Control Opcodes
**
** These integer constants are opcodes for the xFileControl method
** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
** interface.
**
** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
** opcode causes the xFileControl method to write the current state of
................................................................................
*/
#define SQLITE_FCNTL_LOCKSTATE        1
#define SQLITE_GET_LOCKPROXYFILE      2
#define SQLITE_SET_LOCKPROXYFILE      3
#define SQLITE_LAST_ERRNO             4

/*
** CAPI3REF: Mutex Handle
**
** The mutex module within SQLite defines [sqlite3_mutex] to be an
** abstract type for a mutex object.  The SQLite core never looks
** at the internal representation of an [sqlite3_mutex].  It only
** deals with pointers to the [sqlite3_mutex] object.
**
** Mutexes are created using [sqlite3_mutex_alloc()].
*/
typedef struct sqlite3_mutex sqlite3_mutex;

/*
** CAPI3REF: OS Interface Object
**
** An instance of the sqlite3_vfs object defines the interface between
** the SQLite core and the underlying operating system.  The "vfs"
** in the name of the object stands for "virtual file system".
**
** The value of the iVersion field is initially 1 but may be larger in
** future versions of SQLite.  Additional fields may be appended to this
................................................................................
  int (*xCurrentTime)(sqlite3_vfs*, double*);
  int (*xGetLastError)(sqlite3_vfs*, int, char *);
  /* New fields may be appended in figure versions.  The iVersion
  ** value will increment whenever this happens. */
};

/*
** CAPI3REF: Flags for the xAccess VFS method
**
** These integer constants can be used as the third parameter to
** the xAccess method of an [sqlite3_vfs] object.  They determine
** what kind of permissions the xAccess method is looking for.
** With SQLITE_ACCESS_EXISTS, the xAccess method
** simply checks whether the file exists.
** With SQLITE_ACCESS_READWRITE, the xAccess method
** checks whether the file is both readable and writable.
** With SQLITE_ACCESS_READ, the xAccess method
** checks whether the file is readable.
*/
#define SQLITE_ACCESS_EXISTS    0
#define SQLITE_ACCESS_READWRITE 1
#define SQLITE_ACCESS_READ      2

/*
** CAPI3REF: Initialize The SQLite Library
**
** ^The sqlite3_initialize() routine initializes the
** SQLite library.  ^The sqlite3_shutdown() routine
** deallocates any resources that were allocated by sqlite3_initialize().
** These routines are designed to aid in process initialization and
** shutdown on embedded systems.  Workstation applications using
** SQLite normally do not need to invoke either of these routines.
**
** A call to sqlite3_initialize() is an "effective" call if it is
** the first time sqlite3_initialize() is invoked during the lifetime of
** the process, or if it is the first time sqlite3_initialize() is invoked
** following a call to sqlite3_shutdown().  ^(Only an effective call
** of sqlite3_initialize() does any initialization.  All other calls
** are harmless no-ops.)^
**
** A call to sqlite3_shutdown() is an "effective" call if it is the first
** call to sqlite3_shutdown() since the last sqlite3_initialize().  ^(Only
** an effective call to sqlite3_shutdown() does any deinitialization.
** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
**
** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
** is not.  The sqlite3_shutdown() interface must only be called from a
** single thread.  All open [database connections] must be closed and all
** other SQLite resources must be deallocated prior to invoking
** sqlite3_shutdown().
**
** Among other things, ^sqlite3_initialize() will invoke
** sqlite3_os_init().  Similarly, ^sqlite3_shutdown()
** will invoke sqlite3_os_end().
**
** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
** ^If for some reason, sqlite3_initialize() is unable to initialize
** the library (perhaps it is unable to allocate a needed resource such
** as a mutex) it returns an [error code] other than [SQLITE_OK].
**
** ^The sqlite3_initialize() routine is called internally by many other
** SQLite interfaces so that an application usually does not need to
** invoke sqlite3_initialize() directly.  For example, [sqlite3_open()]
** calls sqlite3_initialize() so the SQLite library will be automatically
** initialized when [sqlite3_open()] is called if it has not be initialized
** already.  ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
** compile-time option, then the automatic calls to sqlite3_initialize()
** are omitted and the application must call sqlite3_initialize() directly
** prior to using any other SQLite interface.  For maximum portability,
** it is recommended that applications always invoke sqlite3_initialize()
** directly prior to using any other SQLite interface.  Future releases
** of SQLite may require this.  In other words, the behavior exhibited
** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
................................................................................
*/
int sqlite3_initialize(void);
int sqlite3_shutdown(void);
int sqlite3_os_init(void);
int sqlite3_os_end(void);

/*
** CAPI3REF: Configuring The SQLite Library
** EXPERIMENTAL
**
** The sqlite3_config() interface is used to make global configuration
** changes to SQLite in order to tune SQLite to the specific needs of
** the application.  The default configuration is recommended for most
** applications and so this routine is usually not necessary.  It is
** provided to support rare applications with unusual needs.
**
** The sqlite3_config() interface is not threadsafe.  The application
** must insure that no other SQLite interfaces are invoked by other
** threads while sqlite3_config() is running.  Furthermore, sqlite3_config()
** may only be invoked prior to library initialization using
** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
** Note, however, that ^sqlite3_config() can be called as part of the
** implementation of an application-defined [sqlite3_os_init()].
**
** The first argument to sqlite3_config() is an integer
** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines
** what property of SQLite is to be configured.  Subsequent arguments
** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option]
** in the first argument.
**
** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
** ^If the option is unknown or SQLite is unable to set the option
** then this routine returns a non-zero [error code].





*/
SQLITE_EXPERIMENTAL int sqlite3_config(int, ...);

/*
** CAPI3REF: Configure database connections
** EXPERIMENTAL
**
** The sqlite3_db_config() interface is used to make configuration
** changes to a [database connection].  The interface is similar to
** [sqlite3_config()] except that the changes apply to a single
** [database connection] (specified in the first argument).  The
** sqlite3_db_config() interface should only be used immediately after
** the database connection is created using [sqlite3_open()],
** [sqlite3_open16()], or [sqlite3_open_v2()].  
**
** The second argument to sqlite3_db_config(D,V,...)  is the
** configuration verb - an integer code that indicates what
** aspect of the [database connection] is being configured.
** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE].
** New verbs are likely to be added in future releases of SQLite.
** Additional arguments depend on the verb.
**
** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
** the call is considered successful.
*/
SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...);

/*
** CAPI3REF: Memory Allocation Routines
** EXPERIMENTAL
**
** An instance of this object defines the interface between SQLite
** and low-level memory allocation routines.
**
** This object is used in only one place in the SQLite interface.
** A pointer to an instance of this object is the argument to
................................................................................
** conditions.
**
** The xMalloc and xFree methods must work like the
** malloc() and free() functions from the standard C library.
** The xRealloc method must work like realloc() from the standard C library
** with the exception that if the second argument to xRealloc is zero,
** xRealloc must be a no-op - it must not perform any allocation or
** deallocation.  ^SQLite guarantees that the second argument to
** xRealloc is always a value returned by a prior call to xRoundup.
** And so in cases where xRoundup always returns a positive number,
** xRealloc can perform exactly as the standard library realloc() and
** still be in compliance with this specification.
**
** xSize should return the allocated size of a memory allocation
** previously obtained from xMalloc or xRealloc.  The allocated size
................................................................................
  int (*xRoundup)(int);          /* Round up request size to allocation size */
  int (*xInit)(void*);           /* Initialize the memory allocator */
  void (*xShutdown)(void*);      /* Deinitialize the memory allocator */
  void *pAppData;                /* Argument to xInit() and xShutdown() */
};

/*
** CAPI3REF: Configuration Options
** EXPERIMENTAL
**
** These constants are the available integer configuration options that
** can be passed as the first argument to the [sqlite3_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
................................................................................
** should check the return code from [sqlite3_config()] to make sure that
** the call worked.  The [sqlite3_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
** <dd>There are no arguments to this option.  ^This option sets the
** [threading mode] to Single-thread.  In other words, it disables
** all mutexing and puts SQLite into a mode where it can only be used
** by a single thread.   ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** it is not possible to change the [threading mode] from its default
** value of Single-thread and so [sqlite3_config()] will return 
** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
** configuration option.</dd>
**
** <dt>SQLITE_CONFIG_MULTITHREAD</dt>
** <dd>There are no arguments to this option.  ^This option sets the
** [threading mode] to Multi-thread.  In other words, it disables
** mutexing on [database connection] and [prepared statement] objects.
** The application is responsible for serializing access to
** [database connections] and [prepared statements].  But other mutexes
** are enabled so that SQLite will be safe to use in a multi-threaded
** environment as long as no two threads attempt to use the same
** [database connection] at the same time.  ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** it is not possible to set the Multi-thread [threading mode] and
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
**
** <dt>SQLITE_CONFIG_SERIALIZED</dt>
** <dd>There are no arguments to this option.  ^This option sets the
** [threading mode] to Serialized. In other words, this option enables
** all mutexes including the recursive
** mutexes on [database connection] and [prepared statement] objects.
** In this mode (which is the default when SQLite is compiled with
** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
** to [database connections] and [prepared statements] so that the
** application is free to use the same [database connection] or the
** same [prepared statement] in different threads at the same time.
** ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** it is not possible to set the Serialized [threading mode] and
** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
**
** <dt>SQLITE_CONFIG_MALLOC</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The argument specifies
** alternative low-level memory allocation routines to be used in place of
** the memory allocation routines built into SQLite.)^ ^SQLite makes
** its own private copy of the content of the [sqlite3_mem_methods] structure
** before the [sqlite3_config()] call returns.</dd>
**
** <dt>SQLITE_CONFIG_GETMALLOC</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mem_methods] structure.  The [sqlite3_mem_methods]
** structure is filled with the currently defined memory allocation routines.)^
** This option can be used to overload the default memory allocation
** routines with a wrapper that simulations memory allocation failure or
** tracks memory usage, for example. </dd>
**
** <dt>SQLITE_CONFIG_MEMSTATUS</dt>
** <dd> ^This option takes single argument of type int, interpreted as a 
** boolean, which enables or disables the collection of memory allocation 
** statistics. ^(When memory allocation statistics are disabled, the 
** following SQLite interfaces become non-operational:

**   <ul>
**   <li> [sqlite3_memory_used()]
**   <li> [sqlite3_memory_highwater()]
**   <li> [sqlite3_soft_heap_limit()]
**   <li> [sqlite3_status()]
**   </ul>)^
** ^Memory allocation statistics are enabled by default unless SQLite is
** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
** allocation statistics are disabled by default.
** </dd>
**
** <dt>SQLITE_CONFIG_SCRATCH</dt>
** <dd> ^This option specifies a static memory buffer that SQLite can use for
** scratch memory.  There are three arguments:  A pointer an 8-byte
** aligned memory buffer from which the scrach allocations will be
** drawn, the size of each scratch allocation (sz),
** and the maximum number of scratch allocations (N).  The sz
** argument must be a multiple of 16. The sz parameter should be a few bytes
** larger than the actual scratch space required due to internal overhead.
** The first argument must be a pointer to an 8-byte aligned buffer
** of at least sz*N bytes of memory.
** ^SQLite will use no more than one scratch buffer per thread.  So
** N should be set to the expected maximum number of threads.  ^SQLite will
** never require a scratch buffer that is more than 6 times the database
** page size. ^If SQLite needs needs additional scratch memory beyond 
** what is provided by this configuration option, then 
** [sqlite3_malloc()] will be used to obtain the memory needed.</dd>

**
** <dt>SQLITE_CONFIG_PAGECACHE</dt>
** <dd> ^This option specifies a static memory buffer that SQLite can use for
** the database page cache with the default page cache implemenation.  
** This configuration should not be used if an application-define page
** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option.
** There are three arguments to this option: A pointer to 8-byte aligned
** memory, the size of each page buffer (sz), and the number of pages (N).
** The sz argument should be the size of the largest database page
** (a power of two between 512 and 32768) plus a little extra for each
** page header.  ^The page header size is 20 to 40 bytes depending on
** the host architecture.  ^It is harmless, apart from the wasted memory,
** to make sz a little too large.  The first
** argument should point to an allocation of at least sz*N bytes of memory.
** ^SQLite will use the memory provided by the first argument to satisfy its
** memory needs for the first N pages that it adds to cache.  ^If additional
** page cache memory is needed beyond what is provided by this option, then
** SQLite goes to [sqlite3_malloc()] for the additional storage space.
** ^The implementation might use one or more of the N buffers to hold 
** memory accounting information. The pointer in the first argument must
** be aligned to an 8-byte boundary or subsequent behavior of SQLite
** will be undefined.</dd>
**
** <dt>SQLITE_CONFIG_HEAP</dt>
** <dd> ^This option specifies a static memory buffer that SQLite will use
** for all of its dynamic memory allocation needs beyond those provided
** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE].
** There are three arguments: An 8-byte aligned pointer to the memory,
** the number of bytes in the memory buffer, and the minimum allocation size.
** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
** to using its default memory allocator (the system malloc() implementation),
** undoing any prior invocation of [SQLITE_CONFIG_MALLOC].  ^If the
** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or
** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory
** allocator is engaged to handle all of SQLites memory allocation needs.
** The first pointer (the memory pointer) must be aligned to an 8-byte
** boundary or subsequent behavior of SQLite will be undefined.</dd>
**
** <dt>SQLITE_CONFIG_MUTEX</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The argument specifies
** alternative low-level mutex routines to be used in place
** the mutex routines built into SQLite.)^  ^SQLite makes a copy of the
** content of the [sqlite3_mutex_methods] structure before the call to
** [sqlite3_config()] returns. ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** <dt>SQLITE_CONFIG_GETMUTEX</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** instance of the [sqlite3_mutex_methods] structure.  The
** [sqlite3_mutex_methods]
** structure is filled with the currently defined mutex routines.)^
** This option can be used to overload the default mutex allocation
** routines with a wrapper used to track mutex usage for performance
** profiling or testing, for example.   ^If SQLite is compiled with
** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
** the entire mutexing subsystem is omitted from the build and hence calls to
** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
** return [SQLITE_ERROR].</dd>
**
** <dt>SQLITE_CONFIG_LOOKASIDE</dt>
** <dd> ^(This option takes two arguments that determine the default
** memory allocation for the lookaside memory allocator on each
** [database connection].  The first argument is the
** size of each lookaside buffer slot and the second is the number of
** slots allocated to each database connection.)^  ^(This option sets the
** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
** verb to [sqlite3_db_config()] can be used to change the lookaside
** configuration on individual connections.)^ </dd>
**
** <dt>SQLITE_CONFIG_PCACHE</dt>
** <dd> ^(This option takes a single argument which is a pointer to
** an [sqlite3_pcache_methods] object.  This object specifies the interface
** to a custom page cache implementation.)^  ^SQLite makes a copy of the
** object and uses it for page cache memory allocations.</dd>
**
** <dt>SQLITE_CONFIG_GETPCACHE</dt>
** <dd> ^(This option takes a single argument which is a pointer to an
** [sqlite3_pcache_methods] object.  SQLite copies of the current
** page cache implementation into that object.)^ </dd>
**
** </dl>
*/
#define SQLITE_CONFIG_SINGLETHREAD  1  /* nil */
#define SQLITE_CONFIG_MULTITHREAD   2  /* nil */
#define SQLITE_CONFIG_SERIALIZED    3  /* nil */
#define SQLITE_CONFIG_MALLOC        4  /* sqlite3_mem_methods* */
................................................................................
#define SQLITE_CONFIG_GETMUTEX     11  /* sqlite3_mutex_methods* */
/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 
#define SQLITE_CONFIG_LOOKASIDE    13  /* int int */
#define SQLITE_CONFIG_PCACHE       14  /* sqlite3_pcache_methods* */
#define SQLITE_CONFIG_GETPCACHE    15  /* sqlite3_pcache_methods* */

/*
** CAPI3REF: Configuration Options
** EXPERIMENTAL
**
** These constants are the available integer configuration options that
** can be passed as the second argument to the [sqlite3_db_config()] interface.
**
** New configuration options may be added in future releases of SQLite.
** Existing configuration options might be discontinued.  Applications
** should check the return code from [sqlite3_db_config()] to make sure that
** the call worked.  ^The [sqlite3_db_config()] interface will return a
** non-zero [error code] if a discontinued or unsupported configuration option
** is invoked.
**
** <dl>
** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
** <dd> ^This option takes three additional arguments that determine the 
** [lookaside memory allocator] configuration for the [database connection].
** ^The first argument (the third parameter to [sqlite3_db_config()] is a
** pointer to an memory buffer to use for lookaside memory.
** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
** may be NULL in which case SQLite will allocate the
** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
** size of each lookaside buffer slot.  ^The third argument is the number of
** slots.  The size of the buffer in the first argument must be greater than
** or equal to the product of the second and third arguments.  The buffer
** must be aligned to an 8-byte boundary.  ^If the second argument to
** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
** rounded down to the next smaller
** multiple of 8.  See also: [SQLITE_CONFIG_LOOKASIDE]</dd>
**
** </dl>
*/
#define SQLITE_DBCONFIG_LOOKASIDE    1001  /* void* int int */


/*
** CAPI3REF: Enable Or Disable Extended Result Codes
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result
** codes are disabled by default for historical compatibility.



*/
int sqlite3_extended_result_codes(sqlite3*, int onoff);

/*
** CAPI3REF: Last Insert Rowid
**
** ^Each entry in an SQLite table has a unique 64-bit signed
** integer key called the [ROWID | "rowid"]. ^The rowid is always available
** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
** names are not also used by explicitly declared columns. ^If
** the table has a column of type [INTEGER PRIMARY KEY] then that column
** is another alias for the rowid.
**
** ^This routine returns the [rowid] of the most recent
** successful [INSERT] into the database from the [database connection]
** in the first argument.  ^If no successful [INSERT]s
** have ever occurred on that database connection, zero is returned.
**
** ^(If an [INSERT] occurs within a trigger, then the [rowid] of the inserted
** row is returned by this routine as long as the trigger is running.
** But once the trigger terminates, the value returned by this routine
** reverts to the last value inserted before the trigger fired.)^
**
** ^An [INSERT] that fails due to a constraint violation is not a
** successful [INSERT] and does not change the value returned by this
** routine.  ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
** and INSERT OR ABORT make no changes to the return value of this
** routine when their insertion fails.  ^(When INSERT OR REPLACE
** encounters a constraint violation, it does not fail.  The
** INSERT continues to completion after deleting rows that caused
** the constraint problem so INSERT OR REPLACE will always change
** the return value of this interface.)^
**
** ^For the purposes of this routine, an [INSERT] is considered to
** be successful even if it is subsequently rolled back.
**
** This function is accessible to SQL statements via the
** [last_insert_rowid() SQL function].
**



** If a separate thread performs a new [INSERT] on the same
** database connection while the [sqlite3_last_insert_rowid()]
** function is running and thus changes the last insert [rowid],
** then the value returned by [sqlite3_last_insert_rowid()] is
** unpredictable and might not equal either the old or the new
** last insert [rowid].
*/
sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);

/*
** CAPI3REF: Count The Number Of Rows Modified
**
** ^This function returns the number of database rows that were changed
** or inserted or deleted by the most recently completed SQL statement
** on the [database connection] specified by the first parameter.
** ^(Only changes that are directly specified by the [INSERT], [UPDATE],
** or [DELETE] statement are counted.  Auxiliary changes caused by
** triggers or [foreign key actions] are not counted.)^ Use the
** [sqlite3_total_changes()] function to find the total number of changes
** including changes caused by triggers and foreign key actions.
**
** ^Changes to a view that are simulated by an [INSTEAD OF trigger]
** are not counted.  Only real table changes are counted.
**
** ^(A "row change" is a change to a single row of a single table
** caused by an INSERT, DELETE, or UPDATE statement.  Rows that
** are changed as side effects of [REPLACE] constraint resolution,
** rollback, ABORT processing, [DROP TABLE], or by any other
** mechanisms do not count as direct row changes.)^
**
** A "trigger context" is a scope of execution that begins and
** ends with the script of a [CREATE TRIGGER | trigger]. 
** Most SQL statements are
** evaluated outside of any trigger.  This is the "top level"
** trigger context.  If a trigger fires from the top level, a
** new trigger context is entered for the duration of that one
** trigger.  Subtriggers create subcontexts for their duration.
**
** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does
** not create a new trigger context.
**
** ^This function returns the number of direct row changes in the
** most recent INSERT, UPDATE, or DELETE statement within the same
** trigger context.
**
** ^Thus, when called from the top level, this function returns the
** number of changes in the most recent INSERT, UPDATE, or DELETE
** that also occurred at the top level.  ^(Within the body of a trigger,
** the sqlite3_changes() interface can be called to find the number of
** changes in the most recently completed INSERT, UPDATE, or DELETE
** statement within the body of the same trigger.
** However, the number returned does not include changes
** caused by subtriggers since those have their own context.)^
**
** See also the [sqlite3_total_changes()] interface, the
** [count_changes pragma], and the [changes() SQL function].
**



** If a separate thread makes changes on the same database connection
** while [sqlite3_changes()] is running then the value returned
** is unpredictable and not meaningful.
*/
int sqlite3_changes(sqlite3*);

/*
** CAPI3REF: Total Number Of Rows Modified
**
** ^This function returns the number of row changes caused by [INSERT],
** [UPDATE] or [DELETE] statements since the [database connection] was opened.
** ^(The count returned by sqlite3_total_changes() includes all changes
** from all [CREATE TRIGGER | trigger] contexts and changes made by
** [foreign key actions]. However,
** the count does not include changes used to implement [REPLACE] constraints,
** do rollbacks or ABORT processing, or [DROP TABLE] processing.  The
** count does not include rows of views that fire an [INSTEAD OF trigger],
** though if the INSTEAD OF trigger makes changes of its own, those changes 
** are counted.)^
** ^The sqlite3_total_changes() function counts the changes as soon as
** the statement that makes them is completed (when the statement handle
** is passed to [sqlite3_reset()] or [sqlite3_finalize()]).
**
** See also the [sqlite3_changes()] interface, the
** [count_changes pragma], and the [total_changes() SQL function].
**



** If a separate thread makes changes on the same database connection
** while [sqlite3_total_changes()] is running then the value
** returned is unpredictable and not meaningful.
*/
int sqlite3_total_changes(sqlite3*);

/*
** CAPI3REF: Interrupt A Long-Running Query
**
** ^This function causes any pending database operation to abort and
** return at its earliest opportunity. This routine is typically
** called in response to a user action such as pressing "Cancel"
** or Ctrl-C where the user wants a long query operation to halt
** immediately.
**
** ^It is safe to call this routine from a thread different from the
** thread that is currently running the database operation.  But it
** is not safe to call this routine with a [database connection] that
** is closed or might close before sqlite3_interrupt() returns.
**
** ^If an SQL operation is very nearly finished at the time when
** sqlite3_interrupt() is called, then it might not have an opportunity
** to be interrupted and might continue to completion.
**
** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
** that is inside an explicit transaction, then the entire transaction
** will be rolled back automatically.
**
** ^The sqlite3_interrupt(D) call is in effect until all currently running
** SQL statements on [database connection] D complete.  ^Any new SQL statements
** that are started after the sqlite3_interrupt() call and before the 
** running statements reaches zero are interrupted as if they had been
** running prior to the sqlite3_interrupt() call.  ^New SQL statements
** that are started after the running statement count reaches zero are
** not effected by the sqlite3_interrupt().
** ^A call to sqlite3_interrupt(D) that occurs when there are no running
** SQL statements is a no-op and has no effect on SQL statements
** that are started after the sqlite3_interrupt() call returns.
**



** If the database connection closes while [sqlite3_interrupt()]
** is running then bad things will likely happen.
*/
void sqlite3_interrupt(sqlite3*);

/*
** CAPI3REF: Determine If An SQL Statement Is Complete
**
** These routines are useful during command-line input to determine if the
** currently entered text seems to form a complete SQL statement or
** if additional input is needed before sending the text into
** SQLite for parsing.  ^These routines return 1 if the input string
** appears to be a complete SQL statement.  ^A statement is judged to be
** complete if it ends with a semicolon token and is not a prefix of a
** well-formed CREATE TRIGGER statement.  ^Semicolons that are embedded within
** string literals or quoted identifier names or comments are not
** independent tokens (they are part of the token in which they are
** embedded) and thus do not count as a statement terminator.  ^Whitespace
** and comments that follow the final semicolon are ignored.
**
** ^These routines return 0 if the statement is incomplete.  ^If a
** memory allocation fails, then SQLITE_NOMEM is returned.
**
** ^These routines do not parse the SQL statements thus
** will not detect syntactically incorrect SQL.
**
** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 
** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
** automatically by sqlite3_complete16().  If that initialization fails,
** then the return value from sqlite3_complete16() will be non-zero
** regardless of whether or not the input SQL is complete.)^


**
** The input to [sqlite3_complete()] must be a zero-terminated
** UTF-8 string.
**
** The input to [sqlite3_complete16()] must be a zero-terminated
** UTF-16 string in native byte order.
*/
int sqlite3_complete(const char *sql);
int sqlite3_complete16(const void *sql);

/*
** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
**
** ^This routine sets a callback function that might be invoked whenever
** an attempt is made to open a database table that another thread
** or process has locked.
**
** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]
** is returned immediately upon encountering the lock.  ^If the busy callback
** is not NULL, then the callback might be invoked with two arguments.
**
** ^The first argument to the busy handler is a copy of the void* pointer which
** is the third argument to sqlite3_busy_handler().  ^The second argument to
** the busy handler callback is the number of times that the busy handler has
** been invoked for this locking event.  ^If the
** busy callback returns 0, then no additional attempts are made to
** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
** ^If the callback returns non-zero, then another attempt
** is made to open the database for reading and the cycle repeats.
**
** The presence of a busy handler does not guarantee that it will be invoked
** when there is lock contention. ^If SQLite determines that invoking the busy
** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler.
** Consider a scenario where one process is holding a read lock that
** it is trying to promote to a reserved lock and
** a second process is holding a reserved lock that it is trying
** to promote to an exclusive lock.  The first process cannot proceed
** because it is blocked by the second and the second process cannot
** proceed because it is blocked by the first.  If both processes
** invoke the busy handlers, neither will make any progress.  Therefore,
** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
** will induce the first process to release its read lock and allow
** the second process to proceed.
**
** ^The default busy callback is NULL.
**
** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED]
** when SQLite is in the middle of a large transaction where all the
** changes will not fit into the in-memory cache.  SQLite will
** already hold a RESERVED lock on the database file, but it needs
** to promote this lock to EXCLUSIVE so that it can spill cache
** pages into the database file without harm to concurrent
** readers.  ^If it is unable to promote the lock, then the in-memory
** cache will be left in an inconsistent state and so the error
** code is promoted from the relatively benign [SQLITE_BUSY] to
** the more severe [SQLITE_IOERR_BLOCKED].  ^This error code promotion
** forces an automatic rollback of the changes.  See the
** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError">
** CorruptionFollowingBusyError</a> wiki page for a discussion of why
** this is important.
**
** ^(There can only be a single busy handler defined for each
** [database connection].  Setting a new busy handler clears any
** previously set handler.)^  ^Note that calling [sqlite3_busy_timeout()]
** will also set or clear the busy handler.
**
** The busy callback should not take any actions which modify the
** database connection that invoked the busy handler.  Any such actions
** result in undefined behavior.



**
** A busy handler must not close the database connection
** or [prepared statement] that invoked the busy handler.
*/
int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);

/*
** CAPI3REF: Set A Busy Timeout
**
** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
** for a specified amount of time when a table is locked.  ^The handler
** will sleep multiple times until at least "ms" milliseconds of sleeping
** have accumulated.  ^After at least "ms" milliseconds of sleeping,
** the handler returns 0 which causes [sqlite3_step()] to return
** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
**
** ^Calling this routine with an argument less than or equal to zero
** turns off all busy handlers.
**
** ^(There can only be a single busy handler for a particular
** [database connection] any any given moment.  If another busy handler
** was defined  (using [sqlite3_busy_handler()]) prior to calling
** this routine, that other busy handler is cleared.)^



*/
int sqlite3_busy_timeout(sqlite3*, int ms);

/*
** CAPI3REF: Convenience Routines For Running Queries
**
** Definition: A <b>result table</b> is memory data structure created by the
** [sqlite3_get_table()] interface.  A result table records the
** complete query results from one or more queries.
**
** The table conceptually has a number of rows and columns.  But
** these numbers are not part of the result table itself.  These
................................................................................
**        azResult&#91;3] = "43";
**        azResult&#91;4] = "Bob";
**        azResult&#91;5] = "28";
**        azResult&#91;6] = "Cindy";
**        azResult&#91;7] = "21";
** </pre></blockquote>
**
** ^The sqlite3_get_table() function evaluates one or more
** semicolon-separated SQL statements in the zero-terminated UTF-8
** string of its 2nd parameter and returns a result table to the
** pointer given in its 3rd parameter.
**
** After the application has finished with the result from sqlite3_get_table(),
** it should pass the result table pointer to sqlite3_free_table() in order to
** release the memory that was malloced.  Because of the way the
** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
** function must not try to call [sqlite3_free()] directly.  Only
** [sqlite3_free_table()] is able to release the memory properly and safely.
**
** ^(The sqlite3_get_table() interface is implemented as a wrapper around
** [sqlite3_exec()].  The sqlite3_get_table() routine does not have access
** to any internal data structures of SQLite.  It uses only the public
** interface defined here.  As a consequence, errors that occur in the
** wrapper layer outside of the internal [sqlite3_exec()] call are not
** reflected in subsequent calls to [sqlite3_errcode()] or
** [sqlite3_errmsg()].)^


*/
int sqlite3_get_table(
  sqlite3 *db,          /* An open database */
  const char *zSql,     /* SQL to be evaluated */
  char ***pazResult,    /* Results of the query */
  int *pnRow,           /* Number of result rows written here */
  int *pnColumn,        /* Number of result columns written here */
  char **pzErrmsg       /* Error msg written here */
);
void sqlite3_free_table(char **result);

/*
** CAPI3REF: Formatted String Printing Functions
**
** These routines are work-alikes of the "printf()" family of functions
** from the standard C library.
**
** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
** results into memory obtained from [sqlite3_malloc()].
** The strings returned by these two routines should be
** released by [sqlite3_free()].  ^Both routines return a
** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
** memory to hold the resulting string.
**
** ^(In sqlite3_snprintf() routine is similar to "snprintf()" from
** the standard C library.  The result is written into the
** buffer supplied as the second parameter whose size is given by
** the first parameter. Note that the order of the
** first two parameters is reversed from snprintf().)^  This is an
** historical accident that cannot be fixed without breaking
** backwards compatibility.  ^(Note also that sqlite3_snprintf()
** returns a pointer to its buffer instead of the number of
** characters actually written into the buffer.)^  We admit that
** the number of characters written would be a more useful return
** value but we cannot change the implementation of sqlite3_snprintf()
** now without breaking compatibility.
**
** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
** guarantees that the buffer is always zero-terminated.  ^The first
** parameter "n" is the total size of the buffer, including space for
** the zero terminator.  So the longest string that can be completely
** written will be n-1 characters.
**
** These routines all implement some additional formatting
** options that are useful for constructing SQL statements.
** All of the usual printf() formatting options apply.  In addition, there
** is are "%q", "%Q", and "%z" options.
**
** ^(The %q option works like %s in that it substitutes a null-terminated
** string from the argument list.  But %q also doubles every '\'' character.
** %q is designed for use inside a string literal.)^  By doubling each '\''
** character it escapes that character and allows it to be inserted into
** the string.
**
** For example, assume the string variable zText contains text as follows:
**
** <blockquote><pre>
**  char *zText = "It's a happy day!";
................................................................................
** <blockquote><pre>
**  INSERT INTO table1 VALUES('It's a happy day!');
** </pre></blockquote>
**
** This second example is an SQL syntax error.  As a general rule you should
** always use %q instead of %s when inserting text into a string literal.
**
** ^(The %Q option works like %q except it also adds single quotes around
** the outside of the total string.  Additionally, if the parameter in the
** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
** single quotes).)^  So, for example, one could say:
**
** <blockquote><pre>
**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
**  sqlite3_exec(db, zSQL, 0, 0, 0);
**  sqlite3_free(zSQL);
** </pre></blockquote>
**
** The code above will render a correct SQL statement in the zSQL
** variable even if the zText variable is a NULL pointer.
**
** ^(The "%z" formatting option works like "%s" but with the
** addition that after the string has been read and copied into
** the result, [sqlite3_free()] is called on the input string.)^



*/
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);
char *sqlite3_snprintf(int,char*,const char*, ...);

/*
** CAPI3REF: Memory Allocation Subsystem
**
** The SQLite core uses these three routines for all of its own
** internal memory allocation needs. "Core" in the previous sentence
** does not include operating-system specific VFS implementation.  The
** Windows VFS uses native malloc() and free() for some operations.
**
** ^The sqlite3_malloc() routine returns a pointer to a block
** of memory at least N bytes in length, where N is the parameter.
** ^If sqlite3_malloc() is unable to obtain sufficient free
** memory, it returns a NULL pointer.  ^If the parameter N to
** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
** a NULL pointer.
**
** ^Calling sqlite3_free() with a pointer previously returned
** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
** that it might be reused.  ^The sqlite3_free() routine is
** a no-op if is called with a NULL pointer.  Passing a NULL pointer
** to sqlite3_free() is harmless.  After being freed, memory
** should neither be read nor written.  Even reading previously freed
** memory might result in a segmentation fault or other severe error.
** Memory corruption, a segmentation fault, or other severe error
** might result if sqlite3_free() is called with a non-NULL pointer that
** was not obtained from sqlite3_malloc() or sqlite3_realloc().
**
** ^(The sqlite3_realloc() interface attempts to resize a
** prior memory allocation to be at least N bytes, where N is the
** second parameter.  The memory allocation to be resized is the first
** parameter.)^ ^ If the first parameter to sqlite3_realloc()
** is a NULL pointer then its behavior is identical to calling
** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc().
** ^If the second parameter to sqlite3_realloc() is zero or
** negative then the behavior is exactly the same as calling
** sqlite3_free(P) where P is the first parameter to sqlite3_realloc().
** ^sqlite3_realloc() returns a pointer to a memory allocation
** of at least N bytes in size or NULL if sufficient memory is unavailable.
** ^If M is the size of the prior allocation, then min(N,M) bytes
** of the prior allocation are copied into the beginning of buffer returned
** by sqlite3_realloc() and the prior allocation is freed.
** ^If sqlite3_realloc() returns NULL, then the prior allocation
** is not freed.
**
** ^The memory returned by sqlite3_malloc() and sqlite3_realloc()
** is always aligned to at least an 8 byte boundary.









**
** In SQLite version 3.5.0 and 3.5.1, it was possible to define
** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
** implementation of these routines to be omitted.  That capability
** is no longer provided.  Only built-in memory allocators can be used.
**
** The Windows OS interface layer calls
................................................................................
** the system malloc() and free() directly when converting
** filenames between the UTF-8 encoding used by SQLite
** and whatever filename encoding is used by the particular Windows
** installation.  Memory allocation errors are detected, but
** they are reported back as [SQLITE_CANTOPEN] or
** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
**




** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
** must be either NULL or else pointers obtained from a prior
** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
** not yet been released.
**
** The application must not read or write any part of
** a block of memory after it has been released using
................................................................................
** [sqlite3_free()] or [sqlite3_realloc()].
*/
void *sqlite3_malloc(int);
void *sqlite3_realloc(void*, int);
void sqlite3_free(void*);

/*
** CAPI3REF: Memory Allocator Statistics
**
** SQLite provides these two interfaces for reporting on the status
** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
** routines, which form the built-in memory allocation subsystem.
**
** ^The [sqlite3_memory_used()] routine returns the number of bytes
** of memory currently outstanding (malloced but not freed).
** ^The [sqlite3_memory_highwater()] routine returns the maximum
** value of [sqlite3_memory_used()] since the high-water mark
** was last reset.  ^The values returned by [sqlite3_memory_used()] and
** [sqlite3_memory_highwater()] include any overhead
** added by SQLite in its implementation of [sqlite3_malloc()],
** but not overhead added by the any underlying system library
** routines that [sqlite3_malloc()] may call.
**
** ^The memory high-water mark is reset to the current value of
** [sqlite3_memory_used()] if and only if the parameter to
** [sqlite3_memory_highwater()] is true.  ^The value returned
** by [sqlite3_memory_highwater(1)] is the high-water mark
** prior to the reset.
*/
sqlite3_int64 sqlite3_memory_used(void);
sqlite3_int64 sqlite3_memory_highwater(int resetFlag);

/*
** CAPI3REF: Pseudo-Random Number Generator
**
** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
** select random [ROWID | ROWIDs] when inserting new records into a table that
** already uses the largest possible [ROWID].  The PRNG is also used for
** the build-in random() and randomblob() SQL functions.  This interface allows
** applications to access the same PRNG for other purposes.
**
** ^A call to this routine stores N bytes of randomness into buffer P.
**
** ^The first time this routine is invoked (either internally or by
** the application) the PRNG is seeded using randomness obtained
** from the xRandomness method of the default [sqlite3_vfs] object.
** ^On all subsequent invocations, the pseudo-randomness is generated
** internally and without recourse to the [sqlite3_vfs] xRandomness
** method.



*/
void sqlite3_randomness(int N, void *P);

/*
** CAPI3REF: Compile-Time Authorization Callbacks
**
** ^This routine registers a authorizer callback with a particular
** [database connection], supplied in the first argument.
** ^The authorizer callback is invoked as SQL statements are being compiled
** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  ^At various
** points during the compilation process, as logic is being created
** to perform various actions, the authorizer callback is invoked to
** see if those actions are allowed.  ^The authorizer callback should
** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
** specific action but allow the SQL statement to continue to be
** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
** rejected with an error.  ^If the authorizer callback returns
** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
** then the [sqlite3_prepare_v2()] or equivalent call that triggered
** the authorizer will fail with an error message.
**
** When the callback returns [SQLITE_OK], that means the operation
** requested is ok.  ^When the callback returns [SQLITE_DENY], the
** [sqlite3_prepare_v2()] or equivalent call that triggered the
** authorizer will fail with an error message explaining that
** access is denied. 
**
** ^The first parameter to the authorizer callback is a copy of the third
** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
** to the callback is an integer [SQLITE_COPY | action code] that specifies
** the particular action to be authorized. ^The third through sixth parameters
** to the callback are zero-terminated strings that contain additional
** details about the action to be authorized.
**
** ^If the action code is [SQLITE_READ]
** and the callback returns [SQLITE_IGNORE] then the
** [prepared statement] statement is constructed to substitute
** a NULL value in place of the table column that would have
** been read if [SQLITE_OK] had been returned.  The [SQLITE_IGNORE]
** return can be used to deny an untrusted user access to individual
** columns of a table.
** ^If the action code is [SQLITE_DELETE] and the callback returns
** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
** [truncate optimization] is disabled and all rows are deleted individually.
**
** An authorizer is used when [sqlite3_prepare | preparing]
** SQL statements from an untrusted source, to ensure that the SQL statements
** do not try to access data they are not allowed to see, or that they do not
** try to execute malicious statements that damage the database.  For
................................................................................
** disallows everything except [SELECT] statements.
**
** Applications that need to process SQL from untrusted sources
** might also consider lowering resource limits using [sqlite3_limit()]
** and limiting database size using the [max_page_count] [PRAGMA]
** in addition to using an authorizer.
**
** ^(Only a single authorizer can be in place on a database connection
** at a time.  Each call to sqlite3_set_authorizer overrides the
** previous call.)^  ^Disable the authorizer by installing a NULL callback.
** The authorizer is disabled by default.
**
** The authorizer callback must not do anything that will modify
** the database connection that invoked the authorizer callback.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
** statement might be re-prepared during [sqlite3_step()] due to a 
** schema change.  Hence, the application should ensure that the
** correct authorizer callback remains in place during the [sqlite3_step()].
**
** ^Note that the authorizer callback is invoked only during
** [sqlite3_prepare()] or its variants.  Authorization is not
** performed during statement evaluation in [sqlite3_step()], unless
** as stated in the previous paragraph, sqlite3_step() invokes
** sqlite3_prepare_v2() to reprepare a statement after a schema change.




*/
int sqlite3_set_authorizer(
  sqlite3*,
  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
  void *pUserData
);

/*
** CAPI3REF: Authorizer Return Codes
**
** The [sqlite3_set_authorizer | authorizer callback function] must
** return either [SQLITE_OK] or one of these two constants in order
** to signal SQLite whether or not the action is permitted.  See the
** [sqlite3_set_authorizer | authorizer documentation] for additional
** information.
*/
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

/*
** CAPI3REF: Authorizer Action Codes
**
** The [sqlite3_set_authorizer()] interface registers a callback function
** that is invoked to authorize certain SQL statement actions.  The
** second parameter to the callback is an integer code that specifies
** what action is being authorized.  These are the integer action codes that
** the authorizer callback may be passed.
**
** These action code values signify what kind of operation is to be
** authorized.  The 3rd and 4th parameters to the authorization
** callback function will be parameters or NULL depending on which of these
** codes is used as the second parameter.  ^(The 5th parameter to the
** authorizer callback is the name of the database ("main", "temp",
** etc.) if applicable.)^  ^The 6th parameter to the authorizer callback
** is the name of the inner-most trigger or view that is responsible for
** the access attempt or NULL if this access attempt is directly from
** top-level SQL code.



*/
/******************************************* 3rd ************ 4th ***********/
#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
................................................................................
#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
#define SQLITE_FUNCTION             31   /* NULL            Function Name   */
#define SQLITE_SAVEPOINT            32   /* Operation       Savepoint Name  */
#define SQLITE_COPY                  0   /* No longer used */

/*
** CAPI3REF: Tracing And Profiling Functions
** EXPERIMENTAL
**
** These routines register callback functions that can be used for
** tracing and profiling the execution of SQL statements.
**
** ^The callback function registered by sqlite3_trace() is invoked at
** various times when an SQL statement is being run by [sqlite3_step()].
** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
** SQL statement text as the statement first begins executing.
** ^(Additional sqlite3_trace() callbacks might occur
** as each triggered subprogram is entered.  The callbacks for triggers
** contain a UTF-8 SQL comment that identifies the trigger.)^
**
** ^The callback function registered by sqlite3_profile() is invoked
** as each SQL statement finishes.  ^The profile callback contains
** the original statement text and an estimate of wall-clock time
** of how long that statement took to run.




*/
SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
   void(*xProfile)(void*,const char*,sqlite3_uint64), void*);

/*
** CAPI3REF: Query Progress Callbacks
**
** ^This routine configures a callback function - the
** progress callback - that is invoked periodically during long
** running calls to [sqlite3_exec()], [sqlite3_step()] and
** [sqlite3_get_table()].  An example use for this
** interface is to keep a GUI updated during a large query.
**
** ^If the progress callback returns non-zero, the operation is
** interrupted.  This feature can be used to implement a
** "Cancel" button on a GUI progress dialog box.
**
** The progress handler must not do anything that will modify
** the database connection that invoked the progress handler.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**



*/
void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);

/*
** CAPI3REF: Opening A New Database Connection
**
** ^These routines open an SQLite database file whose name is given by the
** filename argument. ^The filename argument is interpreted as UTF-8 for
** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
** order for sqlite3_open16(). ^(A [database connection] handle is usually
** returned in *ppDb, even if an error occurs.  The only exception is that
** if SQLite is unable to allocate memory to hold the [sqlite3] object,
** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
** object.)^ ^(If the database is opened (and/or created) successfully, then
** [SQLITE_OK] is returned.  Otherwise an [error code] is returned.)^ ^The
** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
** an English language description of the error following a failure of any
** of the sqlite3_open() routines.
**
** ^The default encoding for the database will be UTF-8 if
** sqlite3_open() or sqlite3_open_v2() is called and
** UTF-16 in the native byte order if sqlite3_open16() is used.
**
** Whether or not an error occurs when it is opened, resources
** associated with the [database connection] handle should be released by
** passing it to [sqlite3_close()] when it is no longer required.
**
** The sqlite3_open_v2() interface works like sqlite3_open()
** except that it accepts two additional parameters for additional control
** over the new database connection.  ^(The flags parameter to
** sqlite3_open_v2() can take one of
** the following three values, optionally combined with the 
** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
** and/or [SQLITE_OPEN_PRIVATECACHE] flags:)^
**
** <dl>
** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
** <dd>The database is opened in read-only mode.  If the database does not
** already exist, an error is returned.</dd>)^
**
** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
** <dd>The database is opened for reading and writing if possible, or reading
** only if the file is write protected by the operating system.  In either
** case the database must already exist, otherwise an error is returned.</dd>)^
**
** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
** <dd>The database is opened for reading and writing, and is creates it if
** it does not already exist. This is the behavior that is always used for
** sqlite3_open() and sqlite3_open16().</dd>)^
** </dl>
**
** If the 3rd parameter to sqlite3_open_v2() is not one of the
** combinations shown above or one of the combinations shown above combined
** with the [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX],
** [SQLITE_OPEN_SHAREDCACHE] and/or [SQLITE_OPEN_SHAREDCACHE] flags,
** then the behavior is undefined.
**
** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
** opens in the multi-thread [threading mode] as long as the single-thread
** mode has not been set at compile-time or start-time.  ^If the
** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
** in the serialized [threading mode] unless single-thread was
** previously selected at compile-time or start-time.
** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
** eligible to use [shared cache mode], regardless of whether or not shared
** cache is enabled using [sqlite3_enable_shared_cache()].  ^The
** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
** participate in [shared cache mode] even if it is enabled.
**
** ^If the filename is ":memory:", then a private, temporary in-memory database
** is created for the connection.  ^This in-memory database will vanish when
** the database connection is closed.  Future versions of SQLite might
** make use of additional special filenames that begin with the ":" character.
** It is recommended that when a database filename actually does begin with
** a ":" character you should prefix the filename with a pathname such as
** "./" to avoid ambiguity.
**
** ^If the filename is an empty string, then a private, temporary
** on-disk database will be created.  ^This private database will be
** automatically deleted as soon as the database connection is closed.
**
** ^The fourth parameter to sqlite3_open_v2() is the name of the
** [sqlite3_vfs] object that defines the operating system interface that
** the new database connection should use.  ^If the fourth parameter is
** a NULL pointer then the default [sqlite3_vfs] object is used.
**
** <b>Note to Windows users:</b>  The encoding used for the filename argument
** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
** codepage is currently defined.  Filenames containing international
** characters must be converted to UTF-8 prior to passing them into
** sqlite3_open() or sqlite3_open_v2().




*/
int sqlite3_open(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb          /* OUT: SQLite db handle */
);
int sqlite3_open16(
  const void *filename,   /* Database filename (UTF-16) */
................................................................................
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  int flags,              /* Flags */
  const char *zVfs        /* Name of VFS module to use */
);

/*
** CAPI3REF: Error Codes And Messages
**
** ^The sqlite3_errcode() interface returns the numeric [result code] or
** [extended result code] for the most recent failed sqlite3_* API call
** associated with a [database connection]. If a prior API call failed
** but the most recent API call succeeded, the return value from
** sqlite3_errcode() is undefined.  ^The sqlite3_extended_errcode()
** interface is the same except that it always returns the 
** [extended result code] even when extended result codes are
** disabled.
**
** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
** text that describes the error, as either UTF-8 or UTF-16 respectively.
** ^(Memory to hold the error message string is managed internally.
** The application does not need to worry about freeing the result.
** However, the error string might be overwritten or deallocated by
** subsequent calls to other SQLite interface functions.)^
**
** When the serialized [threading mode] is in use, it might be the
** case that a second error occurs on a separate thread in between
** the time of the first error and the call to these interfaces.
** When that happens, the second error will be reported since these
** interfaces always report the most recent result.  To avoid
** this, each thread can obtain exclusive use of the [database connection] D
................................................................................
** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
** all calls to the interfaces listed here are completed.
**
** If an interface fails with SQLITE_MISUSE, that means the interface
** was invoked incorrectly by the application.  In that case, the
** error code and message may or may not be set.



*/
int sqlite3_errcode(sqlite3 *db);
int sqlite3_extended_errcode(sqlite3 *db);
const char *sqlite3_errmsg(sqlite3*);
const void *sqlite3_errmsg16(sqlite3*);

/*
** CAPI3REF: SQL Statement Object
** KEYWORDS: {prepared statement} {prepared statements}
**
** An instance of this object represents a single SQL statement.
** This object is variously known as a "prepared statement" or a
** "compiled SQL statement" or simply as a "statement".
**
** The life of a statement object goes something like this:
................................................................................
**
** Refer to documentation on individual methods above for additional
** information.
*/
typedef struct sqlite3_stmt sqlite3_stmt;

/*
** CAPI3REF: Run-time Limits
**
** ^(This interface allows the size of various constructs to be limited
** on a connection by connection basis.  The first parameter is the
** [database connection] whose limit is to be set or queried.  The
** second parameter is one of the [limit categories] that define a
** class of constructs to be size limited.  The third parameter is the
** new limit for that construct.  The function returns the old limit.)^
**
** ^If the new limit is a negative number, the limit is unchanged.
** ^(For the limit category of SQLITE_LIMIT_XYZ there is a 
** [limits | hard upper bound]
** set by a compile-time C preprocessor macro named 
** [limits | SQLITE_MAX_XYZ].
** (The "_LIMIT_" in the name is changed to "_MAX_".))^
** ^Attempts to increase a limit above its hard upper bound are
** silently truncated to the hard upper bound.
**
** Run-time limits are intended for use in applications that manage
** both their own internal database and also databases that are controlled
** by untrusted external sources.  An example application might be a
** web browser that has its own databases for storing history and
** separate databases controlled by JavaScript applications downloaded
** off the Internet.  The internal databases can be given the
** large, default limits.  Databases managed by external sources can
** be given much smaller limits designed to prevent a denial of service
** attack.  Developers might also want to use the [sqlite3_set_authorizer()]
** interface to further control untrusted SQL.  The size of the database
** created by an untrusted script can be contained using the
** [max_page_count] [PRAGMA].
**
** New run-time limit categories may be added in future releases.



*/
int sqlite3_limit(sqlite3*, int id, int newVal);

/*
** CAPI3REF: Run-Time Limit Categories
** KEYWORDS: {limit category} {*limit categories}
**
** These constants define various performance limits
** that can be lowered at run-time using [sqlite3_limit()].
** The synopsis of the meanings of the various limits is shown below.
** Additional information is available at [limits | Limits in SQLite].
**
** <dl>
** ^(<dt>SQLITE_LIMIT_LENGTH</dt>
** <dd>The maximum size of any string or BLOB or table row.<dd>)^
**
** ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_COLUMN</dt>
** <dd>The maximum number of columns in a table definition or in the
** result set of a [SELECT] or the maximum number of columns in an index
** or in an ORDER BY or GROUP BY clause.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
** <dd>The maximum depth of the parse tree on any expression.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
** <dd>The maximum number of instructions in a virtual machine program
** used to implement an SQL statement.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
** <dd>The maximum number of arguments on a function.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
**
** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
** <dd>The maximum length of the pattern argument to the [LIKE] or
** [GLOB] operators.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
** <dd>The maximum number of variables in an SQL statement that can
** be bound.</dd>)^
**
** ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
** <dd>The maximum depth of recursion for triggers.</dd>)^
** </dl>
*/
#define SQLITE_LIMIT_LENGTH                    0
#define SQLITE_LIMIT_SQL_LENGTH                1
#define SQLITE_LIMIT_COLUMN                    2
#define SQLITE_LIMIT_EXPR_DEPTH                3
#define SQLITE_LIMIT_COMPOUND_SELECT           4
................................................................................
#define SQLITE_LIMIT_FUNCTION_ARG              6
#define SQLITE_LIMIT_ATTACHED                  7
#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH       8
#define SQLITE_LIMIT_VARIABLE_NUMBER           9
#define SQLITE_LIMIT_TRIGGER_DEPTH            10

/*
** CAPI3REF: Compiling An SQL Statement
** KEYWORDS: {SQL statement compiler}
**
** To execute an SQL query, it must first be compiled into a byte-code
** program using one of these routines.
**
** The first argument, "db", is a [database connection] obtained from a
** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
................................................................................
** [sqlite3_open16()].  The database connection must not have been closed.
**
** The second argument, "zSql", is the statement to be compiled, encoded
** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
** use UTF-16.
**
** ^If the nByte argument is less than zero, then zSql is read up to the
** first zero terminator. ^If nByte is non-negative, then it is the maximum
** number of  bytes read from zSql.  ^When nByte is non-negative, the
** zSql string ends at either the first '\000' or '\u0000' character or
** the nByte-th byte, whichever comes first. If the caller knows
** that the supplied string is nul-terminated, then there is a small
** performance advantage to be gained by passing an nByte parameter that
** is equal to the number of bytes in the input string <i>including</i>
** the nul-terminator bytes.
**
** ^If pzTail is not NULL then *pzTail is made to point to the first byte
** past the end of the first SQL statement in zSql.  These routines only
** compile the first statement in zSql, so *pzTail is left pointing to
** what remains uncompiled.
**
** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
** executed using [sqlite3_step()].  ^If there is an error, *ppStmt is set
** to NULL.  ^If the input text contains no SQL (if the input is an empty
** string or a comment) then *ppStmt is set to NULL.
** The calling procedure is responsible for deleting the compiled
** SQL statement using [sqlite3_finalize()] after it has finished with it.
** ppStmt may not be NULL.
**
** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
** otherwise an [error code] is returned.
**
** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
** recommended for all new programs. The two older interfaces are retained
** for backwards compatibility, but their use is discouraged.
** ^In the "v2" interfaces, the prepared statement
** that is returned (the [sqlite3_stmt] object) contains a copy of the
** original SQL text. This causes the [sqlite3_step()] interface to
** behave differently in three ways:
**
** <ol>
** <li>
** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
** always used to do, [sqlite3_step()] will automatically recompile the SQL
** statement and try to run it again.  ^If the schema has changed in
** a way that makes the statement no longer valid, [sqlite3_step()] will still
** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is
** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the
** error go away.  Note: use [sqlite3_errmsg()] to find the text
** of the parsing error that results in an [SQLITE_SCHEMA] return.
** </li>
**
** <li>
** ^When an error occurs, [sqlite3_step()] will return one of the detailed
** [error codes] or [extended error codes].  ^The legacy behavior was that
** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
** and the application would have to make a second call to [sqlite3_reset()]
** in order to find the underlying cause of the problem. With the "v2" prepare
** interfaces, the underlying reason for the error is returned immediately.
** </li>
**
** <li>
** ^If the value of a [parameter | host parameter] in the WHERE clause might
** change the query plan for a statement, then the statement may be
** automatically recompiled (as if there had been a schema change) on the first 
** [sqlite3_step()] call following any change to the 
** [sqlite3_bind_text | bindings] of the [parameter]. 
** </li>
** </ol>




*/
int sqlite3_prepare(
  sqlite3 *db,            /* Database handle */
  const char *zSql,       /* SQL statement, UTF-8 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
................................................................................
  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nByte,              /* Maximum length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);

/*
** CAPI3REF: Retrieving Statement SQL
**
** ^This interface can be used to retrieve a saved copy of the original
** SQL text used to create a [prepared statement] if that statement was
** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].



*/
const char *sqlite3_sql(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Dynamically Typed Value Object
** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
**
** SQLite uses the sqlite3_value object to represent all values
** that can be stored in a database table. SQLite uses dynamic typing
** for the values it stores.  ^Values stored in sqlite3_value objects
** can be integers, floating point values, strings, BLOBs, or NULL.
**
** An sqlite3_value object may be either "protected" or "unprotected".
** Some interfaces require a protected sqlite3_value.  Other interfaces
** will accept either a protected or an unprotected sqlite3_value.
** Every interface that accepts sqlite3_value arguments specifies
** whether or not it requires a protected sqlite3_value.
................................................................................
** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
** then there is no distinction between protected and unprotected
** sqlite3_value objects and they can be used interchangeably.  However,
** for maximum code portability it is recommended that applications
** still make the distinction between between protected and unprotected
** sqlite3_value objects even when not strictly required.
**
** ^The sqlite3_value objects that are passed as parameters into the
** implementation of [application-defined SQL functions] are protected.
** ^The sqlite3_value object returned by
** [sqlite3_column_value()] is unprotected.
** Unprotected sqlite3_value objects may only be used with
** [sqlite3_result_value()] and [sqlite3_bind_value()].
** The [sqlite3_value_blob | sqlite3_value_type()] family of
** interfaces require protected sqlite3_value objects.
*/
typedef struct Mem sqlite3_value;

/*
** CAPI3REF: SQL Function Context Object
**
** The context in which an SQL function executes is stored in an
** sqlite3_context object.  ^A pointer to an sqlite3_context object
** is always first parameter to [application-defined SQL functions].
** The application-defined SQL function implementation will pass this
** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
** [sqlite3_aggregate_context()], [sqlite3_user_data()],
** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
** and/or [sqlite3_set_auxdata()].
*/
typedef struct sqlite3_context sqlite3_context;

/*
** CAPI3REF: Binding Values To Prepared Statements
** KEYWORDS: {host parameter} {host parameters} {host parameter name}
** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
**
** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
** literals may be replaced by a [parameter] that matches one of following
** templates:
**
** <ul>
** <li>  ?
** <li>  ?NNN
** <li>  :VVV
** <li>  @VVV
** <li>  $VVV
** </ul>
**
** In the templates above, NNN represents an integer literal,
** and VVV represents an alphanumeric identifer.)^  ^The values of these
** parameters (also called "host parameter names" or "SQL parameters")
** can be set using the sqlite3_bind_*() routines defined here.
**
** ^The first argument to the sqlite3_bind_*() routines is always
** a pointer to the [sqlite3_stmt] object returned from
** [sqlite3_prepare_v2()] or its variants.
**
** ^The second argument is the index of the SQL parameter to be set.
** ^The leftmost SQL parameter has an index of 1.  ^When the same named
** SQL parameter is used more than once, second and subsequent
** occurrences have the same index as the first occurrence.
** ^The index for named parameters can be looked up using the
** [sqlite3_bind_parameter_index()] API if desired.  ^The index
** for "?NNN" parameters is the value of NNN.
** ^The NNN value must be between 1 and the [sqlite3_limit()]
** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
**
** ^The third argument is the value to bind to the parameter.
**
** ^(In those routines that have a fourth argument, its value is the
** number of bytes in the parameter.  To be clear: the value is the
** number of <u>bytes</u> in the value, not the number of characters.)^
** ^If the fourth parameter is negative, the length of the string is
** the number of bytes up to the first zero terminator.
**
** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
** string after SQLite has finished with it. ^If the fifth argument is
** the special value [SQLITE_STATIC], then SQLite assumes that the
** information is in static, unmanaged space and does not need to be freed.
** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
** SQLite makes its own private copy of the data immediately, before
** the sqlite3_bind_*() routine returns.
**
** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
** is filled with zeroes.  ^A zeroblob uses a fixed amount of memory
** (just an integer to hold its size) while it is being processed.
** Zeroblobs are intended to serve as placeholders for BLOBs whose
** content is later written using
** [sqlite3_blob_open | incremental BLOB I/O] routines.
** ^A negative value for the zeroblob results in a zero-length BLOB.
**
** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
** for the [prepared statement] or with a prepared statement for which
** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
** then the call will return [SQLITE_MISUSE].  If any sqlite3_bind_()
** routine is passed a [prepared statement] that has been finalized, the
** result is undefined and probably harmful.
**
** ^Bindings are not cleared by the [sqlite3_reset()] routine.
** ^Unbound parameters are interpreted as NULL.
**
** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
** [error code] if anything goes wrong.
** ^[SQLITE_RANGE] is returned if the parameter
** index is out of range.  ^[SQLITE_NOMEM] is returned if malloc() fails.

**
** See also: [sqlite3_bind_parameter_count()],
** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].





*/
int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
int sqlite3_bind_double(sqlite3_stmt*, int, double);
int sqlite3_bind_int(sqlite3_stmt*, int, int);
int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
int sqlite3_bind_null(sqlite3_stmt*, int);
int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);

/*
** CAPI3REF: Number Of SQL Parameters
**
** ^This routine can be used to find the number of [SQL parameters]
** in a [prepared statement].  SQL parameters are tokens of the
** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
** placeholders for values that are [sqlite3_bind_blob | bound]
** to the parameters at a later time.
**
** ^(This routine actually returns the index of the largest (rightmost)
** parameter. For all forms except ?NNN, this will correspond to the
** number of unique parameters.  If parameters of the ?NNN form are used,
** there may be gaps in the list.)^
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_name()], and
** [sqlite3_bind_parameter_index()].



*/
int sqlite3_bind_parameter_count(sqlite3_stmt*);

/*
** CAPI3REF: Name Of A Host Parameter
**
** ^The sqlite3_bind_parameter_name(P,N) interface returns
** the name of the N-th [SQL parameter] in the [prepared statement] P.
** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
** respectively.
** In other words, the initial ":" or "$" or "@" or "?"
** is included as part of the name.)^
** ^Parameters of the form "?" without a following integer have no name
** and are referred to as "nameless" or "anonymous parameters".
**
** ^The first host parameter has an index of 1, not 0.
**
** ^If the value N is out of range or if the N-th parameter is
** nameless, then NULL is returned.  ^The returned string is
** always in UTF-8 encoding even if the named parameter was
** originally specified as UTF-16 in [sqlite3_prepare16()] or
** [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].



*/
const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);

/*
** CAPI3REF: Index Of A Parameter With A Given Name
**
** ^Return the index of an SQL parameter given its name.  ^The
** index value returned is suitable for use as the second
** parameter to [sqlite3_bind_blob|sqlite3_bind()].  ^A zero
** is returned if no matching parameter is found.  ^The parameter
** name must be given in UTF-8 even if the original statement
** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
**
** See also: [sqlite3_bind_blob|sqlite3_bind()],
** [sqlite3_bind_parameter_count()], and
** [sqlite3_bind_parameter_index()].



*/
int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);

/*
** CAPI3REF: Reset All Bindings On A Prepared Statement
**
** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
** the [sqlite3_bind_blob | bindings] on a [prepared statement].
** ^Use this routine to reset all host parameters to NULL.



*/
int sqlite3_clear_bindings(sqlite3_stmt*);

/*
** CAPI3REF: Number Of Columns In A Result Set
**
** ^Return the number of columns in the result set returned by the
** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
** statement that does not return data (for example an [UPDATE]).



*/
int sqlite3_column_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Column Names In A Result Set
**
** ^These routines return the name assigned to a particular column
** in the result set of a [SELECT] statement.  ^The sqlite3_column_name()
** interface returns a pointer to a zero-terminated UTF-8 string
** and sqlite3_column_name16() returns a pointer to a zero-terminated
** UTF-16 string.  ^The first parameter is the [prepared statement]
** that implements the [SELECT] statement. ^The second parameter is the
** column number.  ^The leftmost column is number 0.
**
** ^The returned string pointer is valid until either the [prepared statement]
** is destroyed by [sqlite3_finalize()] or until the next call to
** sqlite3_column_name() or sqlite3_column_name16() on the same column.
**
** ^If sqlite3_malloc() fails during the processing of either routine
** (for example during a conversion from UTF-8 to UTF-16) then a
** NULL pointer is returned.
**
** ^The name of a result column is the value of the "AS" clause for
** that column, if there is an AS clause.  If there is no AS clause
** then the name of the column is unspecified and may change from
** one release of SQLite to the next.



*/
const char *sqlite3_column_name(sqlite3_stmt*, int N);
const void *sqlite3_column_name16(sqlite3_stmt*, int N);

/*
** CAPI3REF: Source Of Data In A Query Result
**
** ^These routines provide a means to determine the database, table, and
** table column that is the origin of a particular result column in
** [SELECT] statement.
** ^The name of the database or table or column can be returned as
** either a UTF-8 or UTF-16 string.  ^The _database_ routines return
** the database name, the _table_ routines return the table name, and
** the origin_ routines return the column name.
** ^The returned string is valid until the [prepared statement] is destroyed
** using [sqlite3_finalize()] or until the same information is requested
** again in a different encoding.
**
** ^The names returned are the original un-aliased names of the
** database, table, and column.
**
** ^The first argument to these interfaces is a [prepared statement].
** ^These functions return information about the Nth result column returned by
** the statement, where N is the second function argument.
** ^The left-most column is column 0 for these routines.
**
** ^If the Nth column returned by the statement is an expression or
** subquery and is not a column value, then all of these functions return
** NULL.  ^These routine might also return NULL if a memory allocation error
** occurs.  ^Otherwise, they return the name of the attached database, table,
** or column that query result column was extracted from.
**
** ^As with all other SQLite APIs, those whose names end with "16" return
** UTF-16 encoded strings and the other functions return UTF-8.
**
** ^These APIs are only available if the library was compiled with the
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
**

** If two or more threads call one or more of these routines against the same
** prepared statement and column at the same time then the results are
** undefined.
**



** If two or more threads call one or more
** [sqlite3_column_database_name | column metadata interfaces]
** for the same [prepared statement] and result column
** at the same time then the results are undefined.
*/
const char *sqlite3_column_database_name(sqlite3_stmt*,int);
const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
const char *sqlite3_column_table_name(sqlite3_stmt*,int);
const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);

/*
** CAPI3REF: Declared Datatype Of A Query Result
**
** ^(The first parameter is a [prepared statement].
** If this statement is a [SELECT] statement and the Nth column of the
** returned result set of that [SELECT] is a table column (not an
** expression or subquery) then the declared type of the table
** column is returned.)^  ^If the Nth column of the result set is an
** expression or subquery, then a NULL pointer is returned.
** ^The returned string is always UTF-8 encoded.
**
** ^(For example, given the database schema:
**
** CREATE TABLE t1(c1 VARIANT);
**
** and the following statement to be compiled:
**
** SELECT c1 + 1, c1 FROM t1;
**
** this routine would return the string "VARIANT" for the second result
** column (i==1), and a NULL pointer for the first result column (i==0).)^
**
** ^SQLite uses dynamic run-time typing.  ^So just because a column
** is declared to contain a particular type does not mean that the
** data stored in that column is of the declared type.  SQLite is
** strongly typed, but the typing is dynamic not static.  ^Type
** is associated with individual values, not with the containers
** used to hold those values.



*/
const char *sqlite3_column_decltype(sqlite3_stmt*,int);
const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

/*
** CAPI3REF: Evaluate An SQL Statement
**
** After a [prepared statement] has been prepared using either
** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
** must be called one or more times to evaluate the statement.
**
** The details of the behavior of the sqlite3_step() interface depend
** on whether the statement was prepared using the newer "v2" interface
** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
** new "v2" interface is recommended for new applications but the legacy
** interface will continue to be supported.
**
** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
** ^With the "v2" interface, any of the other [result codes] or
** [extended result codes] might be returned as well.
**
** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
** database locks it needs to do its job.  ^If the statement is a [COMMIT]
** or occurs outside of an explicit transaction, then you can retry the
** statement.  If the statement is not a [COMMIT] and occurs within a
** explicit transaction then you should rollback the transaction before
** continuing.
**
** ^[SQLITE_DONE] means that the statement has finished executing
** successfully.  sqlite3_step() should not be called again on this virtual
** machine without first calling [sqlite3_reset()] to reset the virtual
** machine back to its initial state.
**
** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
** is returned each time a new row of data is ready for processing by the
** caller. The values may be accessed using the [column access functions].
** sqlite3_step() is called again to retrieve the next row of data.
**
** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
** violation) has occurred.  sqlite3_step() should not be called again on
** the VM. More information may be found by calling [sqlite3_errmsg()].
** ^With the legacy interface, a more specific error code (for example,
** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
** can be obtained by calling [sqlite3_reset()] on the
** [prepared statement].  ^In the "v2" interface,
** the more specific error code is returned directly by sqlite3_step().
**
** [SQLITE_MISUSE] means that the this routine was called inappropriately.
** Perhaps it was called on a [prepared statement] that has
** already been [sqlite3_finalize | finalized] or on one that had
** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
** be the case that the same database connection is being used by two or
................................................................................
** specific [error codes] that better describes the error.
** We admit that this is a goofy design.  The problem has been fixed
** with the "v2" interface.  If you prepare all of your SQL statements
** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
** then the more specific [error codes] are returned directly
** by sqlite3_step().  The use of the "v2" interface is recommended.



*/
int sqlite3_step(sqlite3_stmt*);

/*
** CAPI3REF: Number of columns in a result set
**
** ^The sqlite3_data_count(P) the number of columns in the
** of the result set of [prepared statement] P.


*/
int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Fundamental Datatypes
** KEYWORDS: SQLITE_TEXT
**
** ^(Every value in SQLite has one of five fundamental datatypes:
**
** <ul>
** <li> 64-bit signed integer
** <li> 64-bit IEEE floating point number
** <li> string
** <li> BLOB
** <li> NULL
** </ul>)^
**
** These constants are codes for each of those types.
**
** Note that the SQLITE_TEXT constant was also used in SQLite version 2
** for a completely different meaning.  Software that links against both
** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
** SQLITE_TEXT.
................................................................................
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3

/*
** CAPI3REF: Result Values From A Query
** KEYWORDS: {column access functions}
**
** These routines form the "result set" interface.
**
** ^These routines return information about a single column of the current
** result row of a query.  ^In every case the first argument is a pointer
** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
** that was returned from [sqlite3_prepare_v2()] or one of its variants)
** and the second argument is the index of the column for which information
** should be returned. ^The leftmost column of the result set has the index 0.
** ^The number of columns in the result can be determined using
** [sqlite3_column_count()].
**
** If the SQL statement does not currently point to a valid row, or if the
** column index is out of range, the result is undefined.
** These routines may only be called when the most recent call to
** [sqlite3_step()] has returned [SQLITE_ROW] and neither
** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
................................................................................
** If any of these routines are called after [sqlite3_reset()] or
** [sqlite3_finalize()] or after [sqlite3_step()] has returned
** something other than [SQLITE_ROW], the results are undefined.
** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
** are called from a different thread while any of these routines
** are pending, then the results are undefined.
**
** ^The sqlite3_column_type() routine returns the
** [SQLITE_INTEGER | datatype code] for the initial data type
** of the result column.  ^The returned value is one of [SQLITE_INTEGER],
** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
** returned by sqlite3_column_type() is only meaningful if no type
** conversions have occurred as described below.  After a type conversion,
** the value returned by sqlite3_column_type() is undefined.  Future
** versions of SQLite may change the behavior of sqlite3_column_type()
** following a type conversion.
**
** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
** routine returns the number of bytes in that BLOB or string.
** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
** the string to UTF-8 and then returns the number of bytes.
** ^If the result is a numeric value then sqlite3_column_bytes() uses
** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
** the number of bytes in that string.
** ^The value returned does not include the zero terminator at the end
** of the string.  ^For clarity: the value returned is the number of
** bytes in the string, not the number of characters.
**
** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
** even empty strings, are always zero terminated.  ^The return
** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary
** pointer, possibly even a NULL pointer.
**
** ^The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
** but leaves the result in UTF-16 in native byte order instead of UTF-8.
** ^The zero terminator is not included in this count.
**
** ^The object returned by [sqlite3_column_value()] is an
** [unprotected sqlite3_value] object.  An unprotected sqlite3_value object
** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()].
** If the [unprotected sqlite3_value] object returned by
** [sqlite3_column_value()] is used in any other way, including calls
** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
** or [sqlite3_value_bytes()], then the behavior is undefined.
**
** These routines attempt to convert the value where appropriate.  ^For
** example, if the internal representation is FLOAT and a text result
** is requested, [sqlite3_snprintf()] is used internally to perform the
** conversion automatically.  ^(The following table details the conversions
** that are applied:
**
** <blockquote>
** <table border="1">
** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
**
** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
................................................................................
** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
** <tr><td>  TEXT    <td>   BLOB    <td> No change
** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
** </table>
** </blockquote>)^
**
** The table above makes reference to standard C library functions atoi()
** and atof().  SQLite does not really use these functions.  It has its
** own equivalent internal routines.  The atoi() and atof() names are
** used in the table for brevity and because they are familiar to most
** C programmers.
**
** ^Note that when type conversions occur, pointers returned by prior
** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
** sqlite3_column_text16() may be invalidated.
** ^(Type conversions and pointer invalidations might occur
** in the following cases:
**
** <ul>
** <li> The initial content is a BLOB and sqlite3_column_text() or
**      sqlite3_column_text16() is called.  A zero-terminator might
**      need to be added to the string.</li>
** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
**      sqlite3_column_text16() is called.  The content must be converted
**      to UTF-16.</li>
** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
**      sqlite3_column_text() is called.  The content must be converted
**      to UTF-8.</li>
** </ul>)^
**
** ^Conversions between UTF-16be and UTF-16le are always done in place and do
** not invalidate a prior pointer, though of course the content of the buffer
** that the prior pointer points to will have been modified.  Other kinds
** of conversion are done in place when it is possible, but sometimes they
** are not possible and in those cases prior pointers are invalidated.
**
** ^(The safest and easiest to remember policy is to invoke these routines
** in one of the following ways:
**
** <ul>
**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
** </ul>)^
**
** In other words, you should call sqlite3_column_text(),
** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
** into the desired format, then invoke sqlite3_column_bytes() or
** sqlite3_column_bytes16() to find the size of the result.  Do not mix calls
** to sqlite3_column_text() or sqlite3_column_blob() with calls to
** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
** with calls to sqlite3_column_bytes().
**
** ^The pointers returned are valid until a type conversion occurs as
** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
** [sqlite3_finalize()] is called.  ^The memory space used to hold strings
** and BLOBs is freed automatically.  Do <b>not</b> pass the pointers returned
** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
** [sqlite3_free()].
**
** ^(If a memory allocation error occurs during the evaluation of any
** of these routines, a default value is returned.  The default value
** is either the integer 0, the floating point number 0.0, or a NULL
** pointer.  Subsequent calls to [sqlite3_errcode()] will return
** [SQLITE_NOMEM].)^




*/
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);
int sqlite3_column_int(sqlite3_stmt*, int iCol);
sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
int sqlite3_column_type(sqlite3_stmt*, int iCol);
sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

/*
** CAPI3REF: Destroy A Prepared Statement Object
**
** ^The sqlite3_finalize() function is called to delete a [prepared statement].
** ^If the statement was executed successfully or not executed at all, then
** SQLITE_OK is returned. ^If execution of the statement failed then an
** [error code] or [extended error code] is returned.
**
** ^This routine can be called at any point during the execution of the
** [prepared statement].  ^If the virtual machine has not
** completed execution when this routine is called, that is like
** encountering an error or an [sqlite3_interrupt | interrupt].
** ^Incomplete updates may be rolled back and transactions canceled,
** depending on the circumstances, and the
** [error code] returned will be [SQLITE_ABORT].



*/
int sqlite3_finalize(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Reset A Prepared Statement Object
**
** The sqlite3_reset() function is called to reset a [prepared statement]
** object back to its initial state, ready to be re-executed.
** ^Any SQL statement variables that had values bound to them using
** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
** Use [sqlite3_clear_bindings()] to reset the bindings.
**
** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
** back to the beginning of its program.
**
** ^If the most recent call to [sqlite3_step(S)] for the
** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
** or if [sqlite3_step(S)] has never before been called on S,
** then [sqlite3_reset(S)] returns [SQLITE_OK].
**
** ^If the most recent call to [sqlite3_step(S)] for the
** [prepared statement] S indicated an error, then
** [sqlite3_reset(S)] returns an appropriate [error code].
**
** ^The [sqlite3_reset(S)] interface does not change the values
** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
*/
int sqlite3_reset(sqlite3_stmt *pStmt);

/*
** CAPI3REF: Create Or Redefine SQL Functions
** KEYWORDS: {function creation routines}
** KEYWORDS: {application-defined SQL function}
** KEYWORDS: {application-defined SQL functions}
**
** ^These two functions (collectively known as "function creation routines")
** are used to add SQL functions or aggregates or to redefine the behavior
** of existing SQL functions or aggregates.  The only difference between the
** two is that the second parameter, the name of the (scalar) function or
** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16
** for sqlite3_create_function16().
**
** ^The first parameter is the [database connection] to which the SQL
** function is to be added.  ^If an application uses more than one database
** connection then application-defined SQL functions must be added
** to each database connection separately.
**
** The second parameter is the name of the SQL function to be created or
** redefined.  ^The length of the name is limited to 255 bytes, exclusive of
** the zero-terminator.  Note that the name length limit is in bytes, not
** characters.  ^Any attempt to create a function with a longer name
** will result in [SQLITE_ERROR] being returned.
**
** ^The third parameter (nArg)
** is the number of arguments that the SQL function or
** aggregate takes. ^If this parameter is -1, then the SQL function or
** aggregate may take any number of arguments between 0 and the limit
** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]).  If the third
** parameter is less than -1 or greater than 127 then the behavior is
** undefined.
**
** The fourth parameter, eTextRep, specifies what
** [SQLITE_UTF8 | text encoding] this SQL function prefers for
** its parameters.  Any SQL function implementation should be able to work
** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
** more efficient with one encoding than another.  ^An application may
** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
** times with the same function but with different values of eTextRep.
** ^When multiple implementations of the same function are available, SQLite
** will pick the one that involves the least amount of data conversion.
** If there is only a single implementation which does not care what text
** encoding is used, then the fourth argument should be [SQLITE_ANY].
**
** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
** function can gain access to this pointer using [sqlite3_user_data()].)^
**
** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** pointers to C-language functions that implement the SQL function or
** aggregate. ^A scalar SQL function requires an implementation of the xFunc
** callback only; NULL pointers should be passed as the xStep and xFinal
** parameters. ^An aggregate SQL function requires an implementation of xStep
** and xFinal and NULL should be passed for xFunc. ^To delete an existing
** SQL function or aggregate, pass NULL for all three function callbacks.
**
** ^It is permitted to register multiple implementations of the same
** functions with the same name but with either differing numbers of
** arguments or differing preferred text encodings.  ^SQLite will use
** the implementation that most closely matches the way in which the
** SQL function is used.  ^A function implementation with a non-negative
** nArg parameter is a better match than a function implementation with
** a negative nArg.  ^A function where the preferred text encoding
** matches the database encoding is a better
** match than a function where the encoding is different.  
** ^A function where the encoding difference is between UTF16le and UTF16be
** is a closer match than a function where the encoding difference is
** between UTF8 and UTF16.
**
** ^Built-in functions may be overloaded by new application-defined functions.
** ^The first application-defined function with a given name overrides all
** built-in functions in the same [database connection] with the same name.
** ^Subsequent application-defined functions of the same name only override 
** prior application-defined functions that are an exact match for the
** number of parameters and preferred encoding.
**
** ^An application-defined function is permitted to call other
** SQLite interfaces.  However, such calls must not
** close the database connection nor finalize or reset the prepared
** statement in which the function is running.




*/
int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,
................................................................................
  void *pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);

/*
** CAPI3REF: Text Encodings
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.
*/
#define SQLITE_UTF8           1
#define SQLITE_UTF16LE        2
#define SQLITE_UTF16BE        3
................................................................................
SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
SQLITE_DEPRECATED int sqlite3_global_recover(void);
SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64);
#endif

/*
** CAPI3REF: Obtaining SQL Function Parameter Values
**
** The C-language implementation of SQL functions and aggregates uses
** this set of interface routines to access the parameter values on
** the function or aggregate.
**
** The xFunc (for scalar functions) or xStep (for aggregates) parameters
** to [sqlite3_create_function()] and [sqlite3_create_function16()]
................................................................................
** each parameter to the SQL function.  These routines are used to
** extract values from the [sqlite3_value] objects.
**
** These routines work only with [protected sqlite3_value] objects.
** Any attempt to use these routines on an [unprotected sqlite3_value]
** object results in undefined behavior.
**
** ^These routines work just like the corresponding [column access functions]
** except that  these routines take a single [protected sqlite3_value] object
** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
**
** ^The sqlite3_value_text16() interface extracts a UTF-16 string
** in the native byte-order of the host machine.  ^The
** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
** extract UTF-16 strings as big-endian and little-endian respectively.
**
** ^(The sqlite3_value_numeric_type() interface attempts to apply
** numeric affinity to the value.  This means that an attempt is
** made to convert the value to an integer or floating point.  If
** such a conversion is possible without loss of information (in other
** words, if the value is a string that looks like a number)
** then the conversion is performed.  Otherwise no conversion occurs.
** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
**
** Please pay particular attention to the fact that the pointer returned
** from [sqlite3_value_blob()], [sqlite3_value_text()], or
** [sqlite3_value_text16()] can be invalidated by a subsequent call to
** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
** or [sqlite3_value_text16()].
**
** These routines must be called from the same thread as
** the SQL function that supplied the [sqlite3_value*] parameters.




*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
................................................................................
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** CAPI3REF: Obtain Aggregate Function Context
**
** Implementions of aggregate SQL functions use this
** routine to allocate memory for storing their state.
**
** ^The first time the sqlite3_aggregate_context(C,N) routine is called 
** for a particular aggregate function, SQLite
** allocates N of memory, zeroes out that memory, and returns a pointer
** to the new memory. ^On second and subsequent calls to
** sqlite3_aggregate_context() for the same aggregate function instance,
** the same buffer is returned.  Sqlite3_aggregate_context() is normally

** called once for each invocation of the xStep callback and then one
** last time when the xFinal callback is invoked.  ^(When no rows match
** an aggregate query, the xStep() callback of the aggregate function
** implementation is never called and xFinal() is called exactly once.
** In those cases, sqlite3_aggregate_context() might be called for the
** first time from within xFinal().)^
**
** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is
** less than or equal to zero or if a memory allocate error occurs.
**
** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
** determined by the N parameter on first successful call.  Changing the
** value of N in subsequent call to sqlite3_aggregate_context() within
** the same aggregate function instance will not resize the memory
** allocation.)^
**
** ^SQLite automatically frees the memory allocated by 

** sqlite3_aggregate_context() when the aggregate query concludes.
**
** The first parameter must be a copy of the
** [sqlite3_context | SQL function context] that is the first parameter
** to the xStep or xFinal callback routine that implements the aggregate
** function.
**
** This routine must be called from the same thread in which
** the aggregate SQL function is running.



*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** CAPI3REF: User Data For Functions
**
** ^The sqlite3_user_data() interface returns a copy of
** the pointer that was the pUserData parameter (the 5th parameter)
** of the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.
**
** This routine must be called from the same thread in which
** the application-defined function is running.



*/
void *sqlite3_user_data(sqlite3_context*);

/*
** CAPI3REF: Database Connection For Functions
**
** ^The sqlite3_context_db_handle() interface returns a copy of
** the pointer to the [database connection] (the 1st parameter)
** of the [sqlite3_create_function()]
** and [sqlite3_create_function16()] routines that originally
** registered the application defined function.



*/
sqlite3 *sqlite3_context_db_handle(sqlite3_context*);

/*
** CAPI3REF: Function Auxiliary Data
**
** The following two functions may be used by scalar SQL functions to
** associate metadata with argument values. If the same value is passed to
** multiple invocations of the same SQL function during query execution, under
** some circumstances the associated metadata may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** metadata associated with the SQL value passed as the regular expression
** pattern.  The compiled regular expression can be reused on multiple
** invocations of the same function so that the original pattern string
** does not need to be recompiled on each invocation.
**
** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
** associated by the sqlite3_set_auxdata() function with the Nth argument
** value to the application-defined function. ^If no metadata has been ever
** been set for the Nth argument of the function, or if the corresponding
** function parameter has changed since the meta-data was set,
** then sqlite3_get_auxdata() returns a NULL pointer.
**
** ^The sqlite3_set_auxdata() interface saves the metadata
** pointed to by its 3rd parameter as the metadata for the N-th
** argument of the application-defined function.  Subsequent
** calls to sqlite3_get_auxdata() might return this data, if it has
** not been destroyed.
** ^If it is not NULL, SQLite will invoke the destructor
** function given by the 4th parameter to sqlite3_set_auxdata() on
** the metadata when the corresponding function parameter changes
** or when the SQL statement completes, whichever comes first.
**
** SQLite is free to call the destructor and drop metadata on any
** parameter of any function at any time.  ^The only guarantee is that
** the destructor will be called before the metadata is dropped.
**
** ^(In practice, metadata is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and [parameters].)^
**
** These routines must be called from the same thread in which
** the SQL function is running.



*/
void *sqlite3_get_auxdata(sqlite3_context*, int N);
void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));


/*
** CAPI3REF: Constants Defining Special Destructor Behavior
**
** These are special values for the destructor that is passed in as the
** final argument to routines like [sqlite3_result_blob()].  ^If the destructor
** argument is SQLITE_STATIC, it means that the content pointer is constant
** and will never change.  It does not need to be destroyed.  ^The
** SQLITE_TRANSIENT value means that the content will likely change in
** the near future and that SQLite should make its own private copy of
** the content before returning.
**
** The typedef is necessary to work around problems in certain
** C++ compilers.  See ticket #2191.
*/
typedef void (*sqlite3_destructor_type)(void*);
#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)

/*
** CAPI3REF: Setting The Result Of An SQL Function
**
** These routines are used by the xFunc or xFinal callbacks that
** implement SQL functions and aggregates.  See
** [sqlite3_create_function()] and [sqlite3_create_function16()]
** for additional information.
**
** These functions work very much like the [parameter binding] family of
** functions used to bind values to host parameters in prepared statements.
** Refer to the [SQL parameter] documentation for additional information.
**
** ^The sqlite3_result_blob() interface sets the result from
** an application-defined function to be the BLOB whose content is pointed
** to by the second parameter and which is N bytes long where N is the
** third parameter.
**
** ^The sqlite3_result_zeroblob() interfaces set the result of
** the application-defined function to be a BLOB containing all zero
** bytes and N bytes in size, where N is the value of the 2nd parameter.
**
** ^The sqlite3_result_double() interface sets the result from
** an application-defined function to be a floating point value specified
** by its 2nd argument.
**
** ^The sqlite3_result_error() and sqlite3_result_error16() functions
** cause the implemented SQL function to throw an exception.
** ^SQLite uses the string pointed to by the
** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
** as the text of an error message.  ^SQLite interprets the error
** message string from sqlite3_result_error() as UTF-8. ^SQLite
** interprets the string from sqlite3_result_error16() as UTF-16 in native
** byte order.  ^If the third parameter to sqlite3_result_error()
** or sqlite3_result_error16() is negative then SQLite takes as the error
** message all text up through the first zero character.
** ^If the third parameter to sqlite3_result_error() or
** sqlite3_result_error16() is non-negative then SQLite takes that many
** bytes (not characters) from the 2nd parameter as the error message.
** ^The sqlite3_result_error() and sqlite3_result_error16()
** routines make a private copy of the error message text before
** they return.  Hence, the calling function can deallocate or
** modify the text after they return without harm.
** ^The sqlite3_result_error_code() function changes the error code
** returned by SQLite as a result of an error in a function.  ^By default,
** the error code is SQLITE_ERROR.  ^A subsequent call to sqlite3_result_error()
** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
**
** ^The sqlite3_result_toobig() interface causes SQLite to throw an error
** indicating that a string or BLOB is too long to represent.
**
** ^The sqlite3_result_nomem() interface causes SQLite to throw an error
** indicating that a memory allocation failed.
**
** ^The sqlite3_result_int() interface sets the return value
** of the application-defined function to be the 32-bit signed integer
** value given in the 2nd argument.
** ^The sqlite3_result_int64() interface sets the return value
** of the application-defined function to be the 64-bit signed integer
** value given in the 2nd argument.
**
** ^The sqlite3_result_null() interface sets the return value
** of the application-defined function to be NULL.
**
** ^The sqlite3_result_text(), sqlite3_result_text16(),
** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
** set the return value of the application-defined function to be
** a text string which is represented as UTF-8, UTF-16 native byte order,
** UTF-16 little endian, or UTF-16 big endian, respectively.
** ^SQLite takes the text result from the application from
** the 2nd parameter of the sqlite3_result_text* interfaces.
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
** is negative, then SQLite takes result text from the 2nd parameter
** through the first zero character.
** ^If the 3rd parameter to the sqlite3_result_text* interfaces
** is non-negative, then as many bytes (not characters) of the text
** pointed to by the 2nd parameter are taken as the application-defined
** function result.
** ^If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
** function as the destructor on the text or BLOB result when it has
** finished using that result.
** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
** assumes that the text or BLOB result is in constant space and does not
** copy the content of the parameter nor call a destructor on the content
** when it has finished using that result.
** ^If the 4th parameter to the sqlite3_result_text* interfaces
** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
** then SQLite makes a copy of the result into space obtained from
** from [sqlite3_malloc()] before it returns.
**
** ^The sqlite3_result_value() interface sets the result of
** the application-defined function to be a copy the
** [unprotected sqlite3_value] object specified by the 2nd parameter.  ^The
** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
** so that the [sqlite3_value] specified in the parameter may change or
** be deallocated after sqlite3_result_value() returns without harm.
** ^A [protected sqlite3_value] object may always be used where an
** [unprotected sqlite3_value] object is required, so either
** kind of [sqlite3_value] object can be used with this interface.
**
** If these routines are called from within the different thread
** than the one containing the application-defined function that received
** the [sqlite3_context] pointer, the results are undefined.





*/
void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_double(sqlite3_context*, double);
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);
void sqlite3_result_error_toobig(sqlite3_context*);
void sqlite3_result_error_nomem(sqlite3_context*);
................................................................................
void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
void sqlite3_result_zeroblob(sqlite3_context*, int n);

/*
** CAPI3REF: Define New Collating Sequences
**
** These functions are used to add new collation sequences to the
** [database connection] specified as the first argument.
**
** ^The name of the new collation sequence is specified as a UTF-8 string
** for sqlite3_create_collation() and sqlite3_create_collation_v2()
** and a UTF-16 string for sqlite3_create_collation16(). ^In all cases
** the name is passed as the second function argument.
**
** ^The third argument may be one of the constants [SQLITE_UTF8],
** [SQLITE_UTF16LE], or [SQLITE_UTF16BE], indicating that the user-supplied
** routine expects to be passed pointers to strings encoded using UTF-8,
** UTF-16 little-endian, or UTF-16 big-endian, respectively. ^The
** third argument might also be [SQLITE_UTF16] to indicate that the routine
** expects pointers to be UTF-16 strings in the native byte order, or the
** argument can be [SQLITE_UTF16_ALIGNED] if the
** the routine expects pointers to 16-bit word aligned strings
** of UTF-16 in the native byte order.
**
** A pointer to the user supplied routine must be passed as the fifth
** argument.  ^If it is NULL, this is the same as deleting the collation
** sequence (so that SQLite cannot call it anymore).
** ^Each time the application supplied function is invoked, it is passed
** as its first parameter a copy of the void* passed as the fourth argument
** to sqlite3_create_collation() or sqlite3_create_collation16().
**
** ^The remaining arguments to the application-supplied routine are two strings,
** each represented by a (length, data) pair and encoded in the encoding
** that was passed as the third argument when the collation sequence was
** registered.  The application defined collation routine should
** return negative, zero or positive if the first string is less than,
** equal to, or greater than the second string. i.e. (STRING1 - STRING2).
**
** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
** except that it takes an extra argument which is a destructor for
** the collation.  ^The destructor is called when the collation is
** destroyed and is passed a copy of the fourth parameter void* pointer
** of the sqlite3_create_collation_v2().
** ^Collations are destroyed when they are overridden by later calls to the
** collation creation functions or when the [database connection] is closed
** using [sqlite3_close()].
**
** See also:  [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].




*/
int sqlite3_create_collation(
  sqlite3*, 
  const char *zName, 
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
................................................................................
  const void *zName,
  int eTextRep, 
  void*,
  int(*xCompare)(void*,int,const void*,int,const void*)
);

/*
** CAPI3REF: Collation Needed Callbacks
**
** ^To avoid having to register all collation sequences before a database
** can be used, a single callback function may be registered with the
** [database connection] to be invoked whenever an undefined collation
** sequence is required.
**
** ^If the function is registered using the sqlite3_collation_needed() API,
** then it is passed the names of undefined collation sequences as strings
** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
** the names are passed as UTF-16 in machine native byte order.
** ^A call to either function replaces the existing collation-needed callback.
**
** ^(When the callback is invoked, the first argument passed is a copy
** of the second argument to sqlite3_collation_needed() or
** sqlite3_collation_needed16().  The second argument is the database
** connection.  The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
** sequence function required.  The fourth parameter is the name of the
** required collation sequence.)^
**
** The callback function should register the desired collation using
** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
** [sqlite3_create_collation_v2()].



*/
int sqlite3_collation_needed(
  sqlite3*, 
  void*, 
  void(*)(void*,sqlite3*,int eTextRep,const char*)
);
int sqlite3_collation_needed16(
................................................................................
*/
int sqlite3_rekey(
  sqlite3 *db,                   /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** CAPI3REF: Suspend Execution For A Short Time
**
** ^The sqlite3_sleep() function causes the current thread to suspend execution
** for at least a number of milliseconds specified in its parameter.
**
** ^If the operating system does not support sleep requests with
** millisecond time resolution, then the time will be rounded up to
** the nearest second. ^The number of milliseconds of sleep actually
** requested from the operating system is returned.
**
** ^SQLite implements this interface by calling the xSleep()
** method of the default [sqlite3_vfs] object.


*/
int sqlite3_sleep(int);

/*
** CAPI3REF: Name Of The Folder Holding Temporary Files
**
** ^(If this global variable is made to point to a string which is
** the name of a folder (a.k.a. directory), then all temporary files
** created by SQLite when using a built-in [sqlite3_vfs | VFS]
** will be placed in that directory.)^  ^If this variable
** is a NULL pointer, then SQLite performs a search for an appropriate
** temporary file directory.
**
** It is not safe to read or modify this variable in more than one
** thread at a time.  It is not safe to read or modify this variable
** if a [database connection] is being used at the same time in a separate
** thread.
** It is intended that this variable be set once
** as part of process initialization and before any SQLite interface
** routines have been called and that this variable remain unchanged
** thereafter.
**
** ^The [temp_store_directory pragma] may modify this variable and cause
** it to point to memory obtained from [sqlite3_malloc].  ^Furthermore,
** the [temp_store_directory pragma] always assumes that any string
** that this variable points to is held in memory obtained from 
** [sqlite3_malloc] and the pragma may attempt to free that memory
** using [sqlite3_free].
** Hence, if this variable is modified directly, either it should be
** made NULL or made to point to memory obtained from [sqlite3_malloc]
** or else the use of the [temp_store_directory pragma] should be avoided.
*/
SQLITE_EXTERN char *sqlite3_temp_directory;

/*
** CAPI3REF: Test For Auto-Commit Mode
** KEYWORDS: {autocommit mode}
**
** ^The sqlite3_get_autocommit() interface returns non-zero or
** zero if the given database connection is or is not in autocommit mode,
** respectively.  ^Autocommit mode is on by default.
** ^Autocommit mode is disabled by a [BEGIN] statement.
** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
**
** If certain kinds of errors occur on a statement within a multi-statement
** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
** transaction might be rolled back automatically.  The only way to
** find out whether SQLite automatically rolled back the transaction after
** an error is to use this function.
**
** If another thread changes the autocommit status of the database
** connection while this routine is running, then the return value
** is undefined.


*/
int sqlite3_get_autocommit(sqlite3*);

/*
** CAPI3REF: Find The Database Handle Of A Prepared Statement
**
** ^The sqlite3_db_handle interface returns the [database connection] handle
** to which a [prepared statement] belongs.  ^The [database connection]
** returned by sqlite3_db_handle is the same [database connection]
** that was the first argument
** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
** create the statement in the first place.


*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

/*
** CAPI3REF: Find the next prepared statement
**
** ^This interface returns a pointer to the next [prepared statement] after
** pStmt associated with the [database connection] pDb.  ^If pStmt is NULL
** then this interface returns a pointer to the first prepared statement
** associated with the database connection pDb.  ^If no prepared statement
** satisfies the conditions of this routine, it returns NULL.
**
** The [database connection] pointer D in a call to
** [sqlite3_next_stmt(D,S)] must refer to an open database
** connection and in particular must not be a NULL pointer.


*/
sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);

/*
** CAPI3REF: Commit And Rollback Notification Callbacks
**
** ^The sqlite3_commit_hook() interface registers a callback
** function to be invoked whenever a transaction is [COMMIT | committed].
** ^Any callback set by a previous call to sqlite3_commit_hook()
** for the same database connection is overridden.
** ^The sqlite3_rollback_hook() interface registers a callback
** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
** ^Any callback set by a previous call to sqlite3_rollback_hook()
** for the same database connection is overridden.
** ^The pArg argument is passed through to the callback.
** ^If the callback on a commit hook function returns non-zero,
** then the commit is converted into a rollback.
**
** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
** return the P argument from the previous call of the same function
** on the same [database connection] D, or NULL for
** the first call for each function on D.
**
** The callback implementation must not do anything that will modify
** the database connection that invoked the callback.  Any actions
** to modify the database connection must be deferred until after the
** completion of the [sqlite3_step()] call that triggered the commit
** or rollback hook in the first place.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** ^Registering a NULL function disables the callback.
**
** ^When the commit hook callback routine returns zero, the [COMMIT]
** operation is allowed to continue normally.  ^If the commit hook
** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
** ^The rollback hook is invoked on a rollback that results from a commit
** hook returning non-zero, just as it would be with any other rollback.
**
** ^For the purposes of this API, a transaction is said to have been
** rolled back if an explicit "ROLLBACK" statement is executed, or
** an error or constraint causes an implicit rollback to occur.
** ^The rollback callback is not invoked if a transaction is
** automatically rolled back because the database connection is closed.
** ^The rollback callback is not invoked if a transaction is
** rolled back because a commit callback returned non-zero.

**
** See also the [sqlite3_update_hook()] interface.




*/
void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);

/*
** CAPI3REF: Data Change Notification Callbacks
**
** ^The sqlite3_update_hook() interface registers a callback function
** with the [database connection] identified by the first argument
** to be invoked whenever a row is updated, inserted or deleted.
** ^Any callback set by a previous call to this function
** for the same database connection is overridden.
**
** ^The second argument is a pointer to the function to invoke when a
** row is updated, inserted or deleted.
** ^The first argument to the callback is a copy of the third argument
** to sqlite3_update_hook().
** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
** or [SQLITE_UPDATE], depending on the operation that caused the callback
** to be invoked.
** ^The third and fourth arguments to the callback contain pointers to the
** database and table name containing the affected row.
** ^The final callback parameter is the [rowid] of the row.
** ^In the case of an update, this is the [rowid] after the update takes place.
**
** ^(The update hook is not invoked when internal system tables are
** modified (i.e. sqlite_master and sqlite_sequence).)^
**
** ^In the current implementation, the update hook
** is not invoked when duplication rows are deleted because of an
** [ON CONFLICT | ON CONFLICT REPLACE] clause.  ^Nor is the update hook
** invoked when rows are deleted using the [truncate optimization].
** The exceptions defined in this paragraph might change in a future
** release of SQLite.
**
** The update hook implementation must not do anything that will modify
** the database connection that invoked the update hook.  Any actions
** to modify the database connection must be deferred until after the
** completion of the [sqlite3_step()] call that triggered the update hook.
** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
** database connections for the meaning of "modify" in this paragraph.
**
** ^The sqlite3_update_hook(D,C,P) function
** returns the P argument from the previous call
** on the same [database connection] D, or NULL for
** the first call on D.
**
** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
** interfaces.



*/
void *sqlite3_update_hook(
  sqlite3*, 
  void(*)(void *,int ,char const *,char const *,sqlite3_int64),
  void*
);

/*
** CAPI3REF: Enable Or Disable Shared Pager Cache
** KEYWORDS: {shared cache}
**
** ^(This routine enables or disables the sharing of the database cache
** and schema data structures between [database connection | connections]
** to the same database. Sharing is enabled if the argument is true
** and disabled if the argument is false.)^
**
** ^Cache sharing is enabled and disabled for an entire process.
** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
** sharing was enabled or disabled for each thread separately.
**
** ^(The cache sharing mode set by this interface effects all subsequent
** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
** Existing database connections continue use the sharing mode
** that was in effect at the time they were opened.)^
**




** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
** successfully.  An [error code] is returned otherwise.)^
**
** ^Shared cache is disabled by default. But this might change in
** future releases of SQLite.  Applications that care about shared
** cache setting should set it explicitly.
**
** See Also:  [SQLite Shared-Cache Mode]


*/
int sqlite3_enable_shared_cache(int);

/*
** CAPI3REF: Attempt To Free Heap Memory
**
** ^The sqlite3_release_memory() interface attempts to free N bytes
** of heap memory by deallocating non-essential memory allocations
** held by the database library.   Memory used to cache database
** pages to improve performance is an example of non-essential memory.
** ^sqlite3_release_memory() returns the number of bytes actually freed,
** which might be more or less than the amount requested.


*/
int sqlite3_release_memory(int);

/*
** CAPI3REF: Impose A Limit On Heap Size
**
** ^The sqlite3_soft_heap_limit() interface places a "soft" limit
** on the amount of heap memory that may be allocated by SQLite.
** ^If an internal allocation is requested that would exceed the
** soft heap limit, [sqlite3_release_memory()] is invoked one or
** more times to free up some space before the allocation is performed.
**
** ^The limit is called "soft" because if [sqlite3_release_memory()]
** cannot free sufficient memory to prevent the limit from being exceeded,
** the memory is allocated anyway and the current operation proceeds.
**
** ^A negative or zero value for N means that there is no soft heap limit and
** [sqlite3_release_memory()] will only be called when memory is exhausted.
** ^The default value for the soft heap limit is zero.
**
** ^(SQLite makes a best effort to honor the soft heap limit.
** But if the soft heap limit cannot be honored, execution will
** continue without error or notification.)^  This is why the limit is
** called a "soft" limit.  It is advisory only.
**
** Prior to SQLite version 3.5.0, this routine only constrained the memory
** allocated by a single thread - the same thread in which this routine
** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
** applied to all threads. The value specified for the soft heap limit
** is an upper bound on the total memory allocation for all threads. In
** version 3.5.0 there is no mechanism for limiting the heap usage for
** individual threads.



*/
void sqlite3_soft_heap_limit(int);

/*
** CAPI3REF: Extract Metadata About A Column Of A Table
**
** ^This routine returns metadata about a specific column of a specific
** database table accessible using the [database connection] handle
** passed as the first function argument.
**
** ^The column is identified by the second, third and fourth parameters to
** this function. ^The second parameter is either the name of the database
** (i.e. "main", "temp", or an attached database) containing the specified
** table or NULL. ^If it is NULL, then all attached databases are searched
** for the table using the same algorithm used by the database engine to
** resolve unqualified table references.
**
** ^The third and fourth parameters to this function are the table and column
** name of the desired column, respectively. Neither of these parameters
** may be NULL.
**
** ^Metadata is returned by writing to the memory locations passed as the 5th
** and subsequent parameters to this function. ^Any of these arguments may be
** NULL, in which case the corresponding element of metadata is omitted.
**
** ^(<blockquote>
** <table border="1">
** <tr><th> Parameter <th> Output<br>Type <th>  Description
**
** <tr><td> 5th <td> const char* <td> Data type
** <tr><td> 6th <td> const char* <td> Name of default collation sequence
** <tr><td> 7th <td> int         <td> True if column has a NOT NULL constraint
** <tr><td> 8th <td> int         <td> True if column is part of the PRIMARY KEY
** <tr><td> 9th <td> int         <td> True if column is [AUTOINCREMENT]
** </table>
** </blockquote>)^
**
** ^The memory pointed to by the character pointers returned for the
** declaration type and collation sequence is valid only until the next
** call to any SQLite API function.
**
** ^If the specified table is actually a view, an [error code] is returned.
**
** ^If the specified column is "rowid", "oid" or "_rowid_" and an
** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
** parameters are set for the explicitly declared column. ^(If there is no
** explicitly declared [INTEGER PRIMARY KEY] column, then the output
** parameters are set as follows:
**
** <pre>
**     data type: "INTEGER"
**     collation sequence: "BINARY"
**     not null: 0
**     primary key: 1
**     auto increment: 0
** </pre>)^
**
** ^(This function may load one or more schemas from database files. If an
** error occurs during this process, or if the requested table or column
** cannot be found, an [error code] is returned and an error message left
** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^
**
** ^This API is only available if the library was compiled with the
** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined.
*/
int sqlite3_table_column_metadata(
  sqlite3 *db,                /* Connection handle */
  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
................................................................................
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
);

/*
** CAPI3REF: Load An Extension
**
** ^This interface loads an SQLite extension library from the named file.
**
** ^The sqlite3_load_extension() interface attempts to load an
** SQLite extension library contained in the file zFile.
**
** ^The entry point is zProc.

** ^zProc may be 0, in which case the name of the entry point
** defaults to "sqlite3_extension_init".

** ^The sqlite3_load_extension() interface returns
** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.

** ^If an error occurs and pzErrMsg is not 0, then the
** [sqlite3_load_extension()] interface shall attempt to
** fill *pzErrMsg with error message text stored in memory
** obtained from [sqlite3_malloc()]. The calling function
** should free this memory by calling [sqlite3_free()].
**
** ^Extension loading must be enabled using
** [sqlite3_enable_load_extension()] prior to calling this API,
** otherwise an error will be returned.
**
** See also the [load_extension() SQL function].
*/
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
);

/*
** CAPI3REF: Enable Or Disable Extension Loading
**
** ^So as not to open security holes in older applications that are
** unprepared to deal with extension loading, and as a means of disabling
** extension loading while evaluating user-entered SQL, the following API
** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
**
** ^Extension loading is off by default. See ticket #1863.

** ^Call the sqlite3_enable_load_extension() routine with onoff==1
** to turn extension loading on and call it with onoff==0 to turn
** it back off again.


*/
int sqlite3_enable_load_extension(sqlite3 *db, int onoff);

/*
** CAPI3REF: Automatically Load An Extensions
**
** ^This API can be invoked at program startup in order to register
** one or more statically linked extensions that will be available
** to all new [database connections].
**
** ^(This routine stores a pointer to the extension entry point
** in an array that is obtained from [sqlite3_malloc()].  That memory

** is deallocated by [sqlite3_reset_auto_extension()].)^
**
** ^This function registers an extension entry point that is
** automatically invoked whenever a new [database connection]
** is opened using [sqlite3_open()], [sqlite3_open16()],
** or [sqlite3_open_v2()].

** ^Duplicate extensions are detected so calling this routine
** multiple times with the same extension is harmless.




** ^Automatic extensions apply across all threads.
*/
int sqlite3_auto_extension(void (*xEntryPoint)(void));

/*
** CAPI3REF: Reset Automatic Extension Loading
**
** ^(This function disables all previously registered automatic
** extensions. It undoes the effect of all prior
** [sqlite3_auto_extension()] calls.)^
**



** ^This function disables automatic extensions in all threads.
*/
void sqlite3_reset_auto_extension(void);

/*
****** EXPERIMENTAL - subject to change without notice **************
**
** The interface to the virtual-table mechanism is currently considered
................................................................................
*/
typedef struct sqlite3_vtab sqlite3_vtab;
typedef struct sqlite3_index_info sqlite3_index_info;
typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
typedef struct sqlite3_module sqlite3_module;

/*
** CAPI3REF: Virtual Table Object
** KEYWORDS: sqlite3_module {virtual table module}
** EXPERIMENTAL
**
** This structure, sometimes called a a "virtual table module", 
** defines the implementation of a [virtual tables].  
** This structure consists mostly of methods for the module.
**
** ^A virtual table module is created by filling in a persistent
** instance of this structure and passing a pointer to that instance
** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
** ^The registration remains valid until it is replaced by a different
** module or until the [database connection] closes.  The content
** of this structure must not change while it is registered with
** any database connection.
*/
struct sqlite3_module {
  int iVersion;
  int (*xCreate)(sqlite3*, void *pAux,
................................................................................
  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
                       void **ppArg);
  int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
};

/*
** CAPI3REF: Virtual Table Indexing Information
** KEYWORDS: sqlite3_index_info
** EXPERIMENTAL
**
** The sqlite3_index_info structure and its substructures is used to
** pass information into and receive the reply from the [xBestIndex]
** method of a [virtual table module].  The fields under **Inputs** are the
** inputs to xBestIndex and are read-only.  xBestIndex inserts its
** results into the **Outputs** fields.
**
** ^(The aConstraint[] array records WHERE clause constraints of the form:
**
** <pre>column OP expr</pre>
**
** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^  ^(The particular operator is
** stored in aConstraint[].op.)^  ^(The index of the column is stored in
** aConstraint[].iColumn.)^  ^(aConstraint[].usable is TRUE if the
** expr on the right-hand side can be evaluated (and thus the constraint
** is usable) and false if it cannot.)^
**
** ^The optimizer automatically inverts terms of the form "expr OP column"
** and makes other simplifications to the WHERE clause in an attempt to
** get as many WHERE clause terms into the form shown above as possible.
** ^The aConstraint[] array only reports WHERE clause terms that are
** relevant to the particular virtual table being queried.
**
** ^Information about the ORDER BY clause is stored in aOrderBy[].
** ^Each term of aOrderBy records a column of the ORDER BY clause.
**
** The [xBestIndex] method must fill aConstraintUsage[] with information
** about what parameters to pass to xFilter.  ^If argvIndex>0 then
** the right-hand side of the corresponding aConstraint[] is evaluated
** and becomes the argvIndex-th entry in argv.  ^(If aConstraintUsage[].omit
** is true, then the constraint is assumed to be fully handled by the
** virtual table and is not checked again by SQLite.)^
**
** ^The idxNum and idxPtr values are recorded and passed into the
** [xFilter] method.
** ^[sqlite3_free()] is used to free idxPtr if and only if
** needToFreeIdxPtr is true.
**
** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
** the correct order to satisfy the ORDER BY clause so that no separate
** sorting step is required.
**
** ^The estimatedCost value is an estimate of the cost of doing the
** particular lookup.  A full scan of a table with N entries should have
** a cost of N.  A binary search of a table of N entries should have a
** cost of approximately log(N).
*/
struct sqlite3_index_info {
  /* Inputs */
  int nConstraint;           /* Number of entries in aConstraint */
................................................................................
#define SQLITE_INDEX_CONSTRAINT_GT    4
#define SQLITE_INDEX_CONSTRAINT_LE    8
#define SQLITE_INDEX_CONSTRAINT_LT    16
#define SQLITE_INDEX_CONSTRAINT_GE    32
#define SQLITE_INDEX_CONSTRAINT_MATCH 64

/*
** CAPI3REF: Register A Virtual Table Implementation
** EXPERIMENTAL
**
** ^These routines are used to register a new [virtual table module] name.
** ^Module names must be registered before
** creating a new [virtual table] using the module and before using a
** preexisting [virtual table] for the module.
**
** ^The module name is registered on the [database connection] specified
** by the first parameter.  ^The name of the module is given by the 
** second parameter.  ^The third parameter is a pointer to
** the implementation of the [virtual table module].   ^The fourth
** parameter is an arbitrary client data pointer that is passed through
** into the [xCreate] and [xConnect] methods of the virtual table module
** when a new virtual table is be being created or reinitialized.
**

** ^The sqlite3_create_module_v2() interface has a fifth parameter which
** is a pointer to a destructor for the pClientData.  ^SQLite will
** invoke the destructor function (if it is not NULL) when SQLite
** no longer needs the pClientData pointer.  ^The sqlite3_create_module()
** interface is equivalent to sqlite3_create_module_v2() with a NULL
** destructor.
*/
SQLITE_EXPERIMENTAL int sqlite3_create_module(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *p,   /* Methods for the module */
  void *pClientData          /* Client data for xCreate/xConnect */
);











SQLITE_EXPERIMENTAL int sqlite3_create_module_v2(
  sqlite3 *db,               /* SQLite connection to register module with */
  const char *zName,         /* Name of the module */
  const sqlite3_module *p,   /* Methods for the module */
  void *pClientData,         /* Client data for xCreate/xConnect */
  void(*xDestroy)(void*)     /* Module destructor function */
);

/*
** CAPI3REF: Virtual Table Instance Object
** KEYWORDS: sqlite3_vtab
** EXPERIMENTAL
**
** Every [virtual table module] implementation uses a subclass
** of this object to describe a particular instance
** of the [virtual table].  Each subclass will
** be tailored to the specific needs of the module implementation.
** The purpose of this superclass is to define certain fields that are
** common to all module implementations.
**
** ^Virtual tables methods can set an error message by assigning a
** string obtained from [sqlite3_mprintf()] to zErrMsg.  The method should
** take care that any prior string is freed by a call to [sqlite3_free()]
** prior to assigning a new string to zErrMsg.  ^After the error message
** is delivered up to the client application, the string will be automatically
** freed by sqlite3_free() and the zErrMsg field will be zeroed.
*/
struct sqlite3_vtab {
  const sqlite3_module *pModule;  /* The module for this virtual table */
  int nRef;                       /* NO LONGER USED */
  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Virtual Table Cursor Object
** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
** EXPERIMENTAL
**
** Every [virtual table module] implementation uses a subclass of the
** following structure to describe cursors that point into the
** [virtual table] and are used
** to loop through the virtual table.  Cursors are created using the
** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
** by the [sqlite3_module.xClose | xClose] method.  Cursors are used
** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
** of the module.  Each module implementation will define
** the content of a cursor structure to suit its own needs.
**
** This superclass exists in order to define fields of the cursor that
** are common to all implementations.
*/
struct sqlite3_vtab_cursor {
  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
  /* Virtual table implementations will typically add additional fields */
};

/*
** CAPI3REF: Declare The Schema Of A Virtual Table
** EXPERIMENTAL
**
** ^The [xCreate] and [xConnect] methods of a
** [virtual table module] call this interface
** to declare the format (the names and datatypes of the columns) of
** the virtual tables they implement.
*/
SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zSQL);

/*
** CAPI3REF: Overload A Function For A Virtual Table
** EXPERIMENTAL
**
** ^(Virtual tables can provide alternative implementations of functions
** using the [xFindFunction] method of the [virtual table module].  
** But global versions of those functions
** must exist in order to be overloaded.)^
**
** ^(This API makes sure a global version of a function with a particular
** name and number of parameters exists.  If no such function exists
** before this API is called, a new function is created.)^  ^The implementation
** of the new function always causes an exception to be thrown.  So
** the new function is not good for anything by itself.  Its only
** purpose is to be a placeholder function that can be overloaded
** by a [virtual table].
*/
SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);

................................................................................
** When the virtual-table mechanism stabilizes, we will declare the
** interface fixed, support it indefinitely, and remove this comment.
**
****** EXPERIMENTAL - subject to change without notice **************
*/

/*
** CAPI3REF: A Handle To An Open BLOB
** KEYWORDS: {BLOB handle} {BLOB handles}
**
** An instance of this object represents an open BLOB on which
** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
** ^Objects of this type are created by [sqlite3_blob_open()]
** and destroyed by [sqlite3_blob_close()].
** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
** can be used to read or write small subsections of the BLOB.
** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
*/
typedef struct sqlite3_blob sqlite3_blob;

/*
** CAPI3REF: Open A BLOB For Incremental I/O
**
** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
** in row iRow, column zColumn, table zTable in database zDb;
** in other words, the same BLOB that would be selected by:
**
** <pre>
**     SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
** </pre>)^
**
** ^If the flags parameter is non-zero, then the BLOB is opened for read
** and write access. ^If it is zero, the BLOB is opened for read access.
** ^It is not possible to open a column that is part of an index or primary 
** key for writing. ^If [foreign key constraints] are enabled, it is 
** not possible to open a column that is part of a [child key] for writing.
**
** ^Note that the database name is not the filename that contains
** the database but rather the symbolic name of the database that
** appears after the AS keyword when the database is connected using [ATTACH].
** ^For the main database file, the database name is "main".
** ^For TEMP tables, the database name is "temp".
**
** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written
** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set
** to be a null pointer.)^
** ^This function sets the [database connection] error code and message
** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related
** functions. ^Note that the *ppBlob variable is always initialized in a
** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob
** regardless of the success or failure of this routine.
**
** ^(If the row that a BLOB handle points to is modified by an
** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
** then the BLOB handle is marked as "expired".
** This is true if any column of the row is changed, even a column
** other than the one the BLOB handle is open on.)^
** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
** a expired BLOB handle fail with an return code of [SQLITE_ABORT].
** ^(Changes written into a BLOB prior to the BLOB expiring are not
** rolled back by the expiration of the BLOB.  Such changes will eventually
** commit if the transaction continues to completion.)^
**
** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
** the opened blob.  ^The size of a blob may not be changed by this
** interface.  Use the [UPDATE] SQL command to change the size of a
** blob.
**
** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
** and the built-in [zeroblob] SQL function can be used, if desired,
** to create an empty, zero-filled blob in which to read or write using
** this interface.
**
** To avoid a resource leak, every open [BLOB handle] should eventually
** be released by a call to [sqlite3_blob_close()].



*/
int sqlite3_blob_open(
  sqlite3*,
  const char *zDb,
  const char *zTable,
  const char *zColumn,
  sqlite3_int64 iRow,
  int flags,
  sqlite3_blob **ppBlob
);

/*
** CAPI3REF: Close A BLOB Handle
**
** ^Closes an open [BLOB handle].
**
** ^Closing a BLOB shall cause the current transaction to commit
** if there are no other BLOBs, no pending prepared statements, and the
** database connection is in [autocommit mode].
** ^If any writes were made to the BLOB, they might be held in cache
** until the close operation if they will fit.
**
** ^(Closing the BLOB often forces the changes
** out to disk and so if any I/O errors occur, they will likely occur
** at the time when the BLOB is closed.  Any errors that occur during
** closing are reported as a non-zero return value.)^
**
** ^(The BLOB is closed unconditionally.  Even if this routine returns
** an error code, the BLOB is still closed.)^
**
** ^Calling this routine with a null pointer (such as would be returned
** by a failed call to [sqlite3_blob_open()]) is a harmless no-op.



*/
int sqlite3_blob_close(sqlite3_blob *);

/*
** CAPI3REF: Return The Size Of An Open BLOB
**
** ^Returns the size in bytes of the BLOB accessible via the 
** successfully opened [BLOB handle] in its only argument.  ^The
** incremental blob I/O routines can only read or overwriting existing
** blob content; they cannot change the size of a blob.
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.



*/
int sqlite3_blob_bytes(sqlite3_blob *);

/*
** CAPI3REF: Read Data From A BLOB Incrementally
**
** ^(This function is used to read data from an open [BLOB handle] into a
** caller-supplied buffer. N bytes of data are copied into buffer Z
** from the open BLOB, starting at offset iOffset.)^
**
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is read.  ^If N or iOffset is
** less than zero, [SQLITE_ERROR] is returned and no data is read.
** ^The size of the blob (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.
**
** ^An attempt to read from an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].
**
** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
** Otherwise, an [error code] or an [extended error code] is returned.)^
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_write()].



*/
int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);

/*
** CAPI3REF: Write Data Into A BLOB Incrementally
**
** ^This function is used to write data into an open [BLOB handle] from a
** caller-supplied buffer. ^N bytes of data are copied from the buffer Z
** into the open BLOB, starting at offset iOffset.
**
** ^If the [BLOB handle] passed as the first argument was not opened for
** writing (the flags parameter to [sqlite3_blob_open()] was zero),
** this function returns [SQLITE_READONLY].
**
** ^This function may only modify the contents of the BLOB; it is
** not possible to increase the size of a BLOB using this API.
** ^If offset iOffset is less than N bytes from the end of the BLOB,
** [SQLITE_ERROR] is returned and no data is written.  ^If N is
** less than zero [SQLITE_ERROR] is returned and no data is written.
** The size of the BLOB (and hence the maximum value of N+iOffset)
** can be determined using the [sqlite3_blob_bytes()] interface.
**
** ^An attempt to write to an expired [BLOB handle] fails with an
** error code of [SQLITE_ABORT].  ^Writes to the BLOB that occurred
** before the [BLOB handle] expired are not rolled back by the
** expiration of the handle, though of course those changes might
** have been overwritten by the statement that expired the BLOB handle
** or by other independent statements.
**
** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
** Otherwise, an  [error code] or an [extended error code] is returned.)^
**
** This routine only works on a [BLOB handle] which has been created
** by a prior successful call to [sqlite3_blob_open()] and which has not
** been closed by [sqlite3_blob_close()].  Passing any other pointer in
** to this routine results in undefined and probably undesirable behavior.
**
** See also: [sqlite3_blob_read()].




*/
int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);

/*
** CAPI3REF: Virtual File System Objects
**
** A virtual filesystem (VFS) is an [sqlite3_vfs] object
** that SQLite uses to interact
** with the underlying operating system.  Most SQLite builds come with a
** single default VFS that is appropriate for the host computer.
** New VFSes can be registered and existing VFSes can be unregistered.
** The following interfaces are provided.
**
** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
** ^Names are case sensitive.
** ^Names are zero-terminated UTF-8 strings.
** ^If there is no match, a NULL pointer is returned.
** ^If zVfsName is NULL then the default VFS is returned.
**
** ^New VFSes are registered with sqlite3_vfs_register().
** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
** ^The same VFS can be registered multiple times without injury.
** ^To make an existing VFS into the default VFS, register it again
** with the makeDflt flag set.  If two different VFSes with the
** same name are registered, the behavior is undefined.  If a
** VFS is registered with a name that is NULL or an empty string,
** then the behavior is undefined.
**
** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
** ^(If the default VFS is unregistered, another VFS is chosen as
** the default.  The choice for the new VFS is arbitrary.)^



*/
sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
int sqlite3_vfs_unregister(sqlite3_vfs*);

/*
** CAPI3REF: Mutexes
**
** The SQLite core uses these routines for thread
** synchronization. Though they are intended for internal
** use by SQLite, code that links against SQLite is
** permitted to use any of these routines.
**
** The SQLite source code contains multiple implementations
** of these mutex routines.  An appropriate implementation
** is selected automatically at compile-time.  ^(The following
** implementations are available in the SQLite core:
**
** <ul>
** <li>   SQLITE_MUTEX_OS2
** <li>   SQLITE_MUTEX_PTHREAD
** <li>   SQLITE_MUTEX_W32
** <li>   SQLITE_MUTEX_NOOP
** </ul>)^
**
** ^The SQLITE_MUTEX_NOOP implementation is a set of routines
** that does no real locking and is appropriate for use in
** a single-threaded application.  ^The SQLITE_MUTEX_OS2,
** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
** are appropriate for use on OS/2, Unix, and Windows.
**
** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
** implementation is included with the library. In this case the
** application must supply a custom mutex implementation using the
** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
** before calling sqlite3_initialize() or any other public sqlite3_
** function that calls sqlite3_initialize().)^
**
** ^The sqlite3_mutex_alloc() routine allocates a new
** mutex and returns a pointer to it. ^If it returns NULL
** that means that a mutex could not be allocated.  ^SQLite
** will unwind its stack and return an error.  ^(The argument
** to sqlite3_mutex_alloc() is one of these integer constants:
**
** <ul>
** <li>  SQLITE_MUTEX_FAST
** <li>  SQLITE_MUTEX_RECURSIVE
** <li>  SQLITE_MUTEX_STATIC_MASTER
** <li>  SQLITE_MUTEX_STATIC_MEM
** <li>  SQLITE_MUTEX_STATIC_MEM2
** <li>  SQLITE_MUTEX_STATIC_PRNG
** <li>  SQLITE_MUTEX_STATIC_LRU
** <li>  SQLITE_MUTEX_STATIC_LRU2
** </ul>)^
**
** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
** cause sqlite3_mutex_alloc() to create
** a new mutex.  ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
** The mutex implementation does not need to make a distinction
** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
** not want to.  ^SQLite will only request a recursive mutex in
** cases where it really needs one.  ^If a faster non-recursive mutex
** implementation is available on the host platform, the mutex subsystem
** might return such a mutex in response to SQLITE_MUTEX_FAST.
**
** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
** a pointer to a static preexisting mutex.  ^Six static mutexes are
** used by the current version of SQLite.  Future versions of SQLite
** may add additional static mutexes.  Static mutexes are for internal
** use by SQLite only.  Applications that use SQLite mutexes should
** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
** SQLITE_MUTEX_RECURSIVE.
**
** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
** returns a different mutex on every call.  ^But for the static
** mutex types, the same mutex is returned on every call that has
** the same type number.
**
** ^The sqlite3_mutex_free() routine deallocates a previously
** allocated dynamic mutex.  ^SQLite is careful to deallocate every
** dynamic mutex that it allocates.  The dynamic mutexes must not be in
** use when they are deallocated.  Attempting to deallocate a static
** mutex results in undefined behavior.  ^SQLite never deallocates
** a static mutex.
**
** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
** to enter a mutex.  ^If another thread is already within the mutex,
** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
** SQLITE_BUSY.  ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
** upon successful entry.  ^(Mutexes created using
** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
** In such cases the,
** mutex must be exited an equal number of times before another thread
** can enter.)^  ^(If the same thread tries to enter any other
** kind of mutex more than once, the behavior is undefined.
** SQLite will never exhibit
** such behavior in its own use of mutexes.)^
**
** ^(Some systems (for example, Windows 95) do not support the operation
** implemented by sqlite3_mutex_try().  On those systems, sqlite3_mutex_try()
** will always return SQLITE_BUSY.  The SQLite core only ever uses
** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^
**
** ^The sqlite3_mutex_leave() routine exits a mutex that was
** previously entered by the same thread.   ^(The behavior
** is undefined if the mutex is not currently entered by the
** calling thread or is not currently allocated.  SQLite will
** never do either.)^
**
** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
** sqlite3_mutex_leave() is a NULL pointer, then all three routines
** behave as no-ops.
**
** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
*/
sqlite3_mutex *sqlite3_mutex_alloc(int);
void sqlite3_mutex_free(sqlite3_mutex*);
void sqlite3_mutex_enter(sqlite3_mutex*);
int sqlite3_mutex_try(sqlite3_mutex*);
void sqlite3_mutex_leave(sqlite3_mutex*);

/*
** CAPI3REF: Mutex Methods Object
** EXPERIMENTAL
**
** An instance of this structure defines the low-level routines
** used to allocate and use mutexes.
**
** Usually, the default mutex implementations provided by SQLite are
** sufficient, however the user has the option of substituting a custom
................................................................................
** does not provide a suitable implementation. In this case, the user
** creates and populates an instance of this structure to pass
** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
** Additionally, an instance of this structure can be used as an
** output variable when querying the system for the current mutex
** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
**
** ^The xMutexInit method defined by this structure is invoked as
** part of system initialization by the sqlite3_initialize() function.
** ^The xMutexInit routine is calle by SQLite exactly once for each
** effective call to [sqlite3_initialize()].
**
** ^The xMutexEnd method defined by this structure is invoked as
** part of system shutdown by the sqlite3_shutdown() function. The
** implementation of this method is expected to release all outstanding
** resources obtained by the mutex methods implementation, especially
** those obtained by the xMutexInit method.  ^The xMutexEnd()
** interface is invoked exactly once for each call to [sqlite3_shutdown()].
**
** ^(The remaining seven methods defined by this structure (xMutexAlloc,
** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
** xMutexNotheld) implement the following interfaces (respectively):
**
** <ul>
**   <li>  [sqlite3_mutex_alloc()] </li>
**   <li>  [sqlite3_mutex_free()] </li>
**   <li>  [sqlite3_mutex_enter()] </li>
**   <li>  [sqlite3_mutex_try()] </li>
**   <li>  [sqlite3_mutex_leave()] </li>
**   <li>  [sqlite3_mutex_held()] </li>
**   <li>  [sqlite3_mutex_notheld()] </li>
** </ul>)^
**
** The only difference is that the public sqlite3_XXX functions enumerated
** above silently ignore any invocations that pass a NULL pointer instead
** of a valid mutex handle. The implementations of the methods defined
** by this structure are not required to handle this case, the results
** of passing a NULL pointer instead of a valid mutex handle are undefined
** (i.e. it is acceptable to provide an implementation that segfaults if
** it is passed a NULL pointer).
**
** The xMutexInit() method must be threadsafe.  ^It must be harmless to
** invoke xMutexInit() mutiple times within the same process and without
** intervening calls to xMutexEnd().  Second and subsequent calls to
** xMutexInit() must be no-ops.
**
** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
** and its associates).  ^Similarly, xMutexAlloc() must not use SQLite memory
** allocation for a static mutex.  ^However xMutexAlloc() may use SQLite
** memory allocation for a fast or recursive mutex.
**
** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
** called, but only if the prior call to xMutexInit returned SQLITE_OK.
** If xMutexInit fails in any way, it is expected to clean up after itself
** prior to returning.
*/
typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
struct sqlite3_mutex_methods {
  int (*xMutexInit)(void);
................................................................................
  int (*xMutexTry)(sqlite3_mutex *);
  void (*xMutexLeave)(sqlite3_mutex *);
  int (*xMutexHeld)(sqlite3_mutex *);
  int (*xMutexNotheld)(sqlite3_mutex *);
};

/*
** CAPI3REF: Mutex Verification Routines
**
** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
** are intended for use inside assert() statements.  ^The SQLite core
** never uses these routines except inside an assert() and applications
** are advised to follow the lead of the core.  ^The SQLite core only
** provides implementations for these routines when it is compiled
** with the SQLITE_DEBUG flag.  ^External mutex implementations
** are only required to provide these routines if SQLITE_DEBUG is
** defined and if NDEBUG is not defined.
**
** ^These routines should return true if the mutex in their argument
** is held or not held, respectively, by the calling thread.
**
** ^The implementation is not required to provided versions of these
** routines that actually work. If the implementation does not provide working
** versions of these routines, it should at least provide stubs that always
** return true so that one does not get spurious assertion failures.
**
** ^If the argument to sqlite3_mutex_held() is a NULL pointer then
** the routine should return 1.   This seems counter-intuitive since
** clearly the mutex cannot be held if it does not exist.  But the
** the reason the mutex does not exist is because the build is not
** using mutexes.  And we do not want the assert() containing the
** call to sqlite3_mutex_held() to fail, so a non-zero return is
** the appropriate thing to do.  ^The sqlite3_mutex_notheld()
** interface should also return 1 when given a NULL pointer.
*/
#ifndef NDEBUG
int sqlite3_mutex_held(sqlite3_mutex*);
int sqlite3_mutex_notheld(sqlite3_mutex*);
#endif

/*
** CAPI3REF: Mutex Types
**
** The [sqlite3_mutex_alloc()] interface takes a single argument
** which is one of these integer constants.
**
** The set of static mutexes may change from one SQLite release to the
** next.  Applications that override the built-in mutex logic must be
** prepared to accommodate additional static mutexes.
................................................................................
#define SQLITE_MUTEX_STATIC_MEM2      4  /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN      4  /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
#define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2      7  /* lru page list */

/*
** CAPI3REF: Retrieve the mutex for a database connection
**
** ^This interface returns a pointer the [sqlite3_mutex] object that 
** serializes access to the [database connection] given in the argument
** when the [threading mode] is Serialized.
** ^If the [threading mode] is Single-thread or Multi-thread then this
** routine returns a NULL pointer.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3*);

/*
** CAPI3REF: Low-Level Control Of Database Files
**
** ^The [sqlite3_file_control()] interface makes a direct call to the
** xFileControl method for the [sqlite3_io_methods] object associated
** with a particular database identified by the second argument. ^The
** name of the database "main" for the main database or "temp" for the
** TEMP database, or the name that appears after the AS keyword for
** databases that are added using the [ATTACH] SQL command.
** ^A NULL pointer can be used in place of "main" to refer to the
** main database file.
** ^The third and fourth parameters to this routine
** are passed directly through to the second and third parameters of
** the xFileControl method.  ^The return value of the xFileControl
** method becomes the return value of this routine.
**
** ^If the second parameter (zDbName) does not match the name of any
** open database file, then SQLITE_ERROR is returned.  ^This error
** code is not remembered and will not be recalled by [sqlite3_errcode()]
** or [sqlite3_errmsg()].  The underlying xFileControl method might
** also return SQLITE_ERROR.  There is no way to distinguish between
** an incorrect zDbName and an SQLITE_ERROR return from the underlying
** xFileControl method.
**
** See also: [SQLITE_FCNTL_LOCKSTATE]
*/
int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);

/*
** CAPI3REF: Testing Interface
**
** ^The sqlite3_test_control() interface is used to read out internal
** state of SQLite and to inject faults into SQLite for testing
** purposes.  ^The first parameter is an operation code that determines
** the number, meaning, and operation of all subsequent parameters.
**
** This interface is not for use by applications.  It exists solely
** for verifying the correct operation of the SQLite library.  Depending
** on how the SQLite library is compiled, this interface might not exist.
**
** The details of the operation codes, their meanings, the parameters
................................................................................
** they take, and what they do are all subject to change without notice.
** Unlike most of the SQLite API, this function is not guaranteed to
** operate consistently from one release to the next.
*/
int sqlite3_test_control(int op, ...);

/*
** CAPI3REF: Testing Interface Operation Codes
**
** These constants are the valid operation code parameters used
** as the first argument to [sqlite3_test_control()].
**
** These parameters and their meanings are subject to change
** without notice.  These values are for testing purposes only.
** Applications should not use any of these parameters or the
................................................................................
#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS     10
#define SQLITE_TESTCTRL_PENDING_BYTE            11
#define SQLITE_TESTCTRL_ASSERT                  12
#define SQLITE_TESTCTRL_ALWAYS                  13
#define SQLITE_TESTCTRL_RESERVE                 14

/*
** CAPI3REF: SQLite Runtime Status
** EXPERIMENTAL
**
** ^This interface is used to retrieve runtime status information
** about the preformance of SQLite, and optionally to reset various
** highwater marks.  ^The first argument is an integer code for
** the specific parameter to measure.  ^(Recognized integer codes
** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...].)^
** ^The current value of the parameter is returned into *pCurrent.
** ^The highest recorded value is returned in *pHighwater.  ^If the
** resetFlag is true, then the highest record value is reset after
** *pHighwater is written.  ^(Some parameters do not record the highest
** value.  For those parameters
** nothing is written into *pHighwater and the resetFlag is ignored.)^
** ^(Other parameters record only the highwater mark and not the current
** value.  For these latter parameters nothing is written into *pCurrent.)^
**
** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
** non-zero [error code] on failure.
**
** This routine is threadsafe but is not atomic.  This routine can be
** called while other threads are running the same or different SQLite
** interfaces.  However the values returned in *pCurrent and
** *pHighwater reflect the status of SQLite at different points in time
** and it is possible that another thread might change the parameter
** in between the times when *pCurrent and *pHighwater are written.
................................................................................
**
** See also: [sqlite3_db_status()]
*/
SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);


/*
** CAPI3REF: Status Parameters
** EXPERIMENTAL
**
** These integer constants designate various run-time status parameters
** that can be returned by [sqlite3_status()].
**
** <dl>
** ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
** <dd>This parameter is the current amount of memory checked out
** using [sqlite3_malloc()], either directly or indirectly.  The
** figure includes calls made to [sqlite3_malloc()] by the application
** and internal memory usage by the SQLite library.  Scratch memory
** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
** this parameter.  The amount returned is the sum of the allocation
** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
**
** ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
** internal equivalents).  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>)^
**
** ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
** <dd>This parameter returns the number of pages used out of the
** [pagecache memory allocator] that was configured using 
** [SQLITE_CONFIG_PAGECACHE].  The
** value returned is in pages, not in bytes.</dd>)^
**
** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
** <dd>This parameter returns the number of bytes of page cache
** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE]
** buffer and where forced to overflow to [sqlite3_malloc()].  The
** returned value includes allocations that overflowed because they
** where too large (they were larger than the "sz" parameter to
** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
** no space was left in the page cache.</dd>)^
**
** ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [pagecache memory allocator].  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>)^
**
** ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
** <dd>This parameter returns the number of allocations used out of the
** [scratch memory allocator] configured using
** [SQLITE_CONFIG_SCRATCH].  The value returned is in allocations, not
** in bytes.  Since a single thread may only have one scratch allocation
** outstanding at time, this parameter also reports the number of threads
** using scratch memory at the same time.</dd>)^
**
** ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
** <dd>This parameter returns the number of bytes of scratch memory
** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH]
** buffer and where forced to overflow to [sqlite3_malloc()].  The values
** returned include overflows because the requested allocation was too
** larger (that is, because the requested allocation was larger than the
** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
** slots were available.
** </dd>)^
**
** ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
** <dd>This parameter records the largest memory allocation request
** handed to [scratch memory allocator].  Only the value returned in the
** *pHighwater parameter to [sqlite3_status()] is of interest.  
** The value written into the *pCurrent parameter is undefined.</dd>)^
**
** ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
** <dd>This parameter records the deepest parser stack.  It is only
** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
** </dl>
**
** New status parameters may be added from time to time.
*/
#define SQLITE_STATUS_MEMORY_USED          0
#define SQLITE_STATUS_PAGECACHE_USED       1
#define SQLITE_STATUS_PAGECACHE_OVERFLOW   2
................................................................................
#define SQLITE_STATUS_SCRATCH_OVERFLOW     4
#define SQLITE_STATUS_MALLOC_SIZE          5
#define SQLITE_STATUS_PARSER_STACK         6
#define SQLITE_STATUS_PAGECACHE_SIZE       7
#define SQLITE_STATUS_SCRATCH_SIZE         8

/*
** CAPI3REF: Database Connection Status
** EXPERIMENTAL
**
** ^This interface is used to retrieve runtime status information 
** about a single [database connection].  ^The first argument is the
** database connection object to be interrogated.  ^The second argument
** is the parameter to interrogate.  ^Currently, the only allowed value
** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED].
** Additional options will likely appear in future releases of SQLite.
**
** ^The current value of the requested parameter is written into *pCur
** and the highest instantaneous value is written into *pHiwtr.  ^If
** the resetFlg is true, then the highest instantaneous value is
** reset back down to the current value.
**
** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
*/
SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);

/*
** CAPI3REF: Status Parameters for database connections
** EXPERIMENTAL
**
** These constants are the available integer "verbs" that can be passed as
** the second argument to the [sqlite3_db_status()] interface.
**
** New verbs may be added in future releases of SQLite. Existing verbs
** might be discontinued. Applications should check the return code from
** [sqlite3_db_status()] to make sure that the call worked.
** The [sqlite3_db_status()] interface will return a non-zero error code
** if a discontinued or unsupported verb is invoked.
**
** <dl>
** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
** <dd>This parameter returns the number of lookaside memory slots currently
** checked out.</dd>)^
** </dl>
*/
#define SQLITE_DBSTATUS_LOOKASIDE_USED     0


/*
** CAPI3REF: Prepared Statement Status
** EXPERIMENTAL
**
** ^(Each prepared statement maintains various
** [SQLITE_STMTSTATUS_SORT | counters] that measure the number
** of times it has performed specific operations.)^  These counters can
** be used to monitor the performance characteristics of the prepared
** statements.  For example, if the number of table steps greatly exceeds
** the number of table searches or result rows, that would tend to indicate
** that the prepared statement is using a full table scan rather than
** an index.  
**
** ^(This interface is used to retrieve and reset counter values from
** a [prepared statement].  The first argument is the prepared statement
** object to be interrogated.  The second argument
** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter]
** to be interrogated.)^
** ^The current value of the requested counter is returned.
** ^If the resetFlg is true, then the counter is reset to zero after this
** interface call returns.
**
** See also: [sqlite3_status()] and [sqlite3_db_status()].
*/
SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);

/*
** CAPI3REF: Status Parameters for prepared statements
** EXPERIMENTAL
**
** These preprocessor macros define integer codes that name counter
** values associated with the [sqlite3_stmt_status()] interface.
** The meanings of the various counters are as follows:
**
** <dl>
** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
** <dd>^This is the number of times that SQLite has stepped forward in
** a table as part of a full table scan.  Large numbers for this counter
** may indicate opportunities for performance improvement through 
** careful use of indices.</dd>
**
** <dt>SQLITE_STMTSTATUS_SORT</dt>
** <dd>^This is the number of sort operations that have occurred.
** A non-zero value in this counter may indicate an opportunity to
** improvement performance through careful use of indices.</dd>
**
** </dl>
*/
#define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
#define SQLITE_STMTSTATUS_SORT              2
................................................................................
typedef struct sqlite3_pcache sqlite3_pcache;

/*
** CAPI3REF: Application Defined Page Cache.
** KEYWORDS: {page cache}
** EXPERIMENTAL
**
** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can
** register an alternative page cache implementation by passing in an 
** instance of the sqlite3_pcache_methods structure.)^ The majority of the 
** heap memory used by SQLite is used by the page cache to cache data read 
** from, or ready to be written to, the database file. By implementing a 
** custom page cache using this API, an application can control more 
** precisely the amount of memory consumed by SQLite, the way in which 
** that memory is allocated and released, and the policies used to 
** determine exactly which parts of a database file are cached and for 
** how long.
**
** ^(The contents of the sqlite3_pcache_methods structure are copied to an
** internal buffer by SQLite within the call to [sqlite3_config].  Hence
** the application may discard the parameter after the call to
** [sqlite3_config()] returns.)^
**
** ^The xInit() method is called once for each call to [sqlite3_initialize()]
** (usually only once during the lifetime of the process). ^(The xInit()
** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^
** ^The xInit() method can set up up global structures and/or any mutexes
** required by the custom page cache implementation. 
**
** ^The xShutdown() method is called from within [sqlite3_shutdown()], 
** if the application invokes this API. It can be used to clean up 
** any outstanding resources before process shutdown, if required.
**
** ^SQLite holds a [SQLITE_MUTEX_RECURSIVE] mutex when it invokes
** the xInit method, so the xInit method need not be threadsafe.  ^The
** xShutdown method is only called from [sqlite3_shutdown()] so it does
** not need to be threadsafe either.  All other methods must be threadsafe
** in multithreaded applications.
**
** ^SQLite will never invoke xInit() more than once without an intervening
** call to xShutdown().
**
** ^The xCreate() method is used to construct a new cache instance.  SQLite
** will typically create one cache instance for each open database file,
** though this is not guaranteed. ^The
** first parameter, szPage, is the size in bytes of the pages that must
** be allocated by the cache.  ^szPage will not be a power of two.  ^szPage
** will the page size of the database file that is to be cached plus an
** increment (here called "R") of about 100 or 200.  ^SQLite will use the
** extra R bytes on each page to store metadata about the underlying
** database page on disk.  The value of R depends
** on the SQLite version, the target platform, and how SQLite was compiled.
** ^R is constant for a particular build of SQLite.  ^The second argument to
** xCreate(), bPurgeable, is true if the cache being created will
** be used to cache database pages of a file stored on disk, or
** false if it is used for an in-memory database. ^The cache implementation
** does not have to do anything special based with the value of bPurgeable;
** it is purely advisory.  ^On a cache where bPurgeable is false, SQLite will
** never invoke xUnpin() except to deliberately delete a page.
** ^In other words, a cache created with bPurgeable set to false will
** never contain any unpinned pages.
**
** ^(The xCachesize() method may be called at any time by SQLite to set the
** suggested maximum cache-size (number of pages stored by) the cache
** instance passed as the first argument. This is the value configured using
** the SQLite "[PRAGMA cache_size]" command.)^  ^As with the bPurgeable
** parameter, the implementation is not required to do anything with this
** value; it is advisory only.
**
** ^The xPagecount() method should return the number of pages currently
** stored in the cache.
** 
** ^The xFetch() method is used to fetch a page and return a pointer to it. 
** ^A 'page', in this context, is a buffer of szPage bytes aligned at an
** 8-byte boundary. ^The page to be fetched is determined by the key. ^The
** mimimum key value is 1. After it has been retrieved using xFetch, the page 
** is considered to be "pinned".
**
** ^If the requested page is already in the page cache, then the page cache
** implementation must return a pointer to the page buffer with its content
** intact.  ^(If the requested page is not already in the cache, then the
** behavior of the cache implementation is determined by the value of the
** createFlag parameter passed to xFetch, according to the following table:
**
** <table border=1 width=85% align=center>
** <tr><th> createFlag <th> Behaviour when page is not already in cache
** <tr><td> 0 <td> Do not allocate a new page.  Return NULL.
** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
**                 Otherwise return NULL.
** <tr><td> 2 <td> Make every effort to allocate a new page.  Only return
**                 NULL if allocating a new page is effectively impossible.
** </table>)^
**
** SQLite will normally invoke xFetch() with a createFlag of 0 or 1.  If
** a call to xFetch() with createFlag==1 returns NULL, then SQLite will
** attempt to unpin one or more cache pages by spilling the content of
** pinned pages to disk and synching the operating system disk cache. After
** attempting to unpin pages, the xFetch() method will be invoked again with
** a createFlag of 2.
**
** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
** as its second argument. ^(If the third parameter, discard, is non-zero,
** then the page should be evicted from the cache. In this case SQLite 
** assumes that the next time the page is retrieved from the cache using
** the xFetch() method, it will be zeroed.)^ ^If the discard parameter is
** zero, then the page is considered to be unpinned. ^The cache implementation
** may choose to evict unpinned pages at any time.
**
** ^(The cache is not required to perform any reference counting. A single 
** call to xUnpin() unpins the page regardless of the number of prior calls 
** to xFetch().)^
**
** ^The xRekey() method is used to change the key value associated with the
** page passed as the second argument from oldKey to newKey. ^If the cache
** previously contains an entry associated with newKey, it should be
** discarded. ^Any prior cache entry associated with newKey is guaranteed not
** to be pinned.
**
** ^When SQLite calls the xTruncate() method, the cache must discard all
** existing cache entries with page numbers (keys) greater than or equal
** to the value of the iLimit parameter passed to xTruncate(). ^If any
** of these pages are pinned, they are implicitly unpinned, meaning that
** they can be safely discarded.
**
** ^The xDestroy() method is used to delete a cache allocated by xCreate().
** All resources associated with the specified cache should be freed. ^After
** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
** handle invalid, and will not use it with any other sqlite3_pcache_methods
** functions.
*/
typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
struct sqlite3_pcache_methods {
  void *pArg;
................................................................................
};

/*
** CAPI3REF: Online Backup Object
** EXPERIMENTAL
**
** The sqlite3_backup object records state information about an ongoing
** online backup operation.  ^The sqlite3_backup object is created by
** a call to [sqlite3_backup_init()] and is destroyed by a call to
** [sqlite3_backup_finish()].
**
** See Also: [Using the SQLite Online Backup API]
*/
typedef struct sqlite3_backup sqlite3_backup;

/*
** CAPI3REF: Online Backup API.
** EXPERIMENTAL
**
** The backup API copies the content of one database into another.
** It is useful either for creating backups of databases or
** for copying in-memory databases to or from persistent files. 
**
** See Also: [Using the SQLite Online Backup API]
**
** ^Exclusive access is required to the destination database for the 
** duration of the operation. ^However the source database is only
** read-locked while it is actually being read; it is not locked
** continuously for the entire backup operation. ^Thus, the backup may be
** performed on a live source database without preventing other users from
** reading or writing to the source database while the backup is underway.
** 
** ^(To perform a backup operation: 
**   <ol>
**     <li><b>sqlite3_backup_init()</b> is called once to initialize the
**         backup, 
**     <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 
**         the data between the two databases, and finally
**     <li><b>sqlite3_backup_finish()</b> is called to release all resources 
**         associated with the backup operation. 
**   </ol>)^
** There should be exactly one call to sqlite3_backup_finish() for each
** successful call to sqlite3_backup_init().
**
** <b>sqlite3_backup_init()</b>
**
** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 
** [database connection] associated with the destination database 
** and the database name, respectively.
** ^The database name is "main" for the main database, "temp" for the
** temporary database, or the name specified after the AS keyword in
** an [ATTACH] statement for an attached database.
** ^The S and M arguments passed to 
** sqlite3_backup_init(D,N,S,M) identify the [database connection]
** and database name of the source database, respectively.

** ^The source and destination [database connections] (parameters S and D)
** must be different or else sqlite3_backup_init(D,N,S,M) will file with
** an error.
**
** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
** returned and an error code and error message are store3d in the

** destination [database connection] D.
** ^The error code and message for the failed call to sqlite3_backup_init()
** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
** [sqlite3_errmsg16()] functions.
** ^A successful call to sqlite3_backup_init() returns a pointer to an
** [sqlite3_backup] object.
** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
** sqlite3_backup_finish() functions to perform the specified backup 
** operation.
**
** <b>sqlite3_backup_step()</b>
**
** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 
** the source and destination databases specified by [sqlite3_backup] object B.

** ^If N is negative, all remaining source pages are copied. 
** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
** are still more pages to be copied, then the function resturns [SQLITE_OK].
** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
** from source to destination, then it returns [SQLITE_DONE].
** ^If an error occurs while running sqlite3_backup_step(B,N),
** then an [error code] is returned. ^As well as [SQLITE_OK] and
** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
**
** ^The sqlite3_backup_step() might return [SQLITE_READONLY] if the destination
** database was opened read-only or if
** the destination is an in-memory database with a different page size
** from the source database.
**
** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
** the [sqlite3_busy_handler | busy-handler function]
** is invoked (if one is specified). ^If the 
** busy-handler returns non-zero before the lock is available, then 
** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
** sqlite3_backup_step() can be retried later. ^If the source
** [database connection]
** is being used to write to the source database when sqlite3_backup_step()
** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
** case the call to sqlite3_backup_step() can be retried later on. ^(If
** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
** [SQLITE_READONLY] is returned, then 
** there is no point in retrying the call to sqlite3_backup_step(). These 
** errors are considered fatal.)^  The application must accept 
** that the backup operation has failed and pass the backup operation handle 
** to the sqlite3_backup_finish() to release associated resources.
**
** ^The first call to sqlite3_backup_step() obtains an exclusive lock
** on the destination file. ^The exclusive lock is not released until either 
** sqlite3_backup_finish() is called or the backup operation is complete 
** and sqlite3_backup_step() returns [SQLITE_DONE].  ^Every call to
** sqlite3_backup_step() obtains a [shared lock] on the source database that
** lasts for the duration of the sqlite3_backup_step() call.
** ^Because the source database is not locked between calls to
** sqlite3_backup_step(), the source database may be modified mid-way
** through the backup process.  ^If the source database is modified by an
** external process or via a database connection other than the one being
** used by the backup operation, then the backup will be automatically
** restarted by the next call to sqlite3_backup_step(). ^If the source 
** database is modified by the using the same database connection as is used
** by the backup operation, then the backup database is automatically
** updated at the same time.
**
** <b>sqlite3_backup_finish()</b>
**
** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 
** application wishes to abandon the backup operation, the application
** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
** ^The sqlite3_backup_finish() interfaces releases all
** resources associated with the [sqlite3_backup] object. 
** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
** active write-transaction on the destination database is rolled back.
** The [sqlite3_backup] object is invalid
** and may not be used following a call to sqlite3_backup_finish().
**
** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
** sqlite3_backup_step() errors occurred, regardless or whether or not

** sqlite3_backup_step() completed.
** ^If an out-of-memory condition or IO error occurred during any prior
** sqlite3_backup_step() call on the same [sqlite3_backup] object, then


** sqlite3_backup_finish() returns the corresponding [error code].
**
** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
** is not a permanent error and does not affect the return value of
** sqlite3_backup_finish().
**
** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b>
**
** ^Each call to sqlite3_backup_step() sets two values inside
** the [sqlite3_backup] object: the number of pages still to be backed

** up and the total number of pages in the source databae file.
** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces
** retrieve these two values, respectively.
**
** ^The values returned by these functions are only updated by
** sqlite3_backup_step(). ^If the source database is modified during a backup
** operation, then the values are not updated to account for any extra
** pages that need to be updated or the size of the source database file
** changing.
**
** <b>Concurrent Usage of Database Handles</b>
**
** ^The source [database connection] may be used by the application for other
** purposes while a backup operation is underway or being initialized.
** ^If SQLite is compiled and configured to support threadsafe database
** connections, then the source database connection may be used concurrently
** from within other threads.
**
** However, the application must guarantee that the destination 
** [database connection] is not passed to any other API (by any thread) after 
** sqlite3_backup_init() is called and before the corresponding call to
** sqlite3_backup_finish().  SQLite does not currently check to see
** if the application incorrectly accesses the destination [database connection]
** and so no error code is reported, but the operations may malfunction

** nevertheless.  Use of the destination database connection while a
** backup is in progress might also also cause a mutex deadlock.
**
** If running in [shared cache mode], the application must
** guarantee that the shared cache used by the destination database
** is not accessed while the backup is running. In practice this means
** that the application must guarantee that the disk file being 
** backed up to is not accessed by any connection within the process,
** not just the specific connection that was passed to sqlite3_backup_init().
**
** The [sqlite3_backup] object itself is partially threadsafe. Multiple 
** threads may safely make multiple concurrent calls to sqlite3_backup_step().
** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
** APIs are not strictly speaking threadsafe. If they are invoked at the
................................................................................
int sqlite3_backup_remaining(sqlite3_backup *p);
int sqlite3_backup_pagecount(sqlite3_backup *p);

/*
** CAPI3REF: Unlock Notification
** EXPERIMENTAL
**
** ^When running in shared-cache mode, a database operation may fail with
** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
** individual tables within the shared-cache cannot be obtained. See
** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 
** ^This API may be used to register a callback that SQLite will invoke 
** when the connection currently holding the required lock relinquishes it.
** ^This API is only available if the library was compiled with the
** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
**
** See Also: [Using the SQLite Unlock Notification Feature].
**
** ^Shared-cache locks are released when a database connection concludes
** its current transaction, either by committing it or rolling it back. 
**
** ^When a connection (known as the blocked connection) fails to obtain a
** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
** identity of the database connection (the blocking connection) that
** has locked the required resource is stored internally. ^After an 
** application receives an SQLITE_LOCKED error, it may call the
** sqlite3_unlock_notify() method with the blocked connection handle as 
** the first argument to register for a callback that will be invoked
** when the blocking connections current transaction is concluded. ^The
** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
** call that concludes the blocking connections transaction.
**
** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
** there is a chance that the blocking connection will have already
** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
** If this happens, then the specified callback is invoked immediately,
** from within the call to sqlite3_unlock_notify().)^
**
** ^If the blocked connection is attempting to obtain a write-lock on a
** shared-cache table, and more than one other connection currently holds
** a read-lock on the same table, then SQLite arbitrarily selects one of 
** the other connections to use as the blocking connection.
**
** ^(There may be at most one unlock-notify callback registered by a 
** blocked connection. If sqlite3_unlock_notify() is called when the
** blocked connection already has a registered unlock-notify callback,
** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
** called with a NULL pointer as its second argument, then any existing
** unlock-notify callback is cancelled. ^The blocked connections 
** unlock-notify callback may also be canceled by closing the blocked
** connection using [sqlite3_close()].
**
** The unlock-notify callback is not reentrant. If an application invokes
** any sqlite3_xxx API functions from within an unlock-notify callback, a
** crash or deadlock may be the result.
**
** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
** returns SQLITE_OK.
**
** <b>Callback Invocation Details</b>
**
** When an unlock-notify callback is registered, the application provides a 
** single void* pointer that is passed to the callback when it is invoked.
** However, the signature of the callback function allows SQLite to pass
** it an array of void* context pointers. The first argument passed to
** an unlock-notify callback is a pointer to an array of void* pointers,
** and the second is the number of entries in the array.
**
** When a blocking connections transaction is concluded, there may be
** more than one blocked connection that has registered for an unlock-notify
** callback. ^If two or more such blocked connections have specified the
** same callback function, then instead of invoking the callback function
** multiple times, it is invoked once with the set of void* context pointers
** specified by the blocked connections bundled together into an array.
** This gives the application an opportunity to prioritize any actions 
** related to the set of unblocked database connections.
**
** <b>Deadlock Detection</b>
................................................................................
** action (a reasonable assumption), then using this API may cause the
** application to deadlock. For example, if connection X is waiting for
** connection Y's transaction to be concluded, and similarly connection
** Y is waiting on connection X's transaction, then neither connection
** will proceed and the system may remain deadlocked indefinitely.
**
** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
** detection. ^If a given call to sqlite3_unlock_notify() would put the
** system in a deadlocked state, then SQLITE_LOCKED is returned and no
** unlock-notify callback is registered. The system is said to be in
** a deadlocked state if connection A has registered for an unlock-notify
** callback on the conclusion of connection B's transaction, and connection
** B has itself registered for an unlock-notify callback when connection
** A's transaction is concluded. ^Indirect deadlock is also detected, so
** the system is also considered to be deadlocked if connection B has
** registered for an unlock-notify callback on the conclusion of connection
** C's transaction, where connection C is waiting on connection A. ^Any
** number of levels of indirection are allowed.
**
** <b>The "DROP TABLE" Exception</b>
**
** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 
** always appropriate to call sqlite3_unlock_notify(). There is however,
** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
................................................................................
** that belong to the same connection. If there are, SQLITE_LOCKED is
** returned. In this case there is no "blocking connection", so invoking
** sqlite3_unlock_notify() results in the unlock-notify callback being
** invoked immediately. If the application then re-attempts the "DROP TABLE"
** or "DROP INDEX" query, an infinite loop might be the result.
**
** One way around this problem is to check the extended error code returned
** by an sqlite3_step() call. ^(If there is a blocking connection, then the
** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
** the special "DROP TABLE/INDEX" case, the extended error code is just 
** SQLITE_LOCKED.)^
*/
int sqlite3_unlock_notify(
  sqlite3 *pBlocked,                          /* Waiting connection */
  void (*xNotify)(void **apArg, int nArg),    /* Callback function to invoke */
  void *pNotifyArg                            /* Argument to pass to xNotify */
);


/*
** CAPI3REF: String Comparison
** EXPERIMENTAL
**
** ^The [sqlite3_strnicmp()] API allows applications and extensions to
** compare the contents of two buffers containing UTF-8 strings in a
** case-indendent fashion, using the same definition of case independence 
** that SQLite uses internally when comparing identifiers.
*/
int sqlite3_strnicmp(const char *, const char *, int);

/*

#define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
#define WHERE_OMIT_OPEN        0x0010 /* Table cursor are already open */
#define WHERE_OMIT_CLOSE       0x0020 /* Omit close of table & index cursors */
#define WHERE_FORCE_TABLE      0x0040 /* Do not use an index-only search */


/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
struct WhereInfo {
  Parse *pParse;       /* Parsing and code generating context */
  u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */

  SrcList *pTabList;             /* List of tables in the join */
  int iTop;                      /* The very beginning of the WHERE loop */
  int iContinue;                 /* Jump here to continue with next record */
  int iBreak;                    /* Jump here to break out of the loop */
  int nLevel;                    /* Number of nested loop */
  struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
  WhereLevel a[1];               /* Information about each nest loop in WHERE */

#define WHERE_ORDERBY_MIN      0x0001 /* ORDER BY processing for min() func */
#define WHERE_ORDERBY_MAX      0x0002 /* ORDER BY processing for max() func */
#define WHERE_ONEPASS_DESIRED  0x0004 /* Want to do one-pass UPDATE/DELETE */
#define WHERE_DUPLICATES_OK    0x0008 /* Ok to return a row more than once */
#define WHERE_OMIT_OPEN        0x0010 /* Table cursor are already open */
#define WHERE_OMIT_CLOSE       0x0020 /* Omit close of table & index cursors */
#define WHERE_FORCE_TABLE      0x0040 /* Do not use an index-only search */
#define WHERE_ONETABLE_ONLY    0x0080 /* Only code the 1st table in pTabList */

/*
** The WHERE clause processing routine has two halves.  The
** first part does the start of the WHERE loop and the second
** half does the tail of the WHERE loop.  An instance of
** this structure is returned by the first half and passed
** into the second half to give some continuity.
*/
struct WhereInfo {
  Parse *pParse;       /* Parsing and code generating context */
  u16 wctrlFlags;      /* Flags originally passed to sqlite3WhereBegin() */
  u8 okOnePass;        /* Ok to use one-pass algorithm for UPDATE or DELETE */
  u8 untestedTerms;    /* Not all WHERE terms resolved by outer loop */
  SrcList *pTabList;             /* List of tables in the join */
  int iTop;                      /* The very beginning of the WHERE loop */
  int iContinue;                 /* Jump here to continue with next record */
  int iBreak;                    /* Jump here to break out of the loop */
  int nLevel;                    /* Number of nested loop */
  struct WhereClause *pWC;       /* Decomposition of the WHERE clause */
  WhereLevel a[1];               /* Information about each nest loop in WHERE */

  x += y * (*q++);
  *v = (sqlite_int64) x;
  return (int) (q - (unsigned char *)p);
}


/*
** USAGE:  read_varint BLOB VARNAME
**
** Read a varint from the start of BLOB. Set variable VARNAME to contain
** the interpreted value. Return the number of bytes of BLOB consumed.
*/
static int read_varint(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int nBlob;
  unsigned char *zBlob;
................................................................................
  } aObjCmd[] = {
     { "hexio_read",                   hexio_read            },
     { "hexio_write",                  hexio_write           },
     { "hexio_get_int",                hexio_get_int         },
     { "hexio_render_int16",           hexio_render_int16    },
     { "hexio_render_int32",           hexio_render_int32    },
     { "utf8_to_utf8",                 utf8_to_utf8          },
     { "read_varint",                  read_varint           },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
  }
  return TCL_OK;
}

  x += y * (*q++);
  *v = (sqlite_int64) x;
  return (int) (q - (unsigned char *)p);
}


/*
** USAGE:  read_fts3varint BLOB VARNAME
**
** Read a varint from the start of BLOB. Set variable VARNAME to contain
** the interpreted value. Return the number of bytes of BLOB consumed.
*/
static int read_fts3varint(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int nBlob;
  unsigned char *zBlob;
................................................................................
  } aObjCmd[] = {
     { "hexio_read",                   hexio_read            },
     { "hexio_write",                  hexio_write           },
     { "hexio_get_int",                hexio_get_int         },
     { "hexio_render_int16",           hexio_render_int16    },
     { "hexio_render_int32",           hexio_render_int32    },
     { "utf8_to_utf8",                 utf8_to_utf8          },
     { "read_fts3varint",              read_fts3varint       },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, 0, 0);
  }
  return TCL_OK;
}

      testcase( z[0]=='\r' );
      for(i=1; sqlite3Isspace(z[i]); i++){}
      *tokenType = TK_SPACE;
      return i;
    }
    case '-': {
      if( z[1]=='-' ){

        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
        *tokenType = TK_SPACE;
        return i;
      }
      *tokenType = TK_MINUS;
      return 1;
    }
    case '(': {
      *tokenType = TK_LP;
................................................................................
      return 1;
    }
    case '/': {
      if( z[1]!='*' || z[2]==0 ){
        *tokenType = TK_SLASH;
        return 1;
      }

      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
      if( c ) i++;
      *tokenType = TK_SPACE;
      return i;
    }
    case '%': {
      *tokenType = TK_REM;
      return 1;
    }
    case '=': {

      testcase( z[0]=='\r' );
      for(i=1; sqlite3Isspace(z[i]); i++){}
      *tokenType = TK_SPACE;
      return i;
    }
    case '-': {
      if( z[1]=='-' ){
        /* IMP: R-15891-05542 -- syntax diagram for comments */
        for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
        *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
        return i;
      }
      *tokenType = TK_MINUS;
      return 1;
    }
    case '(': {
      *tokenType = TK_LP;
................................................................................
      return 1;
    }
    case '/': {
      if( z[1]!='*' || z[2]==0 ){
        *tokenType = TK_SLASH;
        return 1;
      }
      /* IMP: R-15891-05542 -- syntax diagram for comments */
      for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
      if( c ) i++;
      *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
      return i;
    }
    case '%': {
      *tokenType = TK_REM;
      return 1;
    }
    case '=': {

** same context that was returned on prior calls.
*/
void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
  Mem *pMem;
  assert( p && p->pFunc && p->pFunc->xStep );
  assert( sqlite3_mutex_held(p->s.db->mutex) );
  pMem = p->pMem;

  if( (pMem->flags & MEM_Agg)==0 ){
    if( nByte==0 ){
      sqlite3VdbeMemReleaseExternal(pMem);
      pMem->flags = MEM_Null;
      pMem->z = 0;
    }else{
      sqlite3VdbeMemGrow(pMem, nByte, 0);
      pMem->flags = MEM_Agg;
      pMem->u.pDef = p->pFunc;

** same context that was returned on prior calls.
*/
void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
  Mem *pMem;
  assert( p && p->pFunc && p->pFunc->xStep );
  assert( sqlite3_mutex_held(p->s.db->mutex) );
  pMem = p->pMem;
  testcase( nByte<0 );
  if( (pMem->flags & MEM_Agg)==0 ){
    if( nByte<=0 ){
      sqlite3VdbeMemReleaseExternal(pMem);
      pMem->flags = MEM_Null;
      pMem->z = 0;
    }else{
      sqlite3VdbeMemGrow(pMem, nByte, 0);
      pMem->flags = MEM_Agg;
      pMem->u.pDef = p->pFunc;

    z[j] = 0;
    sqlite3IoTrace("SQL %s\n", z);
  }
}
#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */

/*
** Allocate space from a fixed size buffer.  Make *pp point to the
** allocated space.  (Note:  pp is a char* rather than a void** to
** work around the pointer aliasing rules of C.)  *pp should initially
** be zero.  If *pp is not zero, that means that the space has already

** been allocated and this routine is a noop.



**
** nByte is the number of bytes of space needed.
**
** *ppFrom point to available space and pEnd points to the end of the
** available space.

**
** *pnByte is a counter of the number of bytes of space that have failed
** to allocate.  If there is insufficient space in *ppFrom to satisfy the
** request, then increment *pnByte by the amount of the request.
*/
static void allocSpace(
  char *pp,            /* IN/OUT: Set *pp to point to allocated buffer */
  int nByte,           /* Number of bytes to allocate */
  u8 **ppFrom,         /* IN/OUT: Allocate from *ppFrom */
  u8 *pEnd,            /* Pointer to 1 byte past the end of *ppFrom buffer */
  int *pnByte          /* If allocation cannot be made, increment *pnByte */
){
  assert( EIGHT_BYTE_ALIGNMENT(*ppFrom) );
  if( (*(void**)pp)==0 ){
    nByte = ROUND8(nByte);
    if( &(*ppFrom)[nByte] <= pEnd ){
      *(void**)pp = (void *)*ppFrom;
      *ppFrom += nByte;
    }else{
      *pnByte += nByte;
    }
  }

}

/*
** Prepare a virtual machine for execution.  This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqlite3VdbeExec().  
................................................................................

  /* Allocate space for memory registers, SQL variables, VDBE cursors and 
  ** an array to marshal SQL function arguments in. This is only done the
  ** first time this function is called for a given VDBE, not when it is
  ** being called from sqlite3_reset() to reset the virtual machine.
  */
  if( nVar>=0 && ALWAYS(db->mallocFailed==0) ){
    u8 *zCsr = (u8 *)&p->aOp[p->nOp];
    u8 *zEnd = (u8 *)&p->aOp[p->nOpAlloc];
    int nByte;

    resolveP2Values(p, &nArg);
    p->usesStmtJournal = (u8)usesStmtJournal;
    if( isExplain && nMem<10 ){
      nMem = 10;
    }
    memset(zCsr, 0, zEnd-zCsr);
    zCsr += (zCsr - (u8*)0)&7;
    assert( EIGHT_BYTE_ALIGNMENT(zCsr) );











    do {
      nByte = 0;
      allocSpace((char*)&p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
      allocSpace((char*)&p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
      allocSpace((char*)&p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
      allocSpace((char*)&p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
      allocSpace((char*)&p->apCsr, 

                 nCursor*sizeof(VdbeCursor*), &zCsr, zEnd, &nByte
      );
      if( nByte ){
        p->pFree = sqlite3DbMallocZero(db, nByte);
      }
      zCsr = p->pFree;
      zEnd = &zCsr[nByte];
    }while( nByte && !db->mallocFailed );

................................................................................
    ** master journal file. If an error occurs at this point close
    ** and delete the master journal file. All the individual journal files
    ** still have 'null' as the master journal pointer, so they will roll
    ** back independently if a failure occurs.
    */
    for(i=0; i<db->nDb; i++){
      Btree *pBt = db->aDb[i].pBt;
      if( i==1 ) continue;   /* Ignore the TEMP database */
      if( sqlite3BtreeIsInTrans(pBt) ){
        char const *zFile = sqlite3BtreeGetJournalname(pBt);

        if( zFile[0]==0 ) continue;  /* Ignore :memory: databases */

        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
          needSync = 1;
        }
        rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
        offset += sqlite3Strlen30(zFile)+1;
        if( rc!=SQLITE_OK ){
          sqlite3OsCloseFree(pMaster);

    z[j] = 0;
    sqlite3IoTrace("SQL %s\n", z);
  }
}
#endif /* !SQLITE_OMIT_TRACE && SQLITE_ENABLE_IOTRACE */

/*
** Allocate space from a fixed size buffer and return a pointer to
** that space.  If insufficient space is available, return NULL.
**
** The pBuf parameter is the initial value of a pointer which will
** receive the new memory.  pBuf is normally NULL.  If pBuf is not
** NULL, it means that memory space has already been allocated and that
** this routine should not allocate any new memory.  When pBuf is not
** NULL simply return pBuf.  Only allocate new memory space when pBuf
** is NULL.
**
** nByte is the number of bytes of space needed.
**
** *ppFrom points to available space and pEnd points to the end of the
** available space.  When space is allocated, *ppFrom is advanced past
** the end of the allocated space.
**
** *pnByte is a counter of the number of bytes of space that have failed
** to allocate.  If there is insufficient space in *ppFrom to satisfy the
** request, then increment *pnByte by the amount of the request.
*/
static void *allocSpace(
  void *pBuf,          /* Where return pointer will be stored */
  int nByte,           /* Number of bytes to allocate */
  u8 **ppFrom,         /* IN/OUT: Allocate from *ppFrom */
  u8 *pEnd,            /* Pointer to 1 byte past the end of *ppFrom buffer */
  int *pnByte          /* If allocation cannot be made, increment *pnByte */
){
  assert( EIGHT_BYTE_ALIGNMENT(*ppFrom) );
  if( pBuf ) return pBuf;
  nByte = ROUND8(nByte);
  if( &(*ppFrom)[nByte] <= pEnd ){
    pBuf = (void*)*ppFrom;
    *ppFrom += nByte;
  }else{
    *pnByte += nByte;
  }

  return pBuf;
}

/*
** Prepare a virtual machine for execution.  This involves things such
** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqlite3VdbeExec().  
................................................................................

  /* Allocate space for memory registers, SQL variables, VDBE cursors and 
  ** an array to marshal SQL function arguments in. This is only done the
  ** first time this function is called for a given VDBE, not when it is
  ** being called from sqlite3_reset() to reset the virtual machine.
  */
  if( nVar>=0 && ALWAYS(db->mallocFailed==0) ){
    u8 *zCsr = (u8 *)&p->aOp[p->nOp];       /* Memory avaliable for alloation */
    u8 *zEnd = (u8 *)&p->aOp[p->nOpAlloc];  /* First byte past available mem */
    int nByte;                              /* How much extra memory needed */

    resolveP2Values(p, &nArg);
    p->usesStmtJournal = (u8)usesStmtJournal;
    if( isExplain && nMem<10 ){
      nMem = 10;
    }
    memset(zCsr, 0, zEnd-zCsr);
    zCsr += (zCsr - (u8*)0)&7;
    assert( EIGHT_BYTE_ALIGNMENT(zCsr) );

    /* Memory for registers, parameters, cursor, etc, is allocated in two
    ** passes.  On the first pass, we try to reuse unused space at the 
    ** end of the opcode array.  If we are unable to satisfy all memory
    ** requirements by reusing the opcode array tail, then the second
    ** pass will fill in the rest using a fresh allocation.  
    **
    ** This two-pass approach that reuses as much memory as possible from
    ** the leftover space at the end of the opcode array can significantly
    ** reduce the amount of memory held by a prepared statement.
    */
    do {
      nByte = 0;
      p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
      p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
      p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
      p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);

      p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
                            &zCsr, zEnd, &nByte);

      if( nByte ){
        p->pFree = sqlite3DbMallocZero(db, nByte);
      }
      zCsr = p->pFree;
      zEnd = &zCsr[nByte];
    }while( nByte && !db->mallocFailed );

................................................................................
    ** master journal file. If an error occurs at this point close
    ** and delete the master journal file. All the individual journal files
    ** still have 'null' as the master journal pointer, so they will roll
    ** back independently if a failure occurs.
    */
    for(i=0; i<db->nDb; i++){
      Btree *pBt = db->aDb[i].pBt;

      if( sqlite3BtreeIsInTrans(pBt) ){
        char const *zFile = sqlite3BtreeGetJournalname(pBt);
        if( zFile==0 || zFile[0]==0 ){
          continue;  /* Ignore TEMP and :memory: databases */
        }
        if( !needSync && !sqlite3BtreeSyncDisabled(pBt) ){
          needSync = 1;
        }
        rc = sqlite3OsWrite(pMaster, zFile, sqlite3Strlen30(zFile)+1, offset);
        offset += sqlite3Strlen30(zFile)+1;
        if( rc!=SQLITE_OK ){
          sqlite3OsCloseFree(pMaster);

  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
  if( pParse==0 ){
    rc = SQLITE_NOMEM;
  }else{
    pParse->declareVtab = 1;
    pParse->db = db;
  
    if( 
        SQLITE_OK == sqlite3RunParser(pParse, zCreateTable, &zErr) && 
        pParse->pNewTable && 

        !pParse->pNewTable->pSelect && 
        (pParse->pNewTable->tabFlags & TF_Virtual)==0
    ){
      if( !pTab->aCol ){
        pTab->aCol = pParse->pNewTable->aCol;
        pTab->nCol = pParse->pNewTable->nCol;
        pParse->pNewTable->nCol = 0;
        pParse->pNewTable->aCol = 0;
      }
      db->pVTab = 0;
    } else {
      sqlite3Error(db, SQLITE_ERROR, zErr);
      sqlite3DbFree(db, zErr);
      rc = SQLITE_ERROR;
    }
    pParse->declareVtab = 0;
  
    if( pParse->pVdbe ){

  pParse = sqlite3StackAllocZero(db, sizeof(*pParse));
  if( pParse==0 ){
    rc = SQLITE_NOMEM;
  }else{
    pParse->declareVtab = 1;
    pParse->db = db;
  

    if( SQLITE_OK==sqlite3RunParser(pParse, zCreateTable, &zErr) 
     && pParse->pNewTable
     && !db->mallocFailed
     && !pParse->pNewTable->pSelect
     && (pParse->pNewTable->tabFlags & TF_Virtual)==0
    ){
      if( !pTab->aCol ){
        pTab->aCol = pParse->pNewTable->aCol;
        pTab->nCol = pParse->pNewTable->nCol;
        pParse->pNewTable->nCol = 0;
        pParse->pNewTable->aCol = 0;
      }
      db->pVTab = 0;
    }else{
      sqlite3Error(db, SQLITE_ERROR, zErr);
      sqlite3DbFree(db, zErr);
      rc = SQLITE_ERROR;
    }
    pParse->declareVtab = 0;
  
    if( pParse->pVdbe ){

    **          Return     2                # Jump back to the Gosub
    **
    **       B: <after the loop>
    **
    */
    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
    WhereTerm *pFinal;     /* Final subterm within the OR-clause. */
    SrcList oneTab;        /* Shortened table list */

    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
    int regRowset = 0;                        /* Register for RowSet object */
    int regRowid = 0;                         /* Register holding rowid */
    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
    int iRetInit;                             /* Address of regReturn init */

    int ii;
   
    pTerm = pLevel->plan.u.pTerm;
    assert( pTerm!=0 );
    assert( pTerm->eOperator==WO_OR );
    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
    pOrWc = &pTerm->u.pOrInfo->wc;
    pFinal = &pOrWc->a[pOrWc->nTerm-1];



    /* Set up a SrcList containing just the table being scanned by this loop. */
    oneTab.nSrc = 1;
    oneTab.nAlloc = 1;
    oneTab.a[0] = *pTabItem;



















    /* Initialize the rowset register to contain NULL. An SQL NULL is 
    ** equivalent to an empty rowset.
    **
    ** Also initialize regReturn to contain the address of the instruction 
    ** immediately following the OP_Return at the bottom of the loop. This
    ** is required in a few obscure LEFT JOIN cases where control jumps
................................................................................
    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);

    for(ii=0; ii<pOrWc->nTerm; ii++){
      WhereTerm *pOrTerm = &pOrWc->a[ii];
      if( pOrTerm->leftCursor==iCur || pOrTerm->eOperator==WO_AND ){
        WhereInfo *pSubWInfo;          /* Info for single OR-term scan */
        /* Loop through table entries that match term pOrTerm. */
        pSubWInfo = sqlite3WhereBegin(pParse, &oneTab, pOrTerm->pExpr, 0,
                        WHERE_OMIT_OPEN | WHERE_OMIT_CLOSE | WHERE_FORCE_TABLE);

        if( pSubWInfo ){
          if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
            int r;
            r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, 
                                         regRowid, 0);
            sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset,
                                 sqlite3VdbeCurrentAddr(v)+2, r, iSet);
          }
          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);








          /* Finish the loop through table entries that match term pOrTerm. */
          sqlite3WhereEnd(pSubWInfo);
        }
      }
    }
    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
    /* sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset); */
    sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
    sqlite3VdbeResolveLabel(v, iLoopBody);

    pLevel->op = OP_Return;
    pLevel->p1 = regReturn;
    disableTerm(pLevel, pTerm);
  }else
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */

  {
    /* Case 5:  There is no usable index.  We must do a complete
    **          scan of the entire table.
    */
................................................................................
  */
  k = 0;
  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
    Expr *pE;
    testcase( pTerm->wtFlags & TERM_VIRTUAL );
    testcase( pTerm->wtFlags & TERM_CODED );
    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
    if( (pTerm->prereqAll & notReady)!=0 ) continue;





    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;
    }
    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
    k = 1;
................................................................................
    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
    VdbeComment((v, "record LEFT JOIN hit"));
    sqlite3ExprCacheClear(pParse);
    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
      testcase( pTerm->wtFlags & TERM_VIRTUAL );
      testcase( pTerm->wtFlags & TERM_CODED );
      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
      if( (pTerm->prereqAll & notReady)!=0 ) continue;



      assert( pTerm->pExpr );
      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
      pTerm->wtFlags |= TERM_CODED;
    }
  }
  sqlite3ReleaseTempReg(pParse, iReleaseReg);

................................................................................
  SrcList *pTabList,    /* A list of all tables to be scanned */
  Expr *pWhere,         /* The WHERE clause */
  ExprList **ppOrderBy, /* An ORDER BY clause, or NULL */
  u16 wctrlFlags        /* One of the WHERE_* flags defined in sqliteInt.h */
){
  int i;                     /* Loop counter */
  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */

  WhereInfo *pWInfo;         /* Will become the return value of this function */
  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
  Bitmask notReady;          /* Cursors that are not yet positioned */
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereClause *pWC;               /* Decomposition of the WHERE clause */
  struct SrcList_item *pTabItem;  /* A single entry from pTabList */
  WhereLevel *pLevel;             /* A single level in the pWInfo list */
................................................................................
  /* The number of tables in the FROM clause is limited by the number of
  ** bits in a Bitmask 
  */
  if( pTabList->nSrc>BMS ){
    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
    return 0;
  }








  /* Allocate and initialize the WhereInfo structure that will become the
  ** return value. A single allocation is used to store the WhereInfo
  ** struct, the contents of WhereInfo.a[], the WhereClause structure
  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
  ** some architectures. Hence the ROUND8() below.
  */
  db = pParse->db;
  nByteWInfo = ROUND8(sizeof(WhereInfo)+(pTabList->nSrc-1)*sizeof(WhereLevel));
  pWInfo = sqlite3DbMallocZero(db, 
      nByteWInfo + 
      sizeof(WhereClause) +
      sizeof(WhereMaskSet)
  );
  if( db->mallocFailed ){
    goto whereBeginError;
  }
  pWInfo->nLevel = pTabList->nSrc;
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
  pWInfo->pWC = pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
  pWInfo->wctrlFlags = wctrlFlags;
  pMaskSet = (WhereMaskSet*)&pWC[1];

................................................................................
  whereClauseInit(pWC, pParse, pMaskSet);
  sqlite3ExprCodeConstants(pParse, pWhere);
  whereSplit(pWC, pWhere, TK_AND);
    
  /* Special case: a WHERE clause that is constant.  Evaluate the
  ** expression and either jump over all of the code or fall thru.
  */
  if( pWhere && (pTabList->nSrc==0 || sqlite3ExprIsConstantNotJoin(pWhere)) ){
    sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, SQLITE_JUMPIFNULL);
    pWhere = 0;
  }

  /* Assign a bit from the bitmask to every term in the FROM clause.
  **
  ** When assigning bitmask values to FROM clause cursors, it must be
................................................................................
  ** bitmask for all tables to the left of the join.  Knowing the bitmask
  ** for all tables to the left of a left join is important.  Ticket #3015.
  **
  ** Configure the WhereClause.vmask variable so that bits that correspond
  ** to virtual table cursors are set. This is used to selectively disable 
  ** the OR-to-IN transformation in exprAnalyzeOrTerm(). It is not helpful 
  ** with virtual tables.





  */
  assert( pWC->vmask==0 && pMaskSet->n==0 );
  for(i=0; i<pTabList->nSrc; i++){
    createMask(pMaskSet, pTabList->a[i].iCursor);
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( ALWAYS(pTabList->a[i].pTab) && IsVirtual(pTabList->a[i].pTab) ){
      pWC->vmask |= ((Bitmask)1 << i);
................................................................................
  ** clause.
  */
  notReady = ~(Bitmask)0;
  pTabItem = pTabList->a;
  pLevel = pWInfo->a;
  andFlags = ~0;
  WHERETRACE(("*** Optimizer Start ***\n"));
  for(i=iFrom=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
    WhereCost bestPlan;         /* Most efficient plan seen so far */
    Index *pIdx;                /* Index for FROM table at pTabItem */
    int j;                      /* For looping over FROM tables */
    int bestJ = -1;             /* The value of j */
    Bitmask m;                  /* Bitmask value for j or bestJ */
    int isOptimal;              /* Iterator for optimal/non-optimal search */

................................................................................
    ** However, since the cost of a linear scan through table t2 is the same 
    ** as the cost of a linear scan through table t1, a simple greedy 
    ** algorithm may choose to use t2 for the outer loop, which is a much
    ** costlier approach.
    */
    for(isOptimal=1; isOptimal>=0 && bestJ<0; isOptimal--){
      Bitmask mask = (isOptimal ? 0 : notReady);
      assert( (pTabList->nSrc-iFrom)>1 || isOptimal );
      for(j=iFrom, pTabItem=&pTabList->a[j]; j<pTabList->nSrc; j++, pTabItem++){
        int doNotReorder;    /* True if this table should not be reordered */
        WhereCost sCost;     /* Cost information from best[Virtual]Index() */
        ExprList *pOrderBy;  /* ORDER BY clause for index to optimize */
  
        doNotReorder =  (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0;
        if( j!=iFrom && doNotReorder ) break;
        m = getMask(pMaskSet, pTabItem->iCursor);
................................................................................
    pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
  }

  /* Open all tables in the pTabList and any indices selected for
  ** searching those tables.
  */
  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
    Table *pTab;     /* Table to open */
    int iDb;         /* Index of database containing table/index */

#ifndef SQLITE_OMIT_EXPLAIN
    if( pParse->explain==2 ){
      char *zMsg;
      struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
................................................................................
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
  ** program.
  */
  notReady = ~(Bitmask)0;
  for(i=0; i<pTabList->nSrc; i++){
    notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady);
    pWInfo->iContinue = pWInfo->a[i].addrCont;
  }

#ifdef SQLITE_TEST  /* For testing and debugging use only */
  /* Record in the query plan information about the current table
  ** and the index used to access it (if any).  If the table itself
  ** is not used, its name is just '{}'.  If no index is used
  ** the index is listed as "{}".  If the primary key is used the
  ** index name is '*'.
  */
  for(i=0; i<pTabList->nSrc; i++){
    char *z;
    int n;
    pLevel = &pWInfo->a[i];
    pTabItem = &pTabList->a[pLevel->iFrom];
    z = pTabItem->zAlias;
    if( z==0 ) z = pTabItem->pTab->zName;
    n = sqlite3Strlen30(z);
................................................................................
  WhereLevel *pLevel;
  SrcList *pTabList = pWInfo->pTabList;
  sqlite3 *db = pParse->db;

  /* Generate loop termination code.
  */
  sqlite3ExprCacheClear(pParse);
  for(i=pTabList->nSrc-1; i>=0; i--){
    pLevel = &pWInfo->a[i];
    sqlite3VdbeResolveLabel(v, pLevel->addrCont);
    if( pLevel->op!=OP_Noop ){
      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
      sqlite3VdbeChangeP5(v, pLevel->p5);
    }
    if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
................................................................................
  /* The "break" point is here, just past the end of the outer loop.
  ** Set it.
  */
  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);

  /* Close all of the cursors that were opened by sqlite3WhereBegin.
  */

  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
    Table *pTab = pTabItem->pTab;
    assert( pTab!=0 );
    if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ) continue;
    if( (pWInfo->wctrlFlags & WHERE_OMIT_CLOSE)==0 ){
      if( !pWInfo->okOnePass && (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);

    **          Return     2                # Jump back to the Gosub
    **
    **       B: <after the loop>
    **
    */
    WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
    WhereTerm *pFinal;     /* Final subterm within the OR-clause. */
    SrcList *pOrTab;       /* Shortened table list or OR-clause generation */

    int regReturn = ++pParse->nMem;           /* Register used with OP_Gosub */
    int regRowset = 0;                        /* Register for RowSet object */
    int regRowid = 0;                         /* Register holding rowid */
    int iLoopBody = sqlite3VdbeMakeLabel(v);  /* Start of loop body */
    int iRetInit;                             /* Address of regReturn init */
    int untestedTerms = 0;             /* Some terms not completely tested */
    int ii;
   
    pTerm = pLevel->plan.u.pTerm;
    assert( pTerm!=0 );
    assert( pTerm->eOperator==WO_OR );
    assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
    pOrWc = &pTerm->u.pOrInfo->wc;
    pFinal = &pOrWc->a[pOrWc->nTerm-1];
    pLevel->op = OP_Return;
    pLevel->p1 = regReturn;



    /* Set up a new SrcList ni pOrTab containing the table being scanned
    ** by this loop in the a[0] slot and all notReady tables in a[1..] slots.
    ** This becomes the SrcList in the recursive call to sqlite3WhereBegin().
    */
    if( pWInfo->nLevel>1 ){
      int nNotReady;                 /* The number of notReady tables */
      struct SrcList_item *origSrc;     /* Original list of tables */
      nNotReady = pWInfo->nLevel - iLevel - 1;
      pOrTab = sqlite3StackAllocRaw(pParse->db,
                            sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
      if( pOrTab==0 ) return notReady;
      pOrTab->nSrc = pOrTab->nAlloc = nNotReady + 1;
      memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
      origSrc = pWInfo->pTabList->a;
      for(k=1; k<=nNotReady; k++){
        memcpy(&pOrTab->a[k], &origSrc[pLevel[k].iFrom], sizeof(pOrTab->a[k]));
      }
    }else{
      pOrTab = pWInfo->pTabList;
    }

    /* Initialize the rowset register to contain NULL. An SQL NULL is 
    ** equivalent to an empty rowset.
    **
    ** Also initialize regReturn to contain the address of the instruction 
    ** immediately following the OP_Return at the bottom of the loop. This
    ** is required in a few obscure LEFT JOIN cases where control jumps
................................................................................
    iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn);

    for(ii=0; ii<pOrWc->nTerm; ii++){
      WhereTerm *pOrTerm = &pOrWc->a[ii];
      if( pOrTerm->leftCursor==iCur || pOrTerm->eOperator==WO_AND ){
        WhereInfo *pSubWInfo;          /* Info for single OR-term scan */
        /* Loop through table entries that match term pOrTerm. */
        pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrTerm->pExpr, 0,
                        WHERE_OMIT_OPEN | WHERE_OMIT_CLOSE |
                        WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY);
        if( pSubWInfo ){
          if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
            int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
            int r;
            r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, 
                                         regRowid, 0);
            sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset,
                                 sqlite3VdbeCurrentAddr(v)+2, r, iSet);
          }
          sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);

          /* The pSubWInfo->untestedTerms flag means that this OR term
          ** contained one or more AND term from a notReady table.  The
          ** terms from the notReady table could not be tested and will
          ** need to be tested later.
          */
          if( pSubWInfo->untestedTerms ) untestedTerms = 1;

          /* Finish the loop through table entries that match term pOrTerm. */
          sqlite3WhereEnd(pSubWInfo);
        }
      }
    }
    sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));

    sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
    sqlite3VdbeResolveLabel(v, iLoopBody);

    if( pWInfo->nLevel>1 ) sqlite3StackFree(pParse->db, pOrTab);

    if( !untestedTerms ) disableTerm(pLevel, pTerm);
  }else
#endif /* SQLITE_OMIT_OR_OPTIMIZATION */

  {
    /* Case 5:  There is no usable index.  We must do a complete
    **          scan of the entire table.
    */
................................................................................
  */
  k = 0;
  for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
    Expr *pE;
    testcase( pTerm->wtFlags & TERM_VIRTUAL );
    testcase( pTerm->wtFlags & TERM_CODED );
    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
    if( (pTerm->prereqAll & notReady)!=0 ){
      testcase( pWInfo->untestedTerms==0
               && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
      pWInfo->untestedTerms = 1;
      continue;
    }
    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;
    }
    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
    k = 1;
................................................................................
    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
    VdbeComment((v, "record LEFT JOIN hit"));
    sqlite3ExprCacheClear(pParse);
    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
      testcase( pTerm->wtFlags & TERM_VIRTUAL );
      testcase( pTerm->wtFlags & TERM_CODED );
      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
      if( (pTerm->prereqAll & notReady)!=0 ){
        assert( pWInfo->untestedTerms );
        continue;
      }
      assert( pTerm->pExpr );
      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
      pTerm->wtFlags |= TERM_CODED;
    }
  }
  sqlite3ReleaseTempReg(pParse, iReleaseReg);

................................................................................
  SrcList *pTabList,    /* A list of all tables to be scanned */
  Expr *pWhere,         /* The WHERE clause */
  ExprList **ppOrderBy, /* An ORDER BY clause, or NULL */
  u16 wctrlFlags        /* One of the WHERE_* flags defined in sqliteInt.h */
){
  int i;                     /* Loop counter */
  int nByteWInfo;            /* Num. bytes allocated for WhereInfo struct */
  int nTabList;              /* Number of elements in pTabList */
  WhereInfo *pWInfo;         /* Will become the return value of this function */
  Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
  Bitmask notReady;          /* Cursors that are not yet positioned */
  WhereMaskSet *pMaskSet;    /* The expression mask set */
  WhereClause *pWC;               /* Decomposition of the WHERE clause */
  struct SrcList_item *pTabItem;  /* A single entry from pTabList */
  WhereLevel *pLevel;             /* A single level in the pWInfo list */
................................................................................
  /* The number of tables in the FROM clause is limited by the number of
  ** bits in a Bitmask 
  */
  if( pTabList->nSrc>BMS ){
    sqlite3ErrorMsg(pParse, "at most %d tables in a join", BMS);
    return 0;
  }

  /* This function normally generates a nested loop for all tables in 
  ** pTabList.  But if the WHERE_ONETABLE_ONLY flag is set, then we should
  ** only generate code for the first table in pTabList and assume that
  ** any cursors associated with subsequent tables are uninitialized.
  */
  nTabList = (wctrlFlags & WHERE_ONETABLE_ONLY) ? 1 : pTabList->nSrc;

  /* Allocate and initialize the WhereInfo structure that will become the
  ** return value. A single allocation is used to store the WhereInfo
  ** struct, the contents of WhereInfo.a[], the WhereClause structure
  ** and the WhereMaskSet structure. Since WhereClause contains an 8-byte
  ** field (type Bitmask) it must be aligned on an 8-byte boundary on
  ** some architectures. Hence the ROUND8() below.
  */
  db = pParse->db;
  nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
  pWInfo = sqlite3DbMallocZero(db, 
      nByteWInfo + 
      sizeof(WhereClause) +
      sizeof(WhereMaskSet)
  );
  if( db->mallocFailed ){
    goto whereBeginError;
  }
  pWInfo->nLevel = nTabList;
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
  pWInfo->pWC = pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
  pWInfo->wctrlFlags = wctrlFlags;
  pMaskSet = (WhereMaskSet*)&pWC[1];

................................................................................
  whereClauseInit(pWC, pParse, pMaskSet);
  sqlite3ExprCodeConstants(pParse, pWhere);
  whereSplit(pWC, pWhere, TK_AND);
    
  /* Special case: a WHERE clause that is constant.  Evaluate the
  ** expression and either jump over all of the code or fall thru.
  */
  if( pWhere && (nTabList==0 || sqlite3ExprIsConstantNotJoin(pWhere)) ){
    sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, SQLITE_JUMPIFNULL);
    pWhere = 0;
  }

  /* Assign a bit from the bitmask to every term in the FROM clause.
  **
  ** When assigning bitmask values to FROM clause cursors, it must be
................................................................................
  ** bitmask for all tables to the left of the join.  Knowing the bitmask
  ** for all tables to the left of a left join is important.  Ticket #3015.
  **
  ** Configure the WhereClause.vmask variable so that bits that correspond
  ** to virtual table cursors are set. This is used to selectively disable 
  ** the OR-to-IN transformation in exprAnalyzeOrTerm(). It is not helpful 
  ** with virtual tables.
  **
  ** Note that bitmasks are created for all pTabList->nSrc tables in
  ** pTabList, not just the first nTabList tables.  nTabList is normally
  ** equal to pTabList->nSrc but might be shortened to 1 if the
  ** WHERE_ONETABLE_ONLY flag is set.
  */
  assert( pWC->vmask==0 && pMaskSet->n==0 );
  for(i=0; i<pTabList->nSrc; i++){
    createMask(pMaskSet, pTabList->a[i].iCursor);
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( ALWAYS(pTabList->a[i].pTab) && IsVirtual(pTabList->a[i].pTab) ){
      pWC->vmask |= ((Bitmask)1 << i);
................................................................................
  ** clause.
  */
  notReady = ~(Bitmask)0;
  pTabItem = pTabList->a;
  pLevel = pWInfo->a;
  andFlags = ~0;
  WHERETRACE(("*** Optimizer Start ***\n"));
  for(i=iFrom=0, pLevel=pWInfo->a; i<nTabList; i++, pLevel++){
    WhereCost bestPlan;         /* Most efficient plan seen so far */
    Index *pIdx;                /* Index for FROM table at pTabItem */
    int j;                      /* For looping over FROM tables */
    int bestJ = -1;             /* The value of j */
    Bitmask m;                  /* Bitmask value for j or bestJ */
    int isOptimal;              /* Iterator for optimal/non-optimal search */

................................................................................
    ** However, since the cost of a linear scan through table t2 is the same 
    ** as the cost of a linear scan through table t1, a simple greedy 
    ** algorithm may choose to use t2 for the outer loop, which is a much
    ** costlier approach.
    */
    for(isOptimal=1; isOptimal>=0 && bestJ<0; isOptimal--){
      Bitmask mask = (isOptimal ? 0 : notReady);
      assert( (nTabList-iFrom)>1 || isOptimal );
      for(j=iFrom, pTabItem=&pTabList->a[j]; j<nTabList; j++, pTabItem++){
        int doNotReorder;    /* True if this table should not be reordered */
        WhereCost sCost;     /* Cost information from best[Virtual]Index() */
        ExprList *pOrderBy;  /* ORDER BY clause for index to optimize */
  
        doNotReorder =  (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0;
        if( j!=iFrom && doNotReorder ) break;
        m = getMask(pMaskSet, pTabItem->iCursor);
................................................................................
    pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
  }

  /* Open all tables in the pTabList and any indices selected for
  ** searching those tables.
  */
  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
  for(i=0, pLevel=pWInfo->a; i<nTabList; i++, pLevel++){
    Table *pTab;     /* Table to open */
    int iDb;         /* Index of database containing table/index */

#ifndef SQLITE_OMIT_EXPLAIN
    if( pParse->explain==2 ){
      char *zMsg;
      struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
................................................................................
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
  ** program.
  */
  notReady = ~(Bitmask)0;
  for(i=0; i<nTabList; i++){
    notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady);
    pWInfo->iContinue = pWInfo->a[i].addrCont;
  }

#ifdef SQLITE_TEST  /* For testing and debugging use only */
  /* Record in the query plan information about the current table
  ** and the index used to access it (if any).  If the table itself
  ** is not used, its name is just '{}'.  If no index is used
  ** the index is listed as "{}".  If the primary key is used the
  ** index name is '*'.
  */
  for(i=0; i<nTabList; i++){
    char *z;
    int n;
    pLevel = &pWInfo->a[i];
    pTabItem = &pTabList->a[pLevel->iFrom];
    z = pTabItem->zAlias;
    if( z==0 ) z = pTabItem->pTab->zName;
    n = sqlite3Strlen30(z);
................................................................................
  WhereLevel *pLevel;
  SrcList *pTabList = pWInfo->pTabList;
  sqlite3 *db = pParse->db;

  /* Generate loop termination code.
  */
  sqlite3ExprCacheClear(pParse);
  for(i=pWInfo->nLevel-1; i>=0; i--){
    pLevel = &pWInfo->a[i];
    sqlite3VdbeResolveLabel(v, pLevel->addrCont);
    if( pLevel->op!=OP_Noop ){
      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
      sqlite3VdbeChangeP5(v, pLevel->p5);
    }
    if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
................................................................................
  /* The "break" point is here, just past the end of the outer loop.
  ** Set it.
  */
  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);

  /* Close all of the cursors that were opened by sqlite3WhereBegin.
  */
  assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc );
  for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
    Table *pTab = pTabItem->pTab;
    assert( pTab!=0 );
    if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ) continue;
    if( (pWInfo->wctrlFlags & WHERE_OMIT_CLOSE)==0 ){
      if( !pWInfo->okOnePass && (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);

do_test attach-9.3 {
  execsql {
    COMMIT;
    SELECT * FROM aux2.t1;
  }
} {1 2 3 4}






















finish_test

do_test attach-9.3 {
  execsql {
    COMMIT;
    SELECT * FROM aux2.t1;
  }
} {1 2 3 4}

# Ticket [abe728bbc311d81334dae9762f0db87c07a98f79].
# Multi-database commit on an attached TEMP database.
#
do_test attach-10.1 {
  execsql {
    ATTACH '' AS noname;
    ATTACH ':memory:' AS inmem;
    BEGIN;
    CREATE TABLE noname.noname(x);
    CREATE TABLE inmem.inmem(y);
    CREATE TABLE main.main(z);
    COMMIT;
    SELECT name FROM noname.sqlite_master;
    SELECT name FROM inmem.sqlite_master;
  }
} {noname inmem}
do_test attach-10.2 {
  lrange [execsql {
    PRAGMA database_list;
  }] 9 end
} {4 noname {} 5 inmem {}}
finish_test

proc eqp {sql {db db}} { uplevel execsql [list "EXPLAIN QUERY PLAN $sql"] $db }

###########################################################################
### SECTION 2: Enabling Foreign Key Support
###########################################################################

#-------------------------------------------------------------------------
# /* EV: R-33710-56344 */
#
# Test builds neither OMIT_FOREIGN_KEY or OMIT_TRIGGER defined have 
# foreign key functionality.
#
ifcapable trigger&&foreignkey {
  do_test e_fkey-1 {
    execsql {
      PRAGMA foreign_keys = ON;
      CREATE TABLE p(i PRIMARY KEY);
      CREATE TABLE c(j REFERENCES p ON UPDATE CASCADE);
................................................................................
      UPDATE p SET i = 'world';
      SELECT * FROM c;
    }
  } {world}
}

#-------------------------------------------------------------------------
# /* EV: R-44697-61543 */
#
# Test the effects of defining OMIT_TRIGGER but not OMIT_FOREIGN_KEY.
#


# /* EV: R-22567-44039 */
# /* EV: R-41784-13339 */

#
# Specifically, test that "PRAGMA foreign_keys" is a no-op in this case.
# When using the pragma to query the current setting, 0 rows are returned.









#
reset_db
ifcapable !trigger&&foreignkey {
  do_test e_fkey-2.1 {
    execsql {
      PRAGMA foreign_keys = ON;
      CREATE TABLE p(i PRIMARY KEY);
................................................................................
  do_test e_fkey-2.3 {
    execsql { PRAGMA foreign_keys }
  } {}
}


#-------------------------------------------------------------------------
# /* EV: R-58428-36660 */
#
# Test the effects of defining OMIT_FOREIGN_KEY.


#
# /* EV: R-58428-36660 */
#
# Specifically, test that foreign key constraints cannot even be parsed 
# in such a build.
#
reset_db
................................................................................
}

ifcapable !foreignkey||!trigger { finish_test ; return }
reset_db


#-------------------------------------------------------------------------
# /* EV: R-07280-60510 */
#
# Test that even if foreign keys are supported by the build, they must
# be enabled using "PRAGMA foreign_keys = ON" (or similar).
#
# /* EV: R-59578-04990 */

#
# This also tests that foreign key constraints are disabled by default.


#
drop_all_tables
do_test e_fkey-4.1 {
  execsql {
    CREATE TABLE p(i PRIMARY KEY);
    CREATE TABLE c(j REFERENCES p ON UPDATE CASCADE);
    INSERT INTO p VALUES('hello');
................................................................................
    INSERT INTO c VALUES('hello');
    UPDATE p SET i = 'world';
    SELECT * FROM c;
  } 
} {world}

#-------------------------------------------------------------------------
# /* EV: R-15278-54456 */
# /* EV: R-11255-19907 */

#
# Test that the application can use "PRAGMA foreign_keys" to query for
# whether or not foreign keys are currently enabled. This also tests
# the example code in section 2 of foreignkeys.in.
#


reset_db
do_test e_fkey-5.1 {
  execsql { PRAGMA foreign_keys }
} {0}
do_test e_fkey-5.2 {
  execsql { 
    PRAGMA foreign_keys = ON;
................................................................................
  execsql { 
    PRAGMA foreign_keys = OFF;
    PRAGMA foreign_keys;
  }
} {0}

#-------------------------------------------------------------------------
# /* EV: R-46649-58537 */
#
# Test that it is not possible to enable or disable foreign key support
# while not in auto-commit mode.





#
reset_db
do_test e_fkey-6.1 {
  execsql {
    PRAGMA foreign_keys = ON;
    CREATE TABLE t1(a UNIQUE, b);
    CREATE TABLE t2(c, d REFERENCES t1(a));
................................................................................

###########################################################################
### SECTION 1: Introduction to Foreign Key Constraints
###########################################################################
execsql "PRAGMA foreign_keys = ON"

#-------------------------------------------------------------------------
# /* EV: R-04042-24825 */
#
# Verify that the syntax in the first example in section 1 is valid.




#
do_test e_fkey-7.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
      trackartist INTEGER,
      FOREIGN KEY(trackartist) REFERENCES artist(artistid)
    );
  }
} {}

#-------------------------------------------------------------------------
# /* EV: R-61362-32087 */
#
# Attempting to insert a row into the 'track' table that corresponds
# to no row in the 'artist' table fails.
#
do_test e_fkey-8.1 {
  catchsql { INSERT INTO track VALUES(1, 'track 1', 1) }
} {1 {foreign key constraint failed}}
do_test e_fkey-8.2 {
  execsql { INSERT INTO artist VALUES(2, 'artist 1') }
  catchsql { INSERT INTO track VALUES(1, 'track 1', 1) }
} {1 {foreign key constraint failed}}
do_test e_fkey-8.2 {
  execsql { INSERT INTO track VALUES(1, 'track 1', 2) }
} {}

#-------------------------------------------------------------------------
# /* EV: R-24401-52400 */

#
# Attempting to delete a row from the 'artist' table while there are 
# dependent rows in the track table also fails.
#
do_test e_fkey-9.1 {
  catchsql { DELETE FROM artist WHERE artistid = 2 }
} {1 {foreign key constraint failed}}
do_test e_fkey-9.2 {
  execsql { 
    DELETE FROM track WHERE trackartist = 2;
    DELETE FROM artist WHERE artistid = 2;
  }
} {}

#-------------------------------------------------------------------------
# /* EV: R-23980-48859 */
#
# If the foreign key column (trackartist) in table 'track' is set to NULL,
# there is no requirement for a matching row in the 'artist' table.




#
do_test e_fkey-10.1 {
  execsql {
    INSERT INTO track VALUES(1, 'track 1', NULL);
    INSERT INTO track VALUES(2, 'track 2', NULL);
  }
} {}
................................................................................
# /* EV: R-52486-21352 */
#
# Test that the following is true fo all rows in the track table:
#
#   trackartist IS NULL OR 
#   EXISTS(SELECT 1 FROM artist WHERE artistid=trackartist)
#





# This procedure executes a test case to check that statement 
# R-52486-21352 is true after executing the SQL statement passed.
# as the second argument.
proc test_r52486_21352 {tn sql} {
  set res [catchsql $sql]
  set results {
................................................................................

#-------------------------------------------------------------------------
# /* EV: R-42412-59321 */
#
# Check that a NOT NULL constraint can be added to the example schema
# to prohibit NULL child keys from being inserted.
#





drop_all_tables
do_test e_fkey-12.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
  }
} {}
do_test e_fkey-12.2 {
  catchsql { INSERT INTO track VALUES(14, 'Mr. Bojangles', NULL) }
} {1 {track.trackartist may not be NULL}}

#-------------------------------------------------------------------------
# /* EV: R-17902-59250 */
#
# Test an example from foreignkeys.html.
#
drop_all_tables
do_test e_fkey-13.1 {
  execsql {
    CREATE TABLE artist(
................................................................................
    INSERT INTO artist VALUES(3, 'Sammy Davis Jr.');
    UPDATE track SET trackartist = 3 WHERE trackname = 'Mr. Bojangles';
    INSERT INTO track VALUES(15, 'Boogie Woogie', 3);
  }
} {}

#-------------------------------------------------------------------------
# /* EV: R-15034-64331 */
#
# Test the second example from the first section of foreignkeys.html.
#
do_test e_fkey-14.1 {
  catchsql {
    DELETE FROM artist WHERE artistname = 'Frank Sinatra';
  }
................................................................................
    DELETE FROM track WHERE trackname IN('That''s Amore', 'Christmas Blues');
    UPDATE artist SET artistid=4 WHERE artistname = 'Dean Martin';
  }
} {}


#-------------------------------------------------------------------------
# /* EV: R-56032-24923 */
#
# Test that a foreign key constraint is satisifed if "for each row in the child
# table either one or more of the child key columns are NULL, or there exists a
# row in the parent table for which each parent key column contains a value
# equal to the value in its associated child key column".
#
# /* EV: R-57765-12380 */
#
# Test also that the comparison rules are used when testing if there 
# is a matching row in the parent table of a foreign key constraint.
#
drop_all_tables
do_test e_fkey-15.1 {
  execsql {
    CREATE TABLE par(p PRIMARY KEY);
    CREATE TABLE chi(c REFERENCES par);

    INSERT INTO par VALUES(1);
................................................................................
test_efkey_45 5 0 "DELETE FROM chi WHERE c = '1'"
test_efkey_45 6 0 "DELETE FROM par WHERE p = '1'"
test_efkey_45 7 1 "INSERT INTO chi VALUES('1')"
test_efkey_45 8 0 "INSERT INTO chi VALUES(X'31')"
test_efkey_45 9 1 "INSERT INTO chi VALUES(X'32')"

#-------------------------------------------------------------------------
# /* EV: R-15796-47513 */
#
# Specifically, test that when comparing child and parent key values the
# default collation sequence of the parent key column is used.



#
drop_all_tables
do_test e_fkey-16.1 {
  execsql {
    CREATE TABLE t1(a COLLATE nocase PRIMARY KEY);
    CREATE TABLE t2(b REFERENCES t1);
  }
................................................................................
  catchsql { UPDATE t2 SET b = 'two' WHERE rowid = 1 }
} {1 {foreign key constraint failed}}
do_test e_fkey-16.4 {
  catchsql { DELETE FROM t1 WHERE rowid = 1 }
} {1 {foreign key constraint failed}}

#-------------------------------------------------------------------------
# /* EV: R-04240-13860 */
#
# Specifically, test that when comparing child and parent key values the
# affinity of the parent key column is applied to the child key value
# before the comparison takes place.




#
drop_all_tables
do_test e_fkey-17.1 {
  execsql {
    CREATE TABLE t1(a NUMERIC PRIMARY KEY);
    CREATE TABLE t2(b TEXT REFERENCES t1);
  }
................................................................................
} {1 {foreign key constraint failed}}

###########################################################################
### SECTION 3: Required and Suggested Database Indexes
###########################################################################

#-------------------------------------------------------------------------
# /* EV: R-13435-26311 */
#
# A parent key must be either a PRIMARY KEY, subject to a UNIQUE 
# constraint, or have a UNIQUE index created on it.
# 


# /* EV: R-00376-39212 */

#
# Also test that if a parent key is not subject to a PRIMARY KEY or UNIQUE
# constraint, but does have a UNIQUE index created on it, then the UNIQUE index
# must use the default collation sequences associated with the parent key
# columns.




#
drop_all_tables
do_test e_fkey-18.1 {
  execsql {
    CREATE TABLE t2(a REFERENCES t1(x));
  }
} {}
................................................................................
}


#-------------------------------------------------------------------------
# This block tests an example in foreignkeys.html. Several testable
# statements refer to this example, as follows
#
# /* EV: R-27484-01467 */
#
# FK Constraints on child1, child2 and child3 are Ok.
#
# /* EV: R-51039-44840 */
#
# Problem with FK on child4.
#


# /* EV: R-01060-48788 */
#
# Problem with FK on child5.
#
# /* EV: R-63088-37469 */


#
# Problem with FK on child6 and child7.




#
drop_all_tables
do_test e_fkey-19.1 {
  execsql {
    CREATE TABLE parent(a PRIMARY KEY, b UNIQUE, c, d, e, f);
    CREATE UNIQUE INDEX i1 ON parent(c, d);
    CREATE INDEX i2 ON parent(e);
................................................................................
  catchsql { INSERT INTO child6 VALUES(2, 3) }
} {1 {foreign key mismatch}}
do_test e_fkey-19.5 {
  catchsql { INSERT INTO child7 VALUES(3) }
} {1 {foreign key mismatch}}

#-------------------------------------------------------------------------
# /* EV: R-45488-08504 */
# /* EV: R-48391-38472 */
# /* EV: R-03108-63659 */
# /* EV: R-60781-26576 */
#
# Test errors in the database schema that are detected while preparing
# DML statements. The error text for these messages always matches 
# either "foreign key mismatch" or "no such table*" (using [string match]).























#
do_test e_fkey-20.1 {
  execsql {
    CREATE TABLE c1(c REFERENCES nosuchtable, d);

    CREATE TABLE p2(a, b, UNIQUE(a, b));
    CREATE TABLE c2(c, d, FOREIGN KEY(c, d) REFERENCES p2(a, x));
................................................................................
    do_test e_fkey-20.$tn.6 {
      catchsql "INSERT INTO $ptbl SELECT ?, ?"
    } [list 1 $err]
  }
}

#-------------------------------------------------------------------------
# /* EV: R-19353-43643 */
#
# Test the example of foreign key mismatch errors caused by implicitly
# mapping a child key to the primary key of the parent table when the
# child key consists of a different number of columns to that primary key.
# 
drop_all_tables
do_test e_fkey-21.1 {
................................................................................
  catchsql { INSERT INTO child10 VALUES(1, 2, 3) }
} {1 {foreign key mismatch}}
do_test e_fkey-21.8 {
  catchsql { INSERT INTO child10 VALUES(NULL, NULL, NULL) }
} {1 {foreign key mismatch}}

#-------------------------------------------------------------------------
# /* EV: R-23682-59820 */
#
# Test errors that are reported when creating the child table. 
# Specifically:
#
#   * different number of child and parent key columns, and
#   * child columns that do not exist.
#
# /* EV: R-33883-28833 */



#
# These errors are reported whether or not FK support is enabled.




#
drop_all_tables
foreach fk [list OFF ON] {
  execsql "PRAGMA foreign_keys = $fk"
  set i 0
  foreach {sql error} {
    "CREATE TABLE child1(a, b, FOREIGN KEY(a, b) REFERENCES p(c))"
................................................................................
test_efkey_60 3 0 "INSERT INTO p1 VALUES(239, 231)"
test_efkey_60 4 0 "INSERT INTO c1 VALUES(239, 231)"
test_efkey_60 5 1 "INSERT INTO c2 VALUES(239, 231)"
test_efkey_60 6 0 "INSERT INTO p2 VALUES(239, 231)"
test_efkey_60 7 0 "INSERT INTO c2 VALUES(239, 231)"

#-------------------------------------------------------------------------
# /* EV: R-15417-28014 */
#
# Test that an index on on the child key columns of an FK constraint
# is optional.



#
# /* EV: R-15741-50893 */
#
# Also test that if an index is created on the child key columns, it does
# not make a difference whether or not it is a UNIQUE index.
#
drop_all_tables
................................................................................
  test_efkey_61 $tn.2 0 "INSERT INTO parent VALUES(1, 2)"
  test_efkey_61 $tn.3 0 "INSERT INTO $c VALUES(1, 2)"

  execsql "DELETE FROM $c ; DELETE FROM parent"
}

#-------------------------------------------------------------------------
# /* EV: R-00279-52283 */
#
# Test an example showing that when a row is deleted from the parent 
# table, the child table is queried for orphaned rows as follows:
#
#   SELECT rowid FROM track WHERE trackartist = ?
#
# /* EV: R-23302-30956 */
#
# Also test that if the SELECT above would return any rows, a foreign
# key constraint is violated.
#
do_test e_fkey-25.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
do_test e_fkey-25.7 {
  concat \
    [execsql { SELECT rowid FROM track WHERE trackartist = 6 }]   \
    [catchsql { DELETE FROM artist WHERE artistid = 6 }]
} {2 1 {foreign key constraint failed}}

#-------------------------------------------------------------------------
# /* EV: R-54172-55848 */
#
# Test that when a row is deleted from the parent table of an FK 
# constraint, the child table is queried for orphaned rows. The
# query is equivalent to:
#
#   SELECT rowid FROM <child-table> WHERE <child-key> = :parent_key_value
#
................................................................................
#
# Also test that when a row is inserted into the parent table, or when the 
# parent key values of an existing row are modified, a query equivalent
# to the following is planned. In some cases it is not executed, but it
# is always planned.
#
#   SELECT rowid FROM <child-table> WHERE <child-key> = :parent_key_value




#
#
drop_all_tables
do_test e_fkey-26.1 {
  execsql { CREATE TABLE parent(x, y, UNIQUE(y, x)) }
} {}
foreach {tn sql} {

proc eqp {sql {db db}} { uplevel execsql [list "EXPLAIN QUERY PLAN $sql"] $db }

###########################################################################
### SECTION 2: Enabling Foreign Key Support
###########################################################################

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-33710-56344 In order to use foreign key constraints in
# SQLite, the library must be compiled with neither
# SQLITE_OMIT_FOREIGN_KEY or SQLITE_OMIT_TRIGGER defined.

#
ifcapable trigger&&foreignkey {
  do_test e_fkey-1 {
    execsql {
      PRAGMA foreign_keys = ON;
      CREATE TABLE p(i PRIMARY KEY);
      CREATE TABLE c(j REFERENCES p ON UPDATE CASCADE);
................................................................................
      UPDATE p SET i = 'world';
      SELECT * FROM c;
    }
  } {world}
}

#-------------------------------------------------------------------------


# Test the effects of defining OMIT_TRIGGER but not OMIT_FOREIGN_KEY.
#
# EVIDENCE-OF: R-44697-61543 If SQLITE_OMIT_TRIGGER is defined but
# SQLITE_OMIT_FOREIGN_KEY is not, then SQLite behaves as it did prior to
# version 3.6.19 - foreign key definitions are parsed and may be queried
# using PRAGMA foreign_key_list, but foreign key constraints are not
# enforced.
#
# Specifically, test that "PRAGMA foreign_keys" is a no-op in this case.
# When using the pragma to query the current setting, 0 rows are returned.
#
# EVIDENCE-OF: R-22567-44039 The PRAGMA foreign_keys command is a no-op
# in this configuration.
#
# EVIDENCE-OF: R-41784-13339 Tip: If the command "PRAGMA foreign_keys"
# returns no data instead of a single row containing "0" or "1", then
# the version of SQLite you are using does not support foreign keys
# (either because it is older than 3.6.19 or because it was compiled
# with SQLITE_OMIT_FOREIGN_KEY or SQLITE_OMIT_TRIGGER defined).
#
reset_db
ifcapable !trigger&&foreignkey {
  do_test e_fkey-2.1 {
    execsql {
      PRAGMA foreign_keys = ON;
      CREATE TABLE p(i PRIMARY KEY);
................................................................................
  do_test e_fkey-2.3 {
    execsql { PRAGMA foreign_keys }
  } {}
}


#-------------------------------------------------------------------------
# Test the effects of defining OMIT_FOREIGN_KEY.
#
# EVIDENCE-OF: R-58428-36660 If OMIT_FOREIGN_KEY is defined, then
# foreign key definitions cannot even be parsed (attempting to specify a
# foreign key definition is a syntax error).
#
# /* EV: R-58428-36660 */
#
# Specifically, test that foreign key constraints cannot even be parsed 
# in such a build.
#
reset_db
................................................................................
}

ifcapable !foreignkey||!trigger { finish_test ; return }
reset_db


#-------------------------------------------------------------------------
# EVIDENCE-OF: R-07280-60510 Assuming the library is compiled with
# foreign key constraints enabled, it must still be enabled by the
# application at runtime, using the PRAGMA foreign_keys command.

#

# This also tests that foreign key constraints are disabled by default.
#
# EVIDENCE-OF: R-59578-04990 Foreign key constraints are disabled by
# default (for backwards compatibility), so must be enabled separately
# for each database connection separately.
#
drop_all_tables
do_test e_fkey-4.1 {
  execsql {
    CREATE TABLE p(i PRIMARY KEY);
    CREATE TABLE c(j REFERENCES p ON UPDATE CASCADE);
    INSERT INTO p VALUES('hello');
................................................................................
    INSERT INTO c VALUES('hello');
    UPDATE p SET i = 'world';
    SELECT * FROM c;
  } 
} {world}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-15278-54456 The application can can also use a PRAGMA
# foreign_keys statement to determine if foreign keys are currently
# enabled.
#


# This also tests the example code in section 2 of foreignkeys.in.
#
# EVIDENCE-OF: R-11255-19907
# 
reset_db
do_test e_fkey-5.1 {
  execsql { PRAGMA foreign_keys }
} {0}
do_test e_fkey-5.2 {
  execsql { 
    PRAGMA foreign_keys = ON;
................................................................................
  execsql { 
    PRAGMA foreign_keys = OFF;
    PRAGMA foreign_keys;
  }
} {0}

#-------------------------------------------------------------------------


# Test that it is not possible to enable or disable foreign key support
# while not in auto-commit mode.
#
# EVIDENCE-OF: R-46649-58537 It is not possible to enable or disable
# foreign key constraints in the middle of a multi-statement transaction
# (when SQLite is not in autocommit mode). Attempting to do so does not
# return an error; it simply has no effect.
#
reset_db
do_test e_fkey-6.1 {
  execsql {
    PRAGMA foreign_keys = ON;
    CREATE TABLE t1(a UNIQUE, b);
    CREATE TABLE t2(c, d REFERENCES t1(a));
................................................................................

###########################################################################
### SECTION 1: Introduction to Foreign Key Constraints
###########################################################################
execsql "PRAGMA foreign_keys = ON"

#-------------------------------------------------------------------------
# Verify that the syntax in the first example in section 1 is valid.
#
# EVIDENCE-OF: R-04042-24825 To do so, a foreign key definition may be
# added by modifying the declaration of the track table to the
# following: CREATE TABLE track( trackid INTEGER, trackname TEXT,
# trackartist INTEGER, FOREIGN KEY(trackartist) REFERENCES
# artist(artistid) );
#
do_test e_fkey-7.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
      trackartist INTEGER,
      FOREIGN KEY(trackartist) REFERENCES artist(artistid)
    );
  }
} {}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-61362-32087 Attempting to insert a row into the track
# table that does not correspond to any row in the artist table will
# fail,

#
do_test e_fkey-8.1 {
  catchsql { INSERT INTO track VALUES(1, 'track 1', 1) }
} {1 {foreign key constraint failed}}
do_test e_fkey-8.2 {
  execsql { INSERT INTO artist VALUES(2, 'artist 1') }
  catchsql { INSERT INTO track VALUES(1, 'track 1', 1) }
} {1 {foreign key constraint failed}}
do_test e_fkey-8.2 {
  execsql { INSERT INTO track VALUES(1, 'track 1', 2) }
} {}

#-------------------------------------------------------------------------
# Attempting to delete a row from the 'artist' table while there are 
# dependent rows in the track table also fails.
#
# EVIDENCE-OF: R-24401-52400 as will attempting to delete a row from the
# artist table when there exist dependent rows in the track table
#
do_test e_fkey-9.1 {
  catchsql { DELETE FROM artist WHERE artistid = 2 }
} {1 {foreign key constraint failed}}
do_test e_fkey-9.2 {
  execsql { 
    DELETE FROM track WHERE trackartist = 2;
    DELETE FROM artist WHERE artistid = 2;
  }
} {}

#-------------------------------------------------------------------------


# If the foreign key column (trackartist) in table 'track' is set to NULL,
# there is no requirement for a matching row in the 'artist' table.
#
# EVIDENCE-OF: R-23980-48859 There is one exception: if the foreign key
# column in the track table is NULL, then no corresponding entry in the
# artist table is required.
#
do_test e_fkey-10.1 {
  execsql {
    INSERT INTO track VALUES(1, 'track 1', NULL);
    INSERT INTO track VALUES(2, 'track 2', NULL);
  }
} {}
................................................................................
# /* EV: R-52486-21352 */
#
# Test that the following is true fo all rows in the track table:
#
#   trackartist IS NULL OR 
#   EXISTS(SELECT 1 FROM artist WHERE artistid=trackartist)
#
# EVIDENCE-OF: R-52486-21352 Expressed in SQL, this means that for every
# row in the track table, the following expression evaluates to true:
# trackartist IS NULL OR EXISTS(SELECT 1 FROM artist WHERE
# artistid=trackartist)

# This procedure executes a test case to check that statement 
# R-52486-21352 is true after executing the SQL statement passed.
# as the second argument.
proc test_r52486_21352 {tn sql} {
  set res [catchsql $sql]
  set results {
................................................................................

#-------------------------------------------------------------------------
# /* EV: R-42412-59321 */
#
# Check that a NOT NULL constraint can be added to the example schema
# to prohibit NULL child keys from being inserted.
#
# EVIDENCE-OF: R-42412-59321 Tip: If the application requires a stricter
# relationship between artist and track, where NULL values are not
# permitted in the trackartist column, simply add the appropriate "NOT
# NULL" constraint to the schema.
#
drop_all_tables
do_test e_fkey-12.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
  }
} {}
do_test e_fkey-12.2 {
  catchsql { INSERT INTO track VALUES(14, 'Mr. Bojangles', NULL) }
} {1 {track.trackartist may not be NULL}}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-17902-59250
#
# Test an example from foreignkeys.html.
#
drop_all_tables
do_test e_fkey-13.1 {
  execsql {
    CREATE TABLE artist(
................................................................................
    INSERT INTO artist VALUES(3, 'Sammy Davis Jr.');
    UPDATE track SET trackartist = 3 WHERE trackname = 'Mr. Bojangles';
    INSERT INTO track VALUES(15, 'Boogie Woogie', 3);
  }
} {}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-15034-64331
#
# Test the second example from the first section of foreignkeys.html.
#
do_test e_fkey-14.1 {
  catchsql {
    DELETE FROM artist WHERE artistname = 'Frank Sinatra';
  }
................................................................................
    DELETE FROM track WHERE trackname IN('That''s Amore', 'Christmas Blues');
    UPDATE artist SET artistid=4 WHERE artistname = 'Dean Martin';
  }
} {}


#-------------------------------------------------------------------------
# EVIDENCE-OF: R-56032-24923 The foreign key constraint is satisfied if
# for each row in the child table either one or more of the child key
# columns are NULL, or there exists a row in the parent table for which
# each parent key column contains a value equal to the value in its
# associated child key column.
#
# Test also that the usual comparison rules are used when testing if there 
# is a matching row in the parent table of a foreign key constraint.
#
# EVIDENCE-OF: R-57765-12380 In the above paragraph, the term "equal"
# means equal when values are compared using the rules specified here.
#
drop_all_tables
do_test e_fkey-15.1 {
  execsql {
    CREATE TABLE par(p PRIMARY KEY);
    CREATE TABLE chi(c REFERENCES par);

    INSERT INTO par VALUES(1);
................................................................................
test_efkey_45 5 0 "DELETE FROM chi WHERE c = '1'"
test_efkey_45 6 0 "DELETE FROM par WHERE p = '1'"
test_efkey_45 7 1 "INSERT INTO chi VALUES('1')"
test_efkey_45 8 0 "INSERT INTO chi VALUES(X'31')"
test_efkey_45 9 1 "INSERT INTO chi VALUES(X'32')"

#-------------------------------------------------------------------------


# Specifically, test that when comparing child and parent key values the
# default collation sequence of the parent key column is used.
#
# EVIDENCE-OF: R-15796-47513 When comparing text values, the collating
# sequence associated with the parent key column is always used.
#
drop_all_tables
do_test e_fkey-16.1 {
  execsql {
    CREATE TABLE t1(a COLLATE nocase PRIMARY KEY);
    CREATE TABLE t2(b REFERENCES t1);
  }
................................................................................
  catchsql { UPDATE t2 SET b = 'two' WHERE rowid = 1 }
} {1 {foreign key constraint failed}}
do_test e_fkey-16.4 {
  catchsql { DELETE FROM t1 WHERE rowid = 1 }
} {1 {foreign key constraint failed}}

#-------------------------------------------------------------------------


# Specifically, test that when comparing child and parent key values the
# affinity of the parent key column is applied to the child key value
# before the comparison takes place.
#
# EVIDENCE-OF: R-04240-13860 When comparing values, if the parent key
# column has an affinity, then that affinity is applied to the child key
# value before the comparison is performed.
#
drop_all_tables
do_test e_fkey-17.1 {
  execsql {
    CREATE TABLE t1(a NUMERIC PRIMARY KEY);
    CREATE TABLE t2(b TEXT REFERENCES t1);
  }
................................................................................
} {1 {foreign key constraint failed}}

###########################################################################
### SECTION 3: Required and Suggested Database Indexes
###########################################################################

#-------------------------------------------------------------------------


# A parent key must be either a PRIMARY KEY, subject to a UNIQUE 
# constraint, or have a UNIQUE index created on it.
#
# EVIDENCE-OF: R-13435-26311 Usually, the parent key of a foreign key
# constraint is the primary key of the parent table. If they are not the
# primary key, then the parent key columns must be collectively subject
# to a UNIQUE constraint or have a UNIQUE index.
# 
# Also test that if a parent key is not subject to a PRIMARY KEY or UNIQUE
# constraint, but does have a UNIQUE index created on it, then the UNIQUE index
# must use the default collation sequences associated with the parent key
# columns.
#
# EVIDENCE-OF: R-00376-39212 If the parent key columns have a UNIQUE
# index, then that index must use the collation sequences that are
# specified in the CREATE TABLE statement for the parent table.
#
drop_all_tables
do_test e_fkey-18.1 {
  execsql {
    CREATE TABLE t2(a REFERENCES t1(x));
  }
} {}
................................................................................
}


#-------------------------------------------------------------------------
# This block tests an example in foreignkeys.html. Several testable
# statements refer to this example, as follows
#
# EVIDENCE-OF: R-27484-01467
#
# FK Constraints on child1, child2 and child3 are Ok.
#


# Problem with FK on child4:
#
# EVIDENCE-OF: R-51039-44840 The foreign key declared as part of table
# child4 is an error because even though the parent key column is
# indexed, the index is not UNIQUE.
#
# Problem with FK on child5:
#
# EVIDENCE-OF: R-01060-48788 The foreign key for table child5 is an
# error because even though the parent key column has a unique index,
# the index uses a different collating sequence.
#
# Problem with FK on child6 and child7:
#
# EVIDENCE-OF: R-63088-37469 Tables child6 and child7 are incorrect
# because while both have UNIQUE indices on their parent keys, the keys
# are not an exact match to the columns of a single UNIQUE index.
#
drop_all_tables
do_test e_fkey-19.1 {
  execsql {
    CREATE TABLE parent(a PRIMARY KEY, b UNIQUE, c, d, e, f);
    CREATE UNIQUE INDEX i1 ON parent(c, d);
    CREATE INDEX i2 ON parent(e);
................................................................................
  catchsql { INSERT INTO child6 VALUES(2, 3) }
} {1 {foreign key mismatch}}
do_test e_fkey-19.5 {
  catchsql { INSERT INTO child7 VALUES(3) }
} {1 {foreign key mismatch}}

#-------------------------------------------------------------------------





# Test errors in the database schema that are detected while preparing
# DML statements. The error text for these messages always matches 
# either "foreign key mismatch" or "no such table*" (using [string match]).
#
# EVIDENCE-OF: R-45488-08504 If the database schema contains foreign key
# errors that require looking at more than one table definition to
# identify, then those errors are not detected when the tables are
# created.
#
# EVIDENCE-OF: R-48391-38472 Instead, such errors prevent the
# application from preparing SQL statements that modify the content of
# the child or parent tables in ways that use the foreign keys.
#
# EVIDENCE-OF: R-03108-63659 The English language error message for
# foreign key DML errors is usually "foreign key mismatch" but can also
# be "no such table" if the parent table does not exist.
#
# EVIDENCE-OF: R-60781-26576 Foreign key DML errors are may be reported
# if: The parent table does not exist, or The parent key columns named
# in the foreign key constraint do not exist, or The parent key columns
# named in the foreign key constraint are not the primary key of the
# parent table and are not subject to a unique constraint using
# collating sequence specified in the CREATE TABLE, or The child table
# references the primary key of the parent without specifying the
# primary key columns and the number of primary key columns in the
# parent do not match the number of child key columns.
#
do_test e_fkey-20.1 {
  execsql {
    CREATE TABLE c1(c REFERENCES nosuchtable, d);

    CREATE TABLE p2(a, b, UNIQUE(a, b));
    CREATE TABLE c2(c, d, FOREIGN KEY(c, d) REFERENCES p2(a, x));
................................................................................
    do_test e_fkey-20.$tn.6 {
      catchsql "INSERT INTO $ptbl SELECT ?, ?"
    } [list 1 $err]
  }
}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-19353-43643
#
# Test the example of foreign key mismatch errors caused by implicitly
# mapping a child key to the primary key of the parent table when the
# child key consists of a different number of columns to that primary key.
# 
drop_all_tables
do_test e_fkey-21.1 {
................................................................................
  catchsql { INSERT INTO child10 VALUES(1, 2, 3) }
} {1 {foreign key mismatch}}
do_test e_fkey-21.8 {
  catchsql { INSERT INTO child10 VALUES(NULL, NULL, NULL) }
} {1 {foreign key mismatch}}

#-------------------------------------------------------------------------


# Test errors that are reported when creating the child table. 
# Specifically:
#
#   * different number of child and parent key columns, and
#   * child columns that do not exist.
#
# EVIDENCE-OF: R-23682-59820 By contrast, if foreign key errors can be
# recognized simply by looking at the definition of the child table and
# without having to consult the parent table definition, then the CREATE
# TABLE statement for the child table fails.
#
# These errors are reported whether or not FK support is enabled.
#
# EVIDENCE-OF: R-33883-28833 Foreign key DDL errors are reported
# regardless of whether or not foreign key constraints are enabled when
# the table is created.
#
drop_all_tables
foreach fk [list OFF ON] {
  execsql "PRAGMA foreign_keys = $fk"
  set i 0
  foreach {sql error} {
    "CREATE TABLE child1(a, b, FOREIGN KEY(a, b) REFERENCES p(c))"
................................................................................
test_efkey_60 3 0 "INSERT INTO p1 VALUES(239, 231)"
test_efkey_60 4 0 "INSERT INTO c1 VALUES(239, 231)"
test_efkey_60 5 1 "INSERT INTO c2 VALUES(239, 231)"
test_efkey_60 6 0 "INSERT INTO p2 VALUES(239, 231)"
test_efkey_60 7 0 "INSERT INTO c2 VALUES(239, 231)"

#-------------------------------------------------------------------------


# Test that an index on on the child key columns of an FK constraint
# is optional.
#
# EVIDENCE-OF: R-15417-28014 Indices are not required for child key
# columns
#
# /* EV: R-15741-50893 */
#
# Also test that if an index is created on the child key columns, it does
# not make a difference whether or not it is a UNIQUE index.
#
drop_all_tables
................................................................................
  test_efkey_61 $tn.2 0 "INSERT INTO parent VALUES(1, 2)"
  test_efkey_61 $tn.3 0 "INSERT INTO $c VALUES(1, 2)"

  execsql "DELETE FROM $c ; DELETE FROM parent"
}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-00279-52283
#
# Test an example showing that when a row is deleted from the parent 
# table, the child table is queried for orphaned rows as follows:
#
#   SELECT rowid FROM track WHERE trackartist = ?
#
# EVIDENCE-OF: R-23302-30956 If this SELECT returns any rows at all,
# then SQLite concludes that deleting the row from the parent table
# would violate the foreign key constraint and returns an error.

#
do_test e_fkey-25.1 {
  execsql {
    CREATE TABLE artist(
      artistid    INTEGER PRIMARY KEY, 
      artistname  TEXT
    );
................................................................................
do_test e_fkey-25.7 {
  concat \
    [execsql { SELECT rowid FROM track WHERE trackartist = 6 }]   \
    [catchsql { DELETE FROM artist WHERE artistid = 6 }]
} {2 1 {foreign key constraint failed}}

#-------------------------------------------------------------------------
# EVIDENCE-OF: R-54172-55848
#
# Test that when a row is deleted from the parent table of an FK 
# constraint, the child table is queried for orphaned rows. The
# query is equivalent to:
#
#   SELECT rowid FROM <child-table> WHERE <child-key> = :parent_key_value
#
................................................................................
#
# Also test that when a row is inserted into the parent table, or when the 
# parent key values of an existing row are modified, a query equivalent
# to the following is planned. In some cases it is not executed, but it
# is always planned.
#
#   SELECT rowid FROM <child-table> WHERE <child-key> = :parent_key_value
#
# EVIDENCE-OF: R-61616-46700 Similar queries may be run if the content
# of the parent key is modified or a new row is inserted into the parent
# table.
#
#
drop_all_tables
do_test e_fkey-26.1 {
  execsql { CREATE TABLE parent(x, y, UNIQUE(y, x)) }
} {}
foreach {tn sql} {

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build does not include FTS3, skip the tests in this file.
#
ifcapable !fts3 { finish_test ; return }
source $testdir/fts3_common.tcl


# Procs used to make the tests in this file easier to read.
#
proc ddl_test {tn ddl} {
  uplevel [list do_write_test e_fts3-$tn sqlite_master $ddl]
}
proc write_test {tn tbl sql} {
................................................................................
# that the example code in fts3.html works as expected. The tests run three
# times, with different values for DO_MALLOC_TEST.
# 
#   DO_MALLOC_TEST=0: Run tests with no OOM errors.
#   DO_MALLOC_TEST=1: Run tests with transient OOM errors.
#   DO_MALLOC_TEST=2: Run tests with persistent OOM errors.
#
foreach DO_MALLOC_TEST [lrange {0 1 2} 0 end] {








# Reset the database and database connection. If this iteration of the 
# [foreach] loop is testing with OOM errors, disable the lookaside buffer.
#
db close
file delete -force test.db test.db-journal
sqlite3 db test.db
if {$DO_MALLOC_TEST} { sqlite3_db_config_lookaside db 0 0 0 }


##########################################################################
# Test the example CREATE VIRTUAL TABLE statements in section 1.1 
# of fts3.in.
#
ddl_test   1.1.1.1 {CREATE VIRTUAL TABLE data USING fts3()}
read_test  1.1.1.2 {PRAGMA table_info(data)} {0 content {} 0 {} 0}
................................................................................
  INSERT INTO docs VALUES('"which is for Solomon," meaning that');
}
write_test 1.2.2.4 docs_content {
  INSERT INTO docs VALUES('the book is dedicated to Solomon.');
}
read_test  1.2.2.5 { SELECT count(*) FROM docs_segdir } {3}
write_test 1.2.2.6 docs_segdir {
  SELECT * FROM (SELECT optimize(docs) FROM docs LIMIT 1) WHERE 0;
}
read_test  1.2.2.7 { SELECT count(*) FROM docs_segdir } {1}
ddl_test   1.2.2.8 { DROP TABLE docs }

##########################################################################
# Test the examples in section 1.3 (querying FTS3 tables)
#
................................................................................
} {illegal first argument to snippet}
error_test 2.1.7 {
  SELECT snippet() FROM t1 WHERE a MATCH 'one'
} {unable to use function snippet in the requested context}
error_test 2.1.8 {
  SELECT snippet(a, b, 'A', 'B', 'C') FROM t1 WHERE a MATCH 'one'
} {wrong number of arguments to function snippet()}










































































































































































































finish_test

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build does not include FTS3, skip the tests in this file.
#
ifcapable !fts3 { finish_test ; return }
source $testdir/fts3_common.tcl
source $testdir/malloc_common.tcl

# Procs used to make the tests in this file easier to read.
#
proc ddl_test {tn ddl} {
  uplevel [list do_write_test e_fts3-$tn sqlite_master $ddl]
}
proc write_test {tn tbl sql} {
................................................................................
# that the example code in fts3.html works as expected. The tests run three
# times, with different values for DO_MALLOC_TEST.
# 
#   DO_MALLOC_TEST=0: Run tests with no OOM errors.
#   DO_MALLOC_TEST=1: Run tests with transient OOM errors.
#   DO_MALLOC_TEST=2: Run tests with persistent OOM errors.
#
foreach {DO_MALLOC_TEST enc} {
  0 utf-8
  1 utf-8
  2 utf-8
  1 utf-16
} {

#if {$DO_MALLOC_TEST} break

# Reset the database and database connection. If this iteration of the 
# [foreach] loop is testing with OOM errors, disable the lookaside buffer.
#
db close
file delete -force test.db test.db-journal
sqlite3 db test.db
if {$DO_MALLOC_TEST} { sqlite3_db_config_lookaside db 0 0 0 }
db eval "PRAGMA encoding = '$enc'"

##########################################################################
# Test the example CREATE VIRTUAL TABLE statements in section 1.1 
# of fts3.in.
#
ddl_test   1.1.1.1 {CREATE VIRTUAL TABLE data USING fts3()}
read_test  1.1.1.2 {PRAGMA table_info(data)} {0 content {} 0 {} 0}
................................................................................
  INSERT INTO docs VALUES('"which is for Solomon," meaning that');
}
write_test 1.2.2.4 docs_content {
  INSERT INTO docs VALUES('the book is dedicated to Solomon.');
}
read_test  1.2.2.5 { SELECT count(*) FROM docs_segdir } {3}
write_test 1.2.2.6 docs_segdir {
  INSERT INTO docs(docs) VALUES('optimize');
}
read_test  1.2.2.7 { SELECT count(*) FROM docs_segdir } {1}
ddl_test   1.2.2.8 { DROP TABLE docs }

##########################################################################
# Test the examples in section 1.3 (querying FTS3 tables)
#
................................................................................
} {illegal first argument to snippet}
error_test 2.1.7 {
  SELECT snippet() FROM t1 WHERE a MATCH 'one'
} {unable to use function snippet in the requested context}
error_test 2.1.8 {
  SELECT snippet(a, b, 'A', 'B', 'C') FROM t1 WHERE a MATCH 'one'
} {wrong number of arguments to function snippet()}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test the effect of an OOM error while installing the FTS3 module (i.e.
# opening a database handle). This case was not tested by the OOM testing
# of the document examples above.
#
do_malloc_test e_fts3-3 -tclbody { 
  if {[catch {sqlite3 db test.db}]} { error "out of memory" }
}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Verify the return values of the optimize() function. If no error occurs,
# the returned value should be "Index optimized" if the data structure
# was modified, or "Index already optimal" if it were not.
#
set DO_MALLOC_TEST 0
ddl_test   4.1 { CREATE VIRTUAL TABLE t4 USING fts3(a, b) }
write_test 4.2 t4_content {
  INSERT INTO t4 VALUES('In Xanadu', 'did Kubla Khan');
}
write_test 4.3 t4_content {
  INSERT INTO t4 VALUES('a stately pleasure', 'dome decree');
}
do_test e_fts3-4.4 {
  execsql { SELECT optimize(t4) FROM t4 LIMIT 1 } 
} {{Index optimized}}
do_test e_fts3-4.5 {
  execsql { SELECT optimize(t4) FROM t4 LIMIT 1 } 
} {{Index already optimal}}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test that the snippet function appears to work correctly with 1, 2, 3
# or 4 arguments passed to it.
#
set DO_MALLOC_TEST 0
ddl_test   5.1 { CREATE VIRTUAL TABLE t5 USING fts3(x) }
write_test 5.2 t5_content {
  INSERT INTO t5 VALUES('In Xanadu did Kubla Khan A stately pleasure-dome decree Where Alph, the sacred river, ran Through caverns measureless to man Down to a sunless sea.  So twice five miles of fertile ground With walls and towers were girdled round : And there were gardens bright with sinuous rills, Where blossomed many an incense-bearing tree ; And here were forests ancient as the hills, Enfolding sunny spots of greenery.');
}
read_test 5.3 { 
  SELECT snippet(t5) FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b> Down to a sunless sea.  So twice five <b>miles</b> of fertile ground With walls and towers were <b>...</b>}}
read_test 5.4 { 
  SELECT snippet(t5, '<i>') FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b> Down to a sunless sea.  So twice five <i>miles</b> of fertile ground With walls and towers were <b>...</b>}}
read_test 5.5 { 
  SELECT snippet(t5, '<i>', '</i>') FROM t5 WHERE t5 MATCH 'miles'
} {{<b>...</b> Down to a sunless sea.  So twice five <i>miles</i> of fertile ground With walls and towers were <b>...</b>}}
read_test 5.6 { 
  SELECT snippet(t5, '<i>', '</i>', 'XXX') FROM t5 WHERE t5 MATCH 'miles'
} {{XXX Down to a sunless sea.  So twice five <i>miles</i> of fertile ground With walls and towers were XXX}}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test that an empty MATCH expression returns an empty result set. As
# does passing a NULL value as a MATCH expression.
#
set DO_MALLOC_TEST 0
ddl_test   6.1 { CREATE VIRTUAL TABLE t6 USING fts3(x) }
write_test 6.2 t5_content { INSERT INTO t6 VALUES('a'); }
write_test 6.3 t5_content { INSERT INTO t6 VALUES('b'); }
write_test 6.4 t5_content { INSERT INTO t6 VALUES('c'); }
read_test  6.5 { SELECT * FROM t6 WHERE t6 MATCH '' } {}
read_test  6.6 { SELECT * FROM t6 WHERE x MATCH '' } {}
read_test  6.7 { SELECT * FROM t6 WHERE t6 MATCH NULL } {}
read_test  6.8 { SELECT * FROM t6 WHERE x MATCH NULL } {}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test a few facets of the FTS3 xFilter() callback implementation:
#
#   1. That the sqlite3_index_constraint.usable flag is respected.
#
#   2. That it is an error to use the "docid" or "rowid" column of
#      an FTS3 table as the LHS of a MATCH operator.
#
#   3. That it is an error to AND together two MATCH expressions in 
#      that refer to a single FTS3 table in a WHERE clause.
#
#
set DO_MALLOC_TEST 0
ddl_test   7.1.1 { CREATE VIRTUAL TABLE t7 USING fts3(a) }
ddl_test   7.1.2 { CREATE VIRTUAL TABLE t8 USING fts3(b) }
write_test 7.1.3 t7_content { INSERT INTO t7(docid, a) VALUES(4,'number four') }
write_test 7.1.4 t7_content { INSERT INTO t7(docid, a) VALUES(5,'number five') }
write_test 7.1.5 t8_content { INSERT INTO t8(docid, b) VALUES(4,'letter D') }
write_test 7.1.6 t8_content { INSERT INTO t8(docid, b) VALUES(5,'letter E') }
read_test  7.1.7 {
  SELECT a || ':' || b FROM t7 JOIN t8 USING(docid)
} {{number four:letter D} {number five:letter E}}

error_test 7.2.1 {
  SELECT * FROM t7 WHERE docid MATCH 'number'
} {unable to use function MATCH in the requested context}
error_test 7.2.2 {
  SELECT * FROM t7 WHERE rowid MATCH 'number'
} {unable to use function MATCH in the requested context}

error_test 7.3.1 {
  SELECT * FROM t7 WHERE a MATCH 'number' AND a MATCH 'four'
} {unable to use function MATCH in the requested context}
error_test 7.3.2 {
  SELECT * FROM t7, t8 WHERE a MATCH 'number' AND a MATCH 'four'
} {unable to use function MATCH in the requested context}
error_test 7.3.3 {
  SELECT * FROM t7, t8 WHERE b MATCH 'letter' AND b MATCH 'd'
} {unable to use function MATCH in the requested context}
read_test 7.3.4 {
  SELECT * FROM t7, t8 WHERE a MATCH 'number' AND b MATCH 'letter'
} {{number four} {letter D} {number four} {letter E} {number five} {letter D} {number five} {letter E}}
read_test 7.3.5 {
  SELECT * FROM t7 WHERE a MATCH 'number' AND docid = 4
} {{number four}}

#-------------------------------------------------------------------------
# Test the quoting of FTS3 table column names. Names may be quoted using
# any of "", '', ``` or [].
#
set DO_MALLOC_TEST 0
ddl_test  8.1.1 { CREATE VIRTUAL TABLE t9a USING fts3("c1", [c2]) }
ddl_test  8.1.2 { CREATE VIRTUAL TABLE t9b USING fts3('c1', `c2`) }
read_test 8.1.3 { PRAGMA table_info(t9a) } {0 c1 {} 0 {} 0 1 c2 {} 0 {} 0}
read_test 8.1.4 { PRAGMA table_info(t9b) } {0 c1 {} 0 {} 0 1 c2 {} 0 {} 0}
ddl_test  8.2.1 { CREATE VIRTUAL TABLE t9c USING fts3("c""1", 'c''2') }
read_test 8.2.2 { PRAGMA table_info(t9c) } {0 c\"1 {} 0 {} 0 1 c'2 {} 0 {} 0}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test that FTS3 tables can be renamed using the ALTER RENAME command.
# OOM errors are tested during ALTER RENAME commands also.
#
foreach DO_MALLOC_TEST {0 1 2} {
  db close
  file delete -force test.db test.db-journal
  sqlite3 db test.db
  if {$DO_MALLOC_TEST} { sqlite3_db_config_lookaside db 0 0 0 }

  ddl_test   9.1.1             { CREATE VIRTUAL TABLE t10 USING fts3(x) }
  write_test 9.1.2 t10_content { INSERT INTO t10 VALUES('fts3 tables') }
  write_test 9.1.3 t10_content { INSERT INTO t10 VALUES('are renameable') }

  read_test  9.1.4 {
    SELECT * FROM t10 WHERE t10 MATCH 'table*'
  } {{fts3 tables}}
  read_test  9.1.5 {
    SELECT * FROM t10 WHERE x MATCH 'rename*'
  } {{are renameable}}

  ddl_test   9.1.6             { ALTER TABLE t10 RENAME TO t11 }

  read_test  9.1.7 {
    SELECT * FROM t11 WHERE t11 MATCH 'table*'
  } {{fts3 tables}}
  read_test  9.1.8 {
    SELECT * FROM t11 WHERE x MATCH 'rename*'
  } {{are renameable}}
}
#-------------------------------------------------------------------------

#-------------------------------------------------------------------------
# Test a couple of cases involving corrupt data structures:
#
#   1) A case where a document referenced by the full-text index is
#      not present in the %_content table.
#
#   2) A badly formatted b-tree segment node.
#
set DO_MALLOC_TEST 0
ddl_test   10.1.1 { CREATE VIRTUAL TABLE ta USING fts3 }
write_test 10.1.2 ta_content { 
  INSERT INTO ta VALUES('During a summer vacation in 1790') }
write_test 10.1.3 ta_content {
  INSERT INTO ta VALUES('Wordsworth went on a walking tour') }
write_test 10.1.4 ta_content { DELETE FROM ta_content WHERE rowid = 2 }
read_test  10.1.5 {
  SELECT * FROM ta WHERE ta MATCH 'summer'
} {{During a summer vacation in 1790}}
error_test 10.1.6 {
  SELECT * FROM ta WHERE ta MATCH 'walking'
} {database disk image is malformed}

write_test 10.2.1 ta_content { DELETE FROM ta }
write_test 10.2.2 ta_content { 
  INSERT INTO ta VALUES('debate demonstrated the rising difficulty') }
write_test 10.2.3 ta_content { 
  INSERT INTO ta VALUES('Google released its browser beta') }

set blob [db one {SELECT root FROM ta_segdir WHERE rowid = 2}]
binary scan $blob "a6 a3 a*" start middle end
set middle "\x0E\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\x06\x06"
set blob [binary format "a6 a* a*" $start $middle $end]
write_test 10.2.4 ta_segdir { 
  UPDATE ta_segdir SET root = $blob WHERE rowid = 2
}
error_test 10.2.5 {
  SELECT * FROM ta WHERE ta MATCH 'beta'
} {database disk image is malformed}


finish_test

  join $lDoc " "
}

###########################################################################

proc gobble_varint {varname} {
  upvar $varname blob
  set n [read_varint $blob ret]
  set blob [string range $blob $n end]
  return $ret
}
proc gobble_string {varname nLength} {
  upvar $varname blob
  set ret [string range $blob 0 [expr $nLength-1]]
  set blob [string range $blob $nLength end]
................................................................................
# by parameter $result, or (b) TCL throws an "out of memory" error.
#
# If DO_MALLOC_TEST is defined and set to zero, then the SELECT statement
# is executed just once. In this case the test case passes if the results
# match the expected results passed via parameter $result.
#
proc do_select_test {name sql result} {
  doPassiveTest $name $sql [list 0 $result]




}

proc do_error_test {name sql error} {
  doPassiveTest $name $sql [list 1 $error]
}

proc doPassiveTest {name sql catchres} {
  if {![info exists ::DO_MALLOC_TEST]} { set ::DO_MALLOC_TEST 1 }

  if {$::DO_MALLOC_TEST} {
    set answers [list {1 {out of memory}} $catchres]
    set modes [list 100000 transient 1 persistent]
  } else {
    set answers [list $catchres]

    set modes [list 0 nofail]




  }

















  set str [join $answers " OR "]

  foreach {nRepeat zName} $modes {


    for {set iFail 1} 1 {incr iFail} {
      if {$::DO_MALLOC_TEST} {sqlite3_memdebug_fail $iFail -repeat $nRepeat}





      set res [catchsql $sql]
      if {[lsearch -exact $answers $res]>=0} {
        set res $str


      }
      do_test $name.$zName.$iFail [list set {} $res] $str
      set nFail [sqlite3_memdebug_fail -1 -benigncnt nBenign]
      if {$nFail==0} break

    }
  }
}


#-------------------------------------------------------------------------
# Test a single write to the database. In this case a  "write" is a 

  join $lDoc " "
}

###########################################################################

proc gobble_varint {varname} {
  upvar $varname blob
  set n [read_fts3varint $blob ret]
  set blob [string range $blob $n end]
  return $ret
}
proc gobble_string {varname nLength} {
  upvar $varname blob
  set ret [string range $blob 0 [expr $nLength-1]]
  set blob [string range $blob $nLength end]
................................................................................
# by parameter $result, or (b) TCL throws an "out of memory" error.
#
# If DO_MALLOC_TEST is defined and set to zero, then the SELECT statement
# is executed just once. In this case the test case passes if the results
# match the expected results passed via parameter $result.
#
proc do_select_test {name sql result} {
  uplevel [list doPassiveTest 0 $name $sql [list 0 $result]]
}

proc do_restart_select_test {name sql result} {
  uplevel [list doPassiveTest 1 $name $sql [list 0 $result]]
}

proc do_error_test {name sql error} {
  uplevel [list doPassiveTest 0 $name $sql [list 1 $error]]
}

proc doPassiveTest {isRestart name sql catchres} {
  if {![info exists ::DO_MALLOC_TEST]} { set ::DO_MALLOC_TEST 1 }

  switch $::DO_MALLOC_TEST {
    0 { # No malloc failures.
      do_test $name [list catchsql $sql] $catchres
      return

    }
    1 { # Simulate transient failures.
      set nRepeat 1
      set zName "transient"
      set nStartLimit 100000
      set nBackup 1
    }
    2 { # Simulate persistent failures.
      set nRepeat 1
      set zName "persistent"
      set nStartLimit 100000
      set nBackup 1
    }
    3 { # Simulate transient failures with extra brute force.
      set nRepeat 100000
      set zName "ridiculous"
      set nStartLimit 1
      set nBackup 10
    }
  }

  # The set of acceptable results from running [catchsql $sql].
  #
  set answers [list {1 {out of memory}} $catchres]
  set str [join $answers " OR "]


  set nFail 1
  for {set iLimit $nStartLimit} {$nFail} {incr iLimit} {
    for {set iFail 1} {$nFail && $iFail<=$iLimit} {incr iFail} {

      for {set iTest 0} {$iTest<$nBackup && ($iFail-$iTest)>0} {incr iTest} {

        if {$isRestart} { sqlite3 db test.db }

        sqlite3_memdebug_fail [expr $iFail-$iTest] -repeat $nRepeat
        set res [uplevel [list catchsql $sql]]
        if {[lsearch -exact $answers $res]>=0} { set res $str }

        set testname "$name.$zName.$iFail"
        do_test "$name.$zName.$iLimit.$iFail" [list set {} $res] $str


        set nFail [sqlite3_memdebug_fail -1 -benigncnt nBenign]

      }
    }
  }
}


#-------------------------------------------------------------------------
# Test a single write to the database. In this case a  "write" is a 

# 2009 December 03
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# The tests in this file are structural coverage tests. They are designed
# to complement the tests in fts3rnd.test and fts3doc.test. Between them,
# the three files should provide full coverage of the fts3 extension code.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build does not include FTS3, skip the tests in this file.
#
ifcapable !fts3 { finish_test ; return }
source $testdir/fts3_common.tcl
source $testdir/malloc_common.tcl

set DO_MALLOC_TEST 0

#--------------------------------------------------------------------------
# When it first needs to read a block from the %_segments table, the FTS3 
# module compiles an SQL statement for that purpose. The statement is 
# stored and reused each subsequent time a block is read. This test case 
# tests the effects of an OOM error occuring while compiling the statement.
#
# Similarly, when FTS3 first needs to scan through a set of segment leaves
# to find a set of documents that matches a term, it allocates a string
# containing the text of the required SQL, and compiles one or more 
# statements to traverse the leaves. This test case tests that OOM errors
# that occur while allocating this string and statement are handled correctly
# also.
#
do_test fts3cov-1.1 {
  execsql { 
    CREATE VIRTUAL TABLE t1 USING fts3(x);
    INSERT INTO t1(t1) VALUES('nodesize=24');
    BEGIN;
      INSERT INTO t1 VALUES('Is the night chilly and dark?');
      INSERT INTO t1 VALUES('The night is chilly, but not dark.');
      INSERT INTO t1 VALUES('The thin gray cloud is spread on high,');
      INSERT INTO t1 VALUES('It covers but not hides the sky.');
    COMMIT;
    SELECT count(*)>0 FROM t1_segments;
  }
} {1}

set DO_MALLOC_TEST 1
do_restart_select_test fts3cov-1.2 {
  SELECT docid FROM t1 WHERE t1 MATCH 'chilly';
} {1 2}
set DO_MALLOC_TEST 0

#--------------------------------------------------------------------------
# When querying the full-text index, if an expected internal node block is 
# missing from the %_segments table, or if a NULL value is stored in the 
# %_segments table instead of a binary blob, database corruption should be 
# reported.
#
# Even with tiny 24 byte nodes, it takes a fair bit of data to produce a
# segment b-tree that uses the %_segments table to store internal nodes. 
#
do_test fts3cov-2.1 {
  execsql {
    INSERT INTO t1(t1) VALUES('nodesize=24');
    BEGIN;
      INSERT INTO t1 VALUES('The moon is behind, and at the full;');
      INSERT INTO t1 VALUES('And yet she looks both small and dull.');
      INSERT INTO t1 VALUES('The night is chill, the cloud is gray:');
      INSERT INTO t1 VALUES('''T is a month before the month of May,');
      INSERT INTO t1 VALUES('And the Spring comes slowly up this way.');
      INSERT INTO t1 VALUES('The lovely lady, Christabel,');
      INSERT INTO t1 VALUES('Whom her father loves so well,');
      INSERT INTO t1 VALUES('What makes her in the wood so late,');
      INSERT INTO t1 VALUES('A furlong from the castle gate?');
      INSERT INTO t1 VALUES('She had dreams all yesternight');
      INSERT INTO t1 VALUES('Of her own betrothed knight;');
      INSERT INTO t1 VALUES('And she in the midnight wood will pray');
      INSERT INTO t1 VALUES('For the weal of her lover that''s far away.');
    COMMIT;

    INSERT INTO t1(t1) VALUES('optimize');
    SELECT substr(hex(root), 1, 2) FROM t1_segdir;
  }
} {03}

# Test the "missing entry" case:
do_test fts3cov-2.1 {
  set root [db one {SELECT root FROM t1_segdir}]
  read_fts3varint [string range $root 1 end] left_child
  execsql { DELETE FROM t1_segments WHERE blockid = $left_child }
} {}
do_error_test fts3cov-2.2 {
  SELECT * FROM t1 WHERE t1 MATCH 'c*'
} {database disk image is malformed}

# Test the "replaced with NULL" case:
do_test fts3cov-2.3 {
  execsql { INSERT INTO t1_segments VALUES($left_child, NULL) }
} {}
do_error_test fts3cov-2.4 {
  SELECT * FROM t1 WHERE t1 MATCH 'cloud'
} {database disk image is malformed}

#--------------------------------------------------------------------------
# The following tests are to test the effects of OOM errors while storing
# terms in the pending-hash table. Specifically, while creating doclist
# blobs to store in the table. More specifically, to test OOM errors while
# appending column numbers to doclists. For example, if a doclist consists
# of:
#
#   <docid> <column 0 offset-list> 0x01 <column N> <column N offset-list>
#
# The following tests check that malloc errors encountered while appending
# the "0x01 <column N>" data to the dynamically growable blob used to 
# accumulate the doclist in memory are handled correctly.
#
do_test fts3cov-3.1 {
  set cols [list]
  set vals [list]
  for {set i 0} {$i < 120} {incr i} {
    lappend cols "col$i"
    lappend vals "'word'"
  }
  execsql "CREATE VIRTUAL TABLE t2 USING fts3([join $cols ,])"
} {}
set DO_MALLOC_TEST 1 
do_write_test fts3cov-3.2 t2_content "
  INSERT INTO t2(docid, [join $cols ,]) VALUES(1, [join $vals ,])
"
do_write_test fts3cov-3.3 t2_content "
  INSERT INTO t2(docid, [join $cols ,]) VALUES(200, [join $vals ,])
"
do_write_test fts3cov-3.4 t2_content "
  INSERT INTO t2(docid, [join $cols ,]) VALUES(60000, [join $vals ,])
"

#-------------------------------------------------------------------------
# If too much data accumulates in the pending-terms hash table, it is
# flushed to the database automatically, even if the transaction has not
# finished. The following tests check the effects of encountering an OOM 
# while doing this.
#
do_test fts3cov-4.1 {
  execsql {
    CREATE VIRTUAL TABLE t3 USING fts3(x);
    INSERT INTO t3(t3) VALUES('nodesize=24');
    INSERT INTO t3(t3) VALUES('maxpending=100');
  }
} {}
set DO_MALLOC_TEST 1 
do_write_test fts3cov-4.2 t3_content {
  INSERT INTO t3(docid, x)
    SELECT 1, 'Then Christabel stretched forth her hand,' UNION ALL
    SELECT 3, 'And comforted fair Geraldine:'             UNION ALL
    SELECT 4, '''O well, bright dame, may you command'    UNION ALL
    SELECT 5, 'The service of Sir Leoline;'               UNION ALL
    SELECT 2, 'And gladly our stout chivalry'             UNION ALL
    SELECT 7, 'Will he send forth, and friends withal,'   UNION ALL
    SELECT 8, 'To guide and guard you safe and free'      UNION ALL
    SELECT 6, 'Home to your noble father''s hall.'''
}

#-------------------------------------------------------------------------
# When building the internal tree structure for each segment b-tree, FTS3
# assumes that the content of each internal node will be less than
# $nodesize bytes, where $nodesize is the advisory node size. If this turns
# out to be untrue, then an extra buffer must be malloc'd for each term.
# This test case tests these paths and the effects of said mallocs failing
# by inserting insert a document with some fairly large terms into a
# full-text table with a very small node-size. 
#
# Test this handling of large terms in three contexts:
#
#   1. When flushing the pending-terms table.
#   2. When optimizing the data structures using the INSERT syntax. 
#   2. When optimizing the data structures using the deprecated SELECT syntax. 
#
do_test fts3cov-5.1 {
  execsql {
    CREATE VIRTUAL TABLE t4 USING fts3(x);
    INSERT INTO t4(t4) VALUES('nodesize=24');
  }
} {}
set DO_MALLOC_TEST 1

# Test when flushing pending-terms table.
do_write_test fts3cov-5.2 t4_content {
  INSERT INTO t4
    SELECT 'ItisanancientMarinerAndhestoppethoneofthreeAA' UNION ALL
    SELECT 'ItisanancientMarinerAndhestoppethoneofthreeBB' UNION ALL
    SELECT 'ItisanancientMarinerAndhestoppethoneofthreeCC' UNION ALL
    SELECT 'BythylonggreybeardandglitteringeyeNowwhereforestoppstAA' UNION ALL
    SELECT 'BythylonggreybeardandglitteringeyeNowwhereforestoppstBB' UNION ALL
    SELECT 'BythylonggreybeardandglitteringeyeNowwhereforestoppstCC'
}

# Test when optimizing via INSERT.
do_test fts3cov-5.3 { execsql { INSERT INTO t4 VALUES('extra!') } } {}
do_write_test fts3cov-5.2 t4_segments { INSERT INTO t4(t4) VALUES('optimize') }

# Test when optimizing via SELECT.
do_test fts3cov-5.5 { execsql { INSERT INTO t4 VALUES('more extra!') } } {}
do_write_test fts3cov-5.6 t4_segments {
  SELECT * FROM (SELECT optimize(t4) FROM t4 LIMIT 1)
  EXCEPT SELECT 'Index optimized'
}

#-------------------------------------------------------------------------
# When merging all segments at a given level to create a single segment
# at level+1, FTS3 runs a query of the form:
#
#   SELECT count(*) FROM %_segdir WHERE level = ?
#
# The query is compiled the first time this operation is required and
# reused thereafter. This test aims to test the effects of an OOM while
# preparing and executing this query for the first time.
#
# Then, keep inserting rows into the table so that the effects of an OOM
# while re-executing the same query can also be tested.
#
do_test fts3cov-6.1 {
  execsql { CREATE VIRTUAL TABLE t5 USING fts3(x) }
  for {set i 0} {$i<16} {incr i} { execsql "INSERT INTO t5 VALUES('term$i')" }
  execsql { SELECT count(*) FROM t5_segdir }
} {16}

# First time.
db close
sqlite3 db test.db
do_write_test fts3cov-6.2 t5_content {
  INSERT INTO t5 VALUES('segment number 16!');
}

# Second time.
do_test fts3cov-6.3 {
  for {set i 1} {$i<16} {incr i} { execsql "INSERT INTO t5 VALUES('term$i')" }
  execsql { SELECT count(*) FROM t5_segdir }
} {17}
do_write_test fts3cov-6.4 t5_content {
  INSERT INTO t5 VALUES('segment number 16!');
}

#-------------------------------------------------------------------------
# Update the docid of a row. Test this in two scenarios:
#
#   1. When the row being updated is the only row in the table.
#   2. When it is not.
#
# The two cases above take different paths because in case 1 all data 
# structures can simply be emptied before inserting the new row record.
# In case 2, the data structures actually have to be updated.
#
do_test fts3cov-7.1 {
  execsql {
    CREATE VIRTUAL TABLE t7 USING fts3(a, b, c);
    INSERT INTO t7 VALUES('A', 'B', 'C');
    UPDATE t7 SET docid = 5;
    SELECT docid, * FROM t7;
  }
} {5 A B C}
do_test fts3cov-7.2 {
  execsql {
    INSERT INTO t7 VALUES('D', 'E', 'F');
    UPDATE t7 SET docid = 1 WHERE docid = 6;
    SELECT docid, * FROM t7;
  }
} {1 D E F 5 A B C}

#-------------------------------------------------------------------------
# If a set of documents are modified within a transaction, the 
# pending-terms table must be flushed each time a document with a docid
# less than or equal to the previous docid is modified. 
#
# This test checks the effects of an OOM error occuring when the 
# pending-terms table is flushed for this reason as part of a DELETE 
# statement.
#
do_malloc_test fts3cov-8 -sqlprep {
  BEGIN;
    CREATE VIRTUAL TABLE t8 USING fts3;
    INSERT INTO t8 VALUES('the output of each batch run');
    INSERT INTO t8 VALUES('(possibly a day''s work)');
    INSERT INTO t8 VALUES('was written to two separate disks');
  COMMIT;
} -sqlbody {
  BEGIN;
    DELETE FROM t8 WHERE rowid = 3;
    DELETE FROM t8 WHERE rowid = 2;
    DELETE FROM t8 WHERE rowid = 1;
  COMMIT;
}

#-------------------------------------------------------------------------
# Test some branches in the code that handles "special" inserts like:
#
#   INSERT INTO t1(t1) VALUES('optimize');
#
# Also test that an optimize (INSERT method) works on an empty table.
#
set DO_MALLOC_TEST 0
do_test fts3cov-9.1 {
  execsql { CREATE VIRTUAL TABLE xx USING fts3 }
} {}
do_error_test fts3cov-9.2 {
  INSERT INTO xx(xx) VALUES('optimise');   -- British spelling
} {SQL logic error or missing database}
do_error_test fts3cov-9.3 {
  INSERT INTO xx(xx) VALUES('short');
} {SQL logic error or missing database}
do_error_test fts3cov-9.4 {
  INSERT INTO xx(xx) VALUES('waytoolongtobecorrect');
} {SQL logic error or missing database}
do_test fts3cov-9.5 {
  execsql { INSERT INTO xx(xx) VALUES('optimize') }
} {}

#-------------------------------------------------------------------------
# Test that a table can be optimized in the middle of a transaction when
# the pending-terms table is non-empty. This case involves some extra
# branches because data must be read not only from the database, but
# also from the pending-terms table.
#
do_malloc_test fts3cov-10 -sqlprep {
  CREATE VIRTUAL TABLE t10 USING fts3;
  INSERT INTO t10 VALUES('Optimising images for the web is a tricky business');
  BEGIN;
    INSERT INTO t10 VALUES('You have to get the right balance between');
} -sqlbody {
  INSERT INTO t10(t10) VALUES('optimize');
}

#-------------------------------------------------------------------------
# Test a full-text query for a term that was once in the index, but is
# no longer.
#
do_test fts3cov-11.1 {
  execsql { 
    CREATE VIRTUAL TABLE xx USING fts3;
    INSERT INTO xx VALUES('one two three');
    INSERT INTO xx VALUES('four five six');
    DELETE FROM xx WHERE docid = 1;
  }
  execsql { SELECT * FROM xx WHERE xx MATCH 'two' }
} {}


do_malloc_test fts3cov-12 -sqlprep {
  CREATE VIRTUAL TABLE t12 USING fts3;
  INSERT INTO t12 VALUES('is one of the two togther');
  BEGIN;
    INSERT INTO t12 VALUES('one which was appropriate at the time');
} -sqlbody {
  SELECT * FROM t12 WHERE t12 MATCH 'one'
}

do_malloc_test fts3cov-13 -sqlprep {
  PRAGMA encoding = 'UTF-16';
  CREATE VIRTUAL TABLE t13 USING fts3;
  INSERT INTO t13 VALUES('two scalar functions');
  INSERT INTO t13 VALUES('scalar two functions');
  INSERT INTO t13 VALUES('functions scalar two');
} -sqlbody {
  SELECT snippet(t13, '%%', '%%', '#') FROM t13 WHERE t13 MATCH 'two';
  SELECT snippet(t13, '%%', '%%') FROM t13 WHERE t13 MATCH 'two';
  SELECT snippet(t13, '%%') FROM t13 WHERE t13 MATCH 'two';
}

finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Brute force (random data) tests for FTS3.
#



































































set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build does not include FTS3, skip the tests in this file.
#
ifcapable !fts3 { finish_test ; return }
source $testdir/fts3_common.tcl



set nVocab 100
set lVocab [list]



# Generate a vocabulary of nVocab words. Each word is 3 characters long.
#
set lChar {a b c d e f g h i j k l m n o p q r s t u v w x y z}
for {set i 0} {$i < $nVocab} {incr i} {

  set    word [lindex $lChar [expr int(rand()*26)]]
  append word [lindex $lChar [expr int(rand()*26)]]
  append word [lindex $lChar [expr int(rand()*26)]]

  lappend lVocab $word
}

proc random_term {} {
  lindex $::lVocab [expr {int(rand()*$::nVocab)}]
}

................................................................................
  set doc  [generate_doc [expr int((rand()*100))]]
  lset ::t1($rowid) $iCol $doc
  execsql "UPDATE t1 SET [lindex $cols $iCol] = \$doc WHERE rowid = \$rowid"
}

proc simple_phrase {zPrefix} {
  set ret [list]
  set pattern "*[string map {* \[a-z\]} $zPrefix]*"




  foreach {key value} [array get ::t1] {
    if {[string match $pattern $value]} { lappend ret $key }


  }


  lsort -integer $ret
}

proc simple_near {termlist nNear} {
  set ret [list]

  foreach {key value} [array get ::t1] {
    foreach v $value {

      set l [lsearch -exact -all $v [lindex $termlist 0]]
................................................................................
foreach nodesize {50 500 1000 2000} {
  catch { array unset ::t1 }

  # Create the FTS3 table. Populate it (and the Tcl array) with 100 rows.
  #
  db transaction {
    catchsql { DROP TABLE t1 }
    execsql "CREATE VIRTUAL TABLE t1 USING fts3(a, b, c, test:$nodesize)"

    for {set i 0} {$i < 100} {incr i} { insert_row $i }
  }
  
  for {set iTest 1} {$iTest <= 100} {incr iTest} {








  
    # Delete one row, update one row and insert one row.
    #
    set rows [array names ::t1]
    set nRow [llength $rows]
    set iUpdate [lindex $rows [expr {int(rand()*$nRow)}]]
    set iDelete $iUpdate
................................................................................
    while {$iDelete == $iUpdate} {
      set iDelete [lindex $rows [expr {int(rand()*$nRow)}]]
    }
    set iInsert $iUpdate
    while {[info exists ::t1($iInsert)]} {
      set iInsert [expr {int(rand()*1000000)}]
    }
    db transaction {
      insert_row $iInsert
      update_row $iUpdate
      delete_row $iDelete
    }

    # Pick 10 terms from the vocabulary. Check that the results of querying
    # the database for the set of documents containing each of these terms
    # is the same as the result obtained by scanning the contents of the Tcl 
    # array for each term.
    #
    for {set i 0} {$i < 10} {incr i} {
      set term [random_term]
      do_test fts3rnd-1.$nodesize.$iTest.1.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $term }
      } [simple_phrase $term]
    }

    # This time, use the first two characters of each term as a term prefix
    # to query for. Test that querying the Tcl array produces the same results
    # as querying the FTS3 table for the prefix.
    #
    for {set i 0} {$i < 10} {incr i} {
      set prefix [string range [random_term] 0 1]
      set match "${prefix}*"
      do_test fts3rnd-1.$nodesize.$iTest.2.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_phrase $match]
    }

    # Similar to the above, except for phrase queries.
    #
    for {set i 0} {$i < 10} {incr i} {
      set term [list [random_term] [random_term]]
      set match "\"$term\""
      do_test fts3rnd-1.$nodesize.$iTest.3.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_phrase $term]
    }

    # Three word phrases.
    #
    for {set i 0} {$i < 10} {incr i} {
      set term [list [random_term] [random_term] [random_term]]
      set match "\"$term\""
      do_test fts3rnd-1.$nodesize.$iTest.4.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_phrase $term]
    }

    # Three word phrases made up of term-prefixes.
    #
    for {set i 0} {$i < 10} {incr i} {
      set    query "[string range [random_term] 0 1]* "
      append query "[string range [random_term] 0 1]* "
      append query "[string range [random_term] 0 1]*"

      set match "\"$query\""
      do_test fts3rnd-1.$nodesize.$iTest.5.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_phrase $query]
    }

    # A NEAR query with terms as the arguments.
    #
    for {set i 0} {$i < 10} {incr i} {
      set terms [list [random_term] [random_term]]
      set match [join $terms " NEAR "]
      do_test fts3rnd-1.$nodesize.$iTest.6.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_near $terms 10]
    }

    # A 3-way NEAR query with terms as the arguments.
    #
    for {set i 0} {$i < 10} {incr i} {
      set terms [list [random_term] [random_term] [random_term]]
      set nNear 11
      set match [join $terms " NEAR/$nNear "]
      set fts3 [execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }]
      do_test fts3rnd-1.$nodesize.$iTest.7.$i {
        execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
      } [simple_near $terms $nNear]
    }
    
    # Set operations on simple term queries.
    #
    foreach {tn op proc} {
      8  OR  setop_or
      9  NOT setop_not
      10 AND setop_and
    } {
      for {set i 0} {$i < 10} {incr i} {
        set term1 [random_term]
        set term2 [random_term]
        set match "$term1 $op $term2"
        do_test fts3rnd-1.$nodesize.$iTest.$tn.$i {
          execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
        } [$proc [simple_phrase $term1] [simple_phrase $term2]]
      }
    }
 
    # Set operations on NEAR queries.
    #
    foreach {tn op proc} {
      8  OR  setop_or
      9  NOT setop_not
      10 AND setop_and
    } {
      for {set i 0} {$i < 10} {incr i} {
        set term1 [random_term]
        set term2 [random_term]
        set term3 [random_term]
        set term4 [random_term]
        set match "$term1 NEAR $term2 $op $term3 NEAR $term4"
        do_test fts3rnd-1.$nodesize.$iTest.$tn.$i {
          execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }
        } [$proc                                  \
            [simple_near [list $term1 $term2] 10] \
            [simple_near [list $term3 $term4] 10]
          ]
      }
    }


  }
}

finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# Brute force (random data) tests for FTS3.
#

#-------------------------------------------------------------------------
#
# The FTS3 tests implemented in this file focus on testing that FTS3
# returns the correct set of documents for various types of full-text
# query. This is done using pseudo-randomly generated data and queries.
# The expected result of each query is calculated using Tcl code.
#
#   1. The database is initialized to contain a single table with three
#      columns. 100 rows are inserted into the table. Each of the three
#      values in each row is a document consisting of between 0 and 100
#      terms. Terms are selected from a vocabulary of $G(nVocab) terms.
#
#   2. The following is performed 100 times:
#
#      a. A row is inserted into the database. The row contents are 
#         generated as in step 1. The docid is a pseudo-randomly selected
#         value between 0 and 1000000.
# 
#      b. A psuedo-randomly selected row is updated. One of its columns is
#         set to contain a new document generated in the same way as the
#         documents in step 1.
# 
#      c. A psuedo-randomly selected row is deleted.
# 
#      d. For each of several types of fts3 queries, 10 SELECT queries
#         of the form:
# 
#           SELECT docid FROM <tbl> WHERE <tbl> MATCH '<query>'
# 
#         are evaluated. The results are compared to those calculated by
#         Tcl code in this file. The patterns used for the different query
#         types are:
# 
#           1.  query = <term>
#           2.  query = <prefix>
#           3.  query = "<term> <term>"
#           4.  query = "<term> <term> <term>"
#           5.  query = "<prefix> <prefix> <prefix>"
#           6.  query = <term> NEAR <term>
#           7.  query = <term> NEAR/11 <term> NEAR/11 <term>
#           8.  query = <term> OR <term>
#           9.  query = <term> NOT <term>
#           10. query = <term> AND <term>
#           11. query = <term> NEAR <term> OR <term> NEAR <term>
#           12. query = <term> NEAR <term> NOT <term> NEAR <term>
#           13. query = <term> NEAR <term> AND <term> NEAR <term>
# 
#         where <term> is a term psuedo-randomly selected from the vocabulary
#         and prefix is the first 2 characters of such a term followed by
#         a "*" character.
#     
#      Every second iteration, steps (a) through (d) above are performed
#      within a single transaction. This forces the queries in (d) to
#      read data from both the database and the in-memory hash table
#      that caches the full-text index entries created by steps (a), (b)
#      and (c) until the transaction is committed.
#
# The procedure above is run 5 times, using advisory fts3 node sizes of 50,
# 500, 1000 and 2000 bytes.
#
# After the test using an advisory node-size of 50, an OOM test is run using
# the database. This test is similar to step (d) above, except that it tests
# the effects of transient and persistent OOM conditions encountered while
# executing each query.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If this build does not include FTS3, skip the tests in this file.
#
ifcapable !fts3 { finish_test ; return }
source $testdir/fts3_common.tcl

set G(nVocab) 100

set nVocab 100
set lVocab [list]

expr srand(0)

# Generate a vocabulary of nVocab words. Each word is 3 characters long.
#
set lChar {a b c d e f g h i j k l m n o p q r s t u v w x y z}
for {set i 0} {$i < $nVocab} {incr i} {
  set len [expr int(rand()*3)+2]
  set    word [lindex $lChar [expr int(rand()*26)]]
  append word [lindex $lChar [expr int(rand()*26)]]
  if {$len>2} { append word [lindex $lChar [expr int(rand()*26)]] }
  if {$len>3} { append word [lindex $lChar [expr int(rand()*26)]] }
  lappend lVocab $word
}

proc random_term {} {
  lindex $::lVocab [expr {int(rand()*$::nVocab)}]
}

................................................................................
  set doc  [generate_doc [expr int((rand()*100))]]
  lset ::t1($rowid) $iCol $doc
  execsql "UPDATE t1 SET [lindex $cols $iCol] = \$doc WHERE rowid = \$rowid"
}

proc simple_phrase {zPrefix} {
  set ret [list]


  set reg [string map {* {[^ ]*}} $zPrefix]
  set reg " $reg "

  foreach {key value} [array get ::t1] {

    foreach col $value {
      if {[regexp $reg " $col "]} {lappend ret $key}
    }
  }

  lsort -uniq -integer $ret
}

proc simple_near {termlist nNear} {
  set ret [list]

  foreach {key value} [array get ::t1] {
    foreach v $value {

      set l [lsearch -exact -all $v [lindex $termlist 0]]
................................................................................
foreach nodesize {50 500 1000 2000} {
  catch { array unset ::t1 }

  # Create the FTS3 table. Populate it (and the Tcl array) with 100 rows.
  #
  db transaction {
    catchsql { DROP TABLE t1 }
    execsql "CREATE VIRTUAL TABLE t1 USING fts3(a, b, c)"
    execsql "INSERT INTO t1(t1) VALUES('nodesize=$nodesize')"
    for {set i 0} {$i < 100} {incr i} { insert_row $i }
  }
  
  for {set iTest 0} {$iTest <= 100} {incr iTest} {
    catchsql COMMIT

    set DO_MALLOC_TEST 0
    set nRep 10
    if {$iTest==100 && $nodesize==50} { 
      set DO_MALLOC_TEST 1 
      set nRep 2
    }
  
    # Delete one row, update one row and insert one row.
    #
    set rows [array names ::t1]
    set nRow [llength $rows]
    set iUpdate [lindex $rows [expr {int(rand()*$nRow)}]]
    set iDelete $iUpdate
................................................................................
    while {$iDelete == $iUpdate} {
      set iDelete [lindex $rows [expr {int(rand()*$nRow)}]]
    }
    set iInsert $iUpdate
    while {[info exists ::t1($iInsert)]} {
      set iInsert [expr {int(rand()*1000000)}]
    }
    execsql BEGIN
      insert_row $iInsert
      update_row $iUpdate
      delete_row $iDelete
    if {0==($iTest%2)} { execsql COMMIT }

    # Pick 10 terms from the vocabulary. Check that the results of querying
    # the database for the set of documents containing each of these terms
    # is the same as the result obtained by scanning the contents of the Tcl 
    # array for each term.
    #
    for {set i 0} {$i < 10} {incr i} {
      set term [random_term]
      do_select_test fts3rnd-1.$nodesize.$iTest.1.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $term
      } [simple_phrase $term]
    }

    # This time, use the first two characters of each term as a term prefix
    # to query for. Test that querying the Tcl array produces the same results
    # as querying the FTS3 table for the prefix.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set prefix [string range [random_term] 0 end-1]
      set match "${prefix}*"
      do_select_test fts3rnd-1.$nodesize.$iTest.2.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match
      } [simple_phrase $match]
    }

    # Similar to the above, except for phrase queries.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set term [list [random_term] [random_term]]
      set match "\"$term\""
      do_select_test fts3rnd-1.$nodesize.$iTest.3.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match
      } [simple_phrase $term]
    }

    # Three word phrases.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set term [list [random_term] [random_term] [random_term]]
      set match "\"$term\""
      do_select_test fts3rnd-1.$nodesize.$iTest.4.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match
      } [simple_phrase $term]
    }

    # Three word phrases made up of term-prefixes.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set    query "[string range [random_term] 0 end-1]* "
      append query "[string range [random_term] 0 end-1]* "
      append query "[string range [random_term] 0 end-1]*"

      set match "\"$query\""
      do_select_test fts3rnd-1.$nodesize.$iTest.5.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match
      } [simple_phrase $query]
    }

    # A NEAR query with terms as the arguments.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set terms [list [random_term] [random_term]]
      set match [join $terms " NEAR "]
      do_select_test fts3rnd-1.$nodesize.$iTest.6.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match 
      } [simple_near $terms 10]
    }

    # A 3-way NEAR query with terms as the arguments.
    #
    for {set i 0} {$i < $nRep} {incr i} {
      set terms [list [random_term] [random_term] [random_term]]
      set nNear 11
      set match [join $terms " NEAR/$nNear "]
      set fts3 [execsql { SELECT docid FROM t1 WHERE t1 MATCH $match }]
      do_select_test fts3rnd-1.$nodesize.$iTest.7.$i {
        SELECT docid FROM t1 WHERE t1 MATCH $match
      } [simple_near $terms $nNear]
    }
    
    # Set operations on simple term queries.
    #
    foreach {tn op proc} {
      8  OR  setop_or
      9  NOT setop_not
      10 AND setop_and
    } {
      for {set i 0} {$i < $nRep} {incr i} {
        set term1 [random_term]
        set term2 [random_term]
        set match "$term1 $op $term2"
        do_select_test fts3rnd-1.$nodesize.$iTest.$tn.$i {
          SELECT docid FROM t1 WHERE t1 MATCH $match
        } [$proc [simple_phrase $term1] [simple_phrase $term2]]
      }
    }
 
    # Set operations on NEAR queries.
    #
    foreach {tn op proc} {
      8  OR  setop_or
      9  NOT setop_not
      10 AND setop_and
    } {
      for {set i 0} {$i < $nRep} {incr i} {
        set term1 [random_term]
        set term2 [random_term]
        set term3 [random_term]
        set term4 [random_term]
        set match "$term1 NEAR $term2 $op $term3 NEAR $term4"
        do_select_test fts3rnd-1.$nodesize.$iTest.$tn.$i {
          SELECT docid FROM t1 WHERE t1 MATCH $match
        } [$proc                                  \
            [simple_near [list $term1 $term2] 10] \
            [simple_near [list $term3 $term4] 10]
          ]
      }
    }

    catchsql COMMIT
  }
}

finish_test

# 2009 December 9
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for N-way joins (N>2) which make
# use of USING or NATURAL JOIN.  For such joins, the USING and
# NATURAL JOIN processing needs to search all tables to the left
# of the join looking for a match.  See ticket [f74beaabde]
# for additional information.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl


# The problem as initially reported on the mailing list:
#
do_test join6-1.1 {
  execsql {
    CREATE TABLE t1(a);
    CREATE TABLE t2(a);
    CREATE TABLE t3(a,b);
    INSERT INTO t1 VALUES(1);
    INSERT INTO t3 VALUES(1,2);

    SELECT * FROM t1 LEFT JOIN t2 USING(a) LEFT JOIN t3 USING(a);
  }
} {1 2}
do_test join6-1.2 {
  execsql {
    SELECT t1.a, t3.b 
      FROM t1 LEFT JOIN t2 ON t1.a=t2.a LEFT JOIN t3 ON t2.a=t3.a;
  }
} {1 {}}
do_test join6-1.3 {
  execsql {
    SELECT t1.a, t3.b
      FROM t1 LEFT JOIN t2 ON t1.a=t2.a LEFT JOIN t3 ON t1.a=t3.a;
  }
} {1 2}


do_test join6-2.1 {
  execsql {
    DROP TABLE t1;
    DROP TABLE t2;
    DROP TABLE t3;

    CREATE TABLE t1(x,y);
    CREATE TABLE t2(y,z);
    CREATE TABLE t3(x,z);

    INSERT INTO t1 VALUES(1,2);
    INSERT INTO t1 VALUES(3,4);

    INSERT INTO t2 VALUES(2,3);
    INSERT INTO t2 VALUES(4,5);

    INSERT INTO t3 VALUES(1,3);
    INSERT INTO t3 VALUES(3,5);

    SELECT * FROM t1 JOIN t2 USING (y) JOIN t3 USING(x);
  }
} {1 2 3 3 3 4 5 5}
do_test join6-2.2 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 NATURAL JOIN t3;
  }
} {1 2 3 3 4 5}


do_test join6-3.1 {
  execsql {
    DROP TABLE t1;
    DROP TABLE t2;
    DROP TABLE t3;

    CREATE TABLE t1(a,x,y);
    INSERT INTO t1 VALUES(1,91,92);
    INSERT INTO t1 VALUES(2,93,94);
    
    CREATE TABLE t2(b,y,z);
    INSERT INTO t2 VALUES(3,92,93);
    INSERT INTO t2 VALUES(4,94,95);
    
    CREATE TABLE t3(c,x,z);
    INSERT INTO t3 VALUES(5,91,93);
    INSERT INTO t3 VALUES(6,99,95);
    
    SELECT * FROM t1 NATURAL JOIN t2 NATURAL JOIN t3;
  }
} {1 91 92 3 93 5}
do_test join6-3.2 {
  execsql {
    SELECT * FROM t1 JOIN t2 NATURAL JOIN t3;
  }
} {1 91 92 3 92 93 5}
do_test join6-3.3 {
  execsql {
    SELECT * FROM t1 JOIN t2 USING(y) NATURAL JOIN t3;
  }
} {1 91 92 3 93 5}
do_test join6-3.4 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 JOIN t3 USING(x,z);
  }
} {1 91 92 3 93 5}
do_test join6-3.5 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 JOIN t3 USING(x);
  }
} {1 91 92 3 93 5 93}
do_test join6-3.6 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 JOIN t3 USING(z);
  }
} {1 91 92 3 93 5 91 2 93 94 4 95 6 99}

do_test join6-4.1 {
  execsql {
    SELECT * FROM
       (SELECT 1 AS a, 91 AS x, 92 AS y UNION SELECT 2, 93, 94)
       NATURAL JOIN t2 NATURAL JOIN t3
  }
} {1 91 92 3 93 5}
do_test join6-4.2 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN
       (SELECT 3 AS b, 92 AS y, 93 AS z UNION SELECT 4, 94, 95)
       NATURAL JOIN t3
  }
} {1 91 92 3 93 5}
do_test join6-4.3 {
  execsql {
    SELECT * FROM t1 NATURAL JOIN t2 NATURAL JOIN
       (SELECT 5 AS c, 91 AS x, 93 AS z UNION SELECT 6, 99, 95)
  }
} {1 91 92 3 93 5}











finish_test

# 2009 December 16
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [31338dca7e] has been
# fixed.  Ticket [31338dca7e] demonstrates problems with the OR-clause
# optimization in joins where the WHERE clause is of the form
#
#     (x AND y) OR z
#
# And the x and y subterms from from different tables of the join.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test tkt-31338-1.1 {
  db eval {
    CREATE TABLE t1(x);
    CREATE TABLE t2(y);
    INSERT INTO t1 VALUES(111);
    INSERT INTO t1 VALUES(222);
    INSERT INTO t2 VALUES(333);
    INSERT INTO t2 VALUES(444);
    SELECT * FROM t1, t2
     WHERE (x=111 AND y!=444) OR x=222
     ORDER BY x, y;
  }
} {111 333 222 333 222 444}

do_test tkt-31338-1.2 {
  db eval {
    CREATE INDEX t1x ON t1(x);
    SELECT * FROM t1, t2
     WHERE (x=111 AND y!=444) OR x=222
     ORDER BY x, y;
  }
} {111 333 222 333 222 444}

do_test tkt-31338-2.1 {
  db eval {
    CREATE TABLE t3(v,w);
    CREATE TABLE t4(x,y);
    CREATE TABLE t5(z);
    INSERT INTO t3 VALUES(111,222);
    INSERT INTO t3 VALUES(333,444);
    INSERT INTO t4 VALUES(222,333);
    INSERT INTO t4 VALUES(444,555);
    INSERT INTO t5 VALUES(888);
    INSERT INTO t5 VALUES(999);
    
    SELECT * FROM t3, t4, t5
     WHERE (v=111 AND x=w AND z!=999) OR (v=333 AND x=444)
     ORDER BY v, w, x, y, z;
  }
} {111 222 222 333 888 333 444 444 555 888 333 444 444 555 999}

do_test tkt-31338-2.2 {
  db eval {
   CREATE INDEX t3v ON t3(v);
   CREATE INDEX t4x ON t4(x);
    SELECT * FROM t3, t4, t5
     WHERE (v=111 AND x=w AND z!=999) OR (v=333 AND x=444)
     ORDER BY v, w, x, y, z;
  }
} {111 222 222 333 888 333 444 444 555 888 333 444 444 555 999}


finish_test

# 2009 December 8
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# Verify that we can create zero-length tables.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test tkt-78e04-1.0 {
  execsql {
    CREATE TABLE ""("" UNIQUE);
    CREATE TABLE t2(x);
    INSERT INTO "" VALUES(1);
    INSERT INTO t2 VALUES(2);
    SELECT * FROM "", t2;
  }
} {1 2}
do_test tkt-78e04-1.1 {
  catchsql {
    INSERT INTO "" VALUES(1);
  }
} {1 {column  is not unique}}
do_test tkt-78e04-1.2 {
  execsql {
    PRAGMA table_info("");
  }
} {0 {} {} 0 {} 0}
do_test tkt-78e04-1.3 {
  execsql {
    CREATE INDEX i1 ON ""("" COLLATE nocase);
  }
} {}
do_test tkt-78e04-1.4 {
  execsql {
    EXPLAIN QUERY PLAN SELECT * FROM "" WHERE "" LIKE 'abc%';
  }
} {0 0 {TABLE }}
do_test tkt-78e04-1.5 {
  execsql {
    DROP TABLE "";
    SELECT name FROM sqlite_master;
  }
} {t2}

do_test tkt-78e04-2.1 {
  execsql {
    CREATE INDEX "" ON t2(x);
    EXPLAIN QUERY PLAN SELECT * FROM t2 WHERE x=5;
  }
} {0 0 {TABLE t2 WITH INDEX }}
do_test tkt-78e04-2.2 {
  execsql {
    DROP INDEX "";
    EXPLAIN QUERY PLAN SELECT * FROM t2 WHERE x=2;
  }
} {0 0 {TABLE t2}}

finish_test

# 2009 September 2
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [d82e3f3721] has been
# fixed.  
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test tkt-d82e3-1.1 {
  db eval {
    CREATE TABLE t1(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t1 VALUES(null,'abc');
    INSERT INTO t1 VALUES(null,'def');
    DELETE FROM t1;
    INSERT INTO t1 VALUES(null,'ghi');
    SELECT * FROM t1;
  }
} {3 ghi}
do_test tkt-d82e3-1.2 {
  db eval {
    CREATE TEMP TABLE t2(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t2 VALUES(null,'jkl');
    INSERT INTO t2 VALUES(null,'mno');
    DELETE FROM t2;
    INSERT INTO t2 VALUES(null,'pqr');
    SELECT * FROM t2;
  }
} {3 pqr}
do_test tkt-d82e3-1.3 {
  db eval {
    SELECT 'main', * FROM main.sqlite_sequence
    UNION ALL
    SELECT 'temp', * FROM temp.sqlite_sequence
    ORDER BY 2
  }
} {main t1 3 temp t2 3}
do_test tkt-d82e3-1.4 {
  db eval {
    VACUUM;
    SELECT 'main', * FROM main.sqlite_sequence
    UNION ALL
    SELECT 'temp', * FROM temp.sqlite_sequence
    ORDER BY 2
  }
} {main t1 3 temp t2 3}

sqlite3 db2 test.db
do_test tkt-d82e3-2.1 {
  db eval {
    CREATE TEMP TABLE t3(x);
    INSERT INTO t3 VALUES(1);
  }
  db2 eval {
    CREATE TABLE t3(y,z);
    INSERT INTO t3 VALUES(8,9);
  }
  db eval {
    SELECT * FROM temp.t3 JOIN main.t3;
  }
} {1 8 9}
do_test tkt-d82e3-2.2 {
  db eval {
    VACUUM;
    SELECT * FROM temp.t3 JOIN main.t3;
  }
} {1 8 9}
db2 close

finish_test

# 2009 September 2
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket [d82e3f3721] has been
# fixed.  
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test tkt-d82e3-1.1 {
  db eval {
    CREATE TABLE t1(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t1 VALUES(null,'abc');
    INSERT INTO t1 VALUES(null,'def');
    DELETE FROM t1;
    INSERT INTO t1 VALUES(null,'ghi');
    SELECT * FROM t1;
  }
} {3 ghi}
do_test tkt-d82e3-1.2 {
  db eval {
    CREATE TEMP TABLE t2(a INTEGER PRIMARY KEY AUTOINCREMENT, b);
    INSERT INTO t2 VALUES(null,'jkl');
    INSERT INTO t2 VALUES(null,'mno');
    DELETE FROM t2;
    INSERT INTO t2 VALUES(null,'pqr');
    SELECT * FROM t2;
  }
} {3 pqr}
do_test tkt-d82e3-1.3 {
  db eval {
    SELECT 'main', * FROM main.sqlite_sequence
    UNION ALL
    SELECT 'temp', * FROM temp.sqlite_sequence
    ORDER BY 2
  }
} {main t1 3 temp t2 3}
do_test tkt-d82e3-1.4 {
  db eval {
    VACUUM;
    SELECT 'main', * FROM main.sqlite_sequence
    UNION ALL
    SELECT 'temp', * FROM temp.sqlite_sequence
    ORDER BY 2
  }
} {main t1 3 temp t2 3}

sqlite3 db2 test.db
do_test tkt-d82e3-2.1 {
  db eval {
    CREATE TEMP TABLE t3(x);
    INSERT INTO t3 VALUES(1);
  }
  db2 eval {
    CREATE TABLE t3(y,z);
    INSERT INTO t3 VALUES(8,9);
  }
  db eval {
    SELECT * FROM temp.t3 JOIN main.t3;
  }
} {1 8 9}
do_test tkt-d82e3-2.2 {
  db eval {
    VACUUM;
    SELECT * FROM temp.t3 JOIN main.t3;
  }
} {1 8 9}

finish_test

    INSERT INTO t4 VALUES(378678316.5, 'his', 'Alpine');
    INSERT INTO t4 VALUES('from', 'of', 'all');
    INSERT INTO t4 VALUES(0938446095, 'same', NULL);
    INSERT INTO t4 VALUES(0938446095, 'Alpine', NULL);
    INSERT INTO t4 VALUES('his', 'of', 378678316.5);
    INSERT INTO t4 VALUES(271.2019091, 'viewed', 3282306647);
    INSERT INTO t4 VALUES('hills', 'all', 'peak');




    COMMIT;
  }
} {}

catch {unset results}
catch {unset A}
catch {unset B}
................................................................................
193  { SELECT * FROM t3, t4 WHERE c >= g OR 'writings' >= c AND b = 'all' }
194  { SELECT * FROM t3, t4 WHERE 'remarkably' < g }
195  { SELECT * FROM t3, t4 WHERE a BETWEEN 'or' AND 'paintings' AND g <= f }
196  { SELECT * FROM t3, t4 WHERE 0938446095 > b OR g <= a OR h > b }
197  { SELECT * FROM t3, t4 WHERE g = 2643383279 AND f = g }
198  { SELECT * FROM t3, t4 WHERE g < 8979323846 }
199  { SELECT * FROM t3, t4 WHERE 'are' <= b }









  } {
    do_test where8-4.$A.$B.1 {
      unset -nocomplain R
      set R [execsql $sql]
      if {![info exists results($B)]} {
        set results($B) $R

    INSERT INTO t4 VALUES(378678316.5, 'his', 'Alpine');
    INSERT INTO t4 VALUES('from', 'of', 'all');
    INSERT INTO t4 VALUES(0938446095, 'same', NULL);
    INSERT INTO t4 VALUES(0938446095, 'Alpine', NULL);
    INSERT INTO t4 VALUES('his', 'of', 378678316.5);
    INSERT INTO t4 VALUES(271.2019091, 'viewed', 3282306647);
    INSERT INTO t4 VALUES('hills', 'all', 'peak');
    CREATE TABLE t5(s);
    INSERT INTO t5 VALUES('tab-t5');
    CREATE TABLE t6(t);
    INSERT INTO t6 VALUES(123456);
    COMMIT;
  }
} {}

catch {unset results}
catch {unset A}
catch {unset B}
................................................................................
193  { SELECT * FROM t3, t4 WHERE c >= g OR 'writings' >= c AND b = 'all' }
194  { SELECT * FROM t3, t4 WHERE 'remarkably' < g }
195  { SELECT * FROM t3, t4 WHERE a BETWEEN 'or' AND 'paintings' AND g <= f }
196  { SELECT * FROM t3, t4 WHERE 0938446095 > b OR g <= a OR h > b }
197  { SELECT * FROM t3, t4 WHERE g = 2643383279 AND f = g }
198  { SELECT * FROM t3, t4 WHERE g < 8979323846 }
199  { SELECT * FROM t3, t4 WHERE 'are' <= b }
200  { SELECT * FROM t3, t4 WHERE (a=1415926535 AND f=8628034825)
                               OR (a=6939937510 AND f=2643383279) }
201  { SELECT * FROM t3, t4, t5, t6
        WHERE (a=1415926535 AND f=8628034825 AND s!='hello' AND t!=5)
           OR (a=6939937510 AND f=2643383279 AND s='tab-t5' AND t=123456) }
202  { SELECT * FROM t3, t4, t5, t6
        WHERE (a=1415926535 AND f=8628034825 AND s!='hello' AND t==5)
           OR (a=6939937510 AND f=2643383279 AND s='tab-t5' AND t!=123456) }

  } {
    do_test where8-4.$A.$B.1 {
      unset -nocomplain R
      set R [execsql $sql]
      if {![info exists results($B)]} {
        set results($B) $R