SQLite

** This file contains the C functions that implement date and time
** functions for SQLite.  
**
** There is only one exported symbol in this file - the function
** sqlite3RegisterDateTimeFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: date.c,v 1.25 2004/05/26 16:54:42 drh Exp $
**
** NOTES:
**
** SQLite processes all times and dates as Julian Day numbers.  The
** dates and times are stored as the number of days since noon
** in Greenwich on November 24, 4714 B.C. according to the Gregorian
** calendar system.

** the resulting time into the DateTime structure p.  Return 0
** on success and 1 if there are any errors.
*/
static int isDate(int argc, sqlite3_value **argv, DateTime *p){
  int i;
  if( argc==0 ) return 1;
  if( SQLITE3_NULL==sqlite3_value_type(argv[0]) || 
      parseDateOrTime(sqlite3_value_data(argv[0]), p) ) return 1;
  for(i=1; i<argc; i++){
    if( SQLITE3_NULL==sqlite3_value_type(argv[i]) || 
        parseModifier(sqlite3_value_data(argv[i]), p) ) return 1;
  }
  return 0;
}


/*
** The following routines implement the various date and time functions

  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  DateTime x;
  int n, i, j;
  char *z;
  const char *zFmt = sqlite3_value_data(argv[0]);
  char zBuf[100];
  if( zFmt==0 || isDate(argc-1, argv+1, &x) ) return;
  for(i=0, n=1; zFmt[i]; i++, n++){
    if( zFmt[i]=='%' ){
      switch( zFmt[i+1] ){
        case 'd':
        case 'H':

** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.57 2004/05/26 16:54:43 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"
#include "vdbeInt.h"

    case SQLITE3_BLOB:
    case SQLITE3_INTEGER:
    case SQLITE3_FLOAT: {
      sqlite3_result_int32(context, sqlite3_value_bytes(argv[0]));
      break;
    }
    case SQLITE3_TEXT: {
      const char *z = sqlite3_value_data(argv[0]);
      for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
      sqlite3_result_int32(context, len);
      break;
    }
    default: {
      sqlite3_result_null(context);
      break;
    }
  }
}

/*
** Implementation of the abs() function
*/
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  const char *z;
  assert( argc==1 );
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE3_INTEGER: {
      sqlite3_result_int64(context, -sqlite3_value_int(argv[0]));
      break;
    }
    case SQLITE3_NULL: {
      sqlite3_result_null(context);
      break;
    }
    default: {
      sqlite3_result_double(context, -sqlite3_value_float(argv[0]));
      break;
    }
  }
}

/*
** Implementation of the substr() function
*/
static void substrFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *z;
  const char *z2;
  int i;
  int p1, p2, len;

  assert( argc==3 );
  z = sqlite3_value_data(argv[0]);
  if( z==0 ) return;
  p1 = sqlite3_value_int(argv[1]);
  p2 = sqlite3_value_int(argv[2]);
  for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
  if( p1<0 ){
    p1 += len;
    if( p1<0 ){

  if( argc==2 ){
    if( SQLITE3_NULL==sqlite3_value_type(argv[1]) ) return;
    n = sqlite3_value_int(argv[1]);
    if( n>30 ) n = 30;
    if( n<0 ) n = 0;
  }
  if( SQLITE3_NULL==sqlite3_value_type(argv[0]) ) return;
  r = sqlite3_value_float(argv[0]);
  sprintf(zBuf,"%.*f",n,r);
  sqlite3_result_text(context, zBuf, -1, 1);
}

/*
** Implementation of the upper() and lower() SQL functions.
*/
static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  char *z;
  int i;
  if( argc<1 || SQLITE3_NULL==sqlite3_value_type(argv[0]) ) return;
  z = sqliteMalloc(sqlite3_value_bytes(argv[0]));
  if( z==0 ) return;
  strcpy(z, sqlite3_value_data(argv[0]));
  for(i=0; z[i]; i++){
    if( islower(z[i]) ) z[i] = toupper(z[i]);
  }
  sqlite3_result_text(context, z, -1, 1);
  sqliteFree(z);
}
static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  char *z;
  int i;
  if( argc<1 || SQLITE3_NULL==sqlite3_value_type(argv[0]) ) return;
  z = sqliteMalloc(sqlite3_value_bytes(argv[0]));
  if( z==0 ) return;
  strcpy(z, sqlite3_value_data(argv[0]));
  for(i=0; z[i]; i++){
    if( isupper(z[i]) ) z[i] = tolower(z[i]);
  }
  sqlite3_result_text(context, z, -1, 1);
  sqliteFree(z);
}

** is implemented as like(A,B).
*/
static void likeFunc(
  sqlite3_context *context, 
  int argc, 
  sqlite3_value **argv
){
  const unsigned char *zA = sqlite3_value_data(argv[0]);
  const unsigned char *zB = sqlite3_value_data(argv[1]);
  if( zA && zB ){
    sqlite3_result_int32(context, sqlite3LikeCompare(zA, zB));
  }
}

/*
** Implementation of the glob() SQL function.  This function implements
** the build-in GLOB operator.  The first argument to the function is the
** string and the second argument is the pattern.  So, the SQL statements:
**
**       A GLOB B
**
** is implemented as glob(A,B).
*/
static void globFunc(sqlite3_context *context, int arg, sqlite3_value **argv){
  const unsigned char *zA = sqlite3_value_data(argv[0]);
  const unsigned char *zB = sqlite3_value_data(argv[1]);
  if( zA && zB ){
    sqlite3_result_int32(context, sqlite3GlobCompare(zA, zB));
  }
}

/*
** Implementation of the NULLIF(x,y) function.  The result is the first

** Implementation of the QUOTE() function.  This function takes a single
** argument.  If the argument is numeric, the return value is the same as
** the argument.  If the argument is NULL, the return value is the string
** "NULL".  Otherwise, the argument is enclosed in single quotes with
** single-quote escapes.
*/
static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  const char *zArg = sqlite3_value_data(argv[0]);
  if( argc<1 ) return;
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE3_NULL: {
      sqlite3_result_text(context, "NULL", 4, 0);
      break;
    }
    case SQLITE3_INTEGER:
    case SQLITE3_FLOAT: {
      sqlite3_result(context, argv[0]);
      break;
    }
    case SQLITE3_BLOB:  /*** FIX ME.  Use a BLOB encoding ***/
    case SQLITE3_TEXT: {
      int i,j,n;
      const char *zArg = sqlite3_value_data(argv[0]);
      char *z;

      for(i=n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
      z = sqliteMalloc( i+n+3 );
      if( z==0 ) return;
      z[0] = '\'';
      for(i=0, j=1; zArg[i]; i++){

    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
    0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
    1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
  };
  assert( argc==1 );
  zIn = sqlite3_value_data(argv[0]);
  for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
  if( zIn[i] ){
    zResult[0] = toupper(zIn[i]);
    for(j=1; j<4 && zIn[i]; i++){
      int code = iCode[zIn[i]&0x7f];
      if( code>0 ){
        zResult[j++] = code + '0';

/*
** Routines used to compute the sum or average.
*/
static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  SumCtx *p;
  if( argc<1 ) return;
  p = sqlite3_get_context(context, sizeof(*p));
  if( p && SQLITE3_NULL!=sqlite3_value_type(argv[0]) ){
    p->sum += sqlite3_value_float(argv[0]);
    p->cnt++;
  }
}
static void sumFinalize(sqlite3_context *context){
  SumCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  sqlite3_result_double(context, p ? p->sum : 0.0);
}
static void avgFinalize(sqlite3_context *context){
  SumCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  if( p && p->cnt>0 ){
    sqlite3_result_double(context, p->sum/(double)p->cnt);
  }
}

/*
** An instance of the following structure holds the context of a

};

/*
** Routines to implement the count() aggregate function.
*/
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  CountCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  if( (argc==0 || SQLITE3_NULL!=sqlite3_value_type(argv[0])) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite3_context *context){
  CountCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  sqlite3_result_int32(context, p ? p->n : 0);
}

/*
** This function tracks state information for the min() and max()
** aggregate functions.
*/
typedef struct MinMaxCtx MinMaxCtx;
struct MinMaxCtx {
  char *z;         /* The best so far */
  char zBuf[28];   /* Space that can be used for storage */
};

/*
** Routines to implement min() and max() aggregate functions.
*/
static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  int max = 0;
  int cmp = 0;
  Mem *pArg  = (Mem *)argv[0];
  Mem *pBest = (Mem *)sqlite3_get_context(context, sizeof(*pBest));

  if( SQLITE3_NULL==sqlite3_value_type(argv[0]) ) return;

  if( pBest->flags ){
    /* This step function is used for both the min() and max() aggregates,
    ** the only difference between the two being that the sense of the
    ** comparison is inverted. For the max() aggregate, the

    }
  }else{
    sqlite3VdbeMemCopy(pBest, pArg);
  }
}
static void minMaxFinalize(sqlite3_context *context){
  sqlite3_value *pRes;
  pRes = (sqlite3_value *)sqlite3_get_context(context, sizeof(Mem));
  if( pRes->flags ){
    sqlite3_result(context, pRes);
  }
}

/*
** This function registered all of the above C functions as SQL

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: legacy.c,v 1.2 2004/05/26 02:04:57 danielk1977 Exp $
*/

#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*

            azCols[i] = (char *)sqlite3_column_name(pStmt, i);
          }
          nCallback++;
        }
        if( rc==SQLITE_ROW ){
          azVals = &azCols[nCol];
          for(i=0; i<nCol; i++){
            azVals[i] = (char *)sqlite3_column_data(pStmt, i);
          }
        }
        if( xCallback(pArg, nCol, azVals, azCols) ){
          rc = SQLITE_ABORT;
          goto exec_out;
        }
      }

    }
  }else if( pzErrMsg ){
    *pzErrMsg = 0;
  }

  return rc;
}

** During testing, the special md5sum() aggregate function is available.
** inside SQLite.  The following routines implement that function.
*/
static void md5step(sqlite3_context *context, int argc, sqlite3_value **argv){
  MD5Context *p;
  int i;
  if( argc<1 ) return;
  p = sqlite3_get_context(context, sizeof(*p));
  if( p==0 ) return;
  if( sqlite3_aggregate_count(context)==1 ){
    MD5Init(p);
  }
  for(i=0; i<argc; i++){
    const char *zData = sqlite3_value_data(argv[i]);
    if( zData ){
      MD5Update(p, zData, strlen(zData));
    }
  }
}
static void md5finalize(sqlite3_context *context){
  MD5Context *p;
  unsigned char digest[16];
  char zBuf[33];
  p = sqlite3_get_context(context, sizeof(*p));
  MD5Final(digest,p);
  DigestToBase16(digest, zBuf);
  sqlite3_result_text(context, zBuf, -1, 1);
}
void Md5_Register(sqlite *db){
  sqlite3_create_function(db, "md5sum", -1, 0, 0, 0, 0, md5step, md5finalize);
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.81 2004/05/26 16:54:44 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.

/*
** Call this routine to free the memory that sqlite3_get_table() allocated.
*/
void sqlite3_free_table(char **result);

/*
** The following routines are wrappers around sqlite3_exec() and
** sqlite3_get_table().  The only difference between the routines that
** follow and the originals is that the second argument to the 
** routines that follow is really a printf()-style format
** string describing the SQL to be executed.  Arguments to the format


** string appear at the end of the argument list.
**
** All of the usual printf formatting options apply.  In addition, there
** is a "%q" option.  %q 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.

**
**      INSERT INTO table1 VALUES('It's a happy day!');
**
** 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.
*/
int sqlite3_exec_printf(
  sqlite*,                      /* An open database */
  const char *sqlFormat,        /* printf-style format string for the SQL */
  sqlite_callback,              /* Callback function */
  void *,                       /* 1st argument to callback function */
  char **errmsg,                /* Error msg written here */
  ...                           /* Arguments to the format string. */
);
int sqlite3_exec_vprintf(
  sqlite*,                      /* An open database */
  const char *sqlFormat,        /* printf-style format string for the SQL */
  sqlite_callback,              /* Callback function */
  void *,                       /* 1st argument to callback function */
  char **errmsg,                /* Error msg written here */
  va_list ap                    /* Arguments to the format string. */
);
int sqlite3_get_table_printf(
  sqlite*,               /* An open database */
  const char *sqlFormat, /* printf-style format string for the SQL */
  char ***resultp,       /* Result written to a char *[]  that this points to */
  int *nrow,             /* Number of result rows written here */
  int *ncolumn,          /* Number of result columns written here */
  char **errmsg,         /* Error msg written here */
  ...                    /* Arguments to the format string */
);
int sqlite3_get_table_vprintf(
  sqlite*,               /* An open database */
  const char *sqlFormat, /* printf-style format string for the SQL */
  char ***resultp,       /* Result written to a char *[]  that this points to */
  int *nrow,             /* Number of result rows written here */
  int *ncolumn,          /* Number of result columns written here */
  char **errmsg,         /* Error msg written here */
  va_list ap             /* Arguments to the format string */
);
char *sqlite3_mprintf(const char*,...);
char *sqlite3_vmprintf(const char*, va_list);

/*
** Windows systems should call this routine to free memory that
** is returned in the in the errmsg parameter of sqlite3_open() when
** SQLite is a DLL.  For some reason, it does not work to call free()
** directly.
*/
void sqlite3_freemem(void *p);

/*
** Windows systems need functions to call to return the sqlite3_version
** and sqlite3_encoding strings.
*/
const char *sqlite3_libversion(void);
const char *sqlite3_libencoding(void);

** Registering a NULL function disables the callback.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
void *sqlite3_commit_hook(sqlite*, int(*)(void*), void*);

/*
** Open an encrypted SQLite database.  If pKey==0 or nKey==0, this routine
** is the same as sqlite3_open().
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
sqlite *sqlite3_open_encrypted(
  const char *zFilename,   /* Name of the encrypted database */
  const void *pKey,        /* Pointer to the key */
  int nKey,                /* Number of bytes in the key */
  int *pErrcode,           /* Write error code here */
  char **pzErrmsg          /* Write error message here */
);

/*
** Change the key on an open database.  If the current database is not
** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
** database is decrypted.
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
int sqlite_rekey(
  sqlite *db,                    /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** Encode a binary buffer "in" of size n bytes so that it contains
** no instances of characters '\'' or '\000'.  The output is 
** null-terminated and can be used as a string value in an INSERT
** or UPDATE statement.  Use sqlite_decode_binary() to convert the
** string back into its original binary.
**
** The result is written into a preallocated output buffer "out".
** "out" must be able to hold at least 2 +(257*n)/254 bytes.
** In other words, the output will be expanded by as much as 3
** bytes for every 254 bytes of input plus 2 bytes of fixed overhead.
** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.)
**
** The return value is the number of characters in the encoded
** string, excluding the "\000" terminator.
**
** If out==NULL then no output is generated but the routine still returns
** the number of characters that would have been generated if out had
** not been NULL.
*/
int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out);

/*
** Decode the string "in" into binary data and write it into "out".
** This routine reverses the encoding created by sqlite_encode_binary().
** The output will always be a few bytes less than the input.  The number
** of bytes of output is returned.  If the input is not a well-formed
** encoding, -1 is returned.
**
** The "in" and "out" parameters may point to the same buffer in order
** to decode a string in place.
*/
int sqlite_decode_binary(const unsigned char *in, unsigned char *out);

/*
** Open the sqlite database file "filename", where "filename" is UTF-8

** encoded. An sqlite3* handle is returned in *ppDb, even if an error 
** occurs. If the database is opened (or created) successfully, then 
** SQLITE_OK is returned. Otherwise an error code is returned and the
** sqlite3_errmsg() function may be used to obtain an English language
** explanation of the error.
**
** If the database file does not exist, then a new database is created

** using UTF-8 text encoding.
**
** Whether or not an error occurs when it is opened, resources associated
** with the sqlite3* handle should be released by passing it to
** sqlite3_close() when it is no longer required.
*/
int sqlite3_open(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  const char **args       /* Null terminated array of option strings */
);

/*
** Open the sqlite database file "filename", where "filename" is native
** byte order UTF-16 encoded. An sqlite3* handle is returned in *ppDb, even
** if an error occurs. If the database is opened (or created) successfully,
** then SQLITE_OK is returned. Otherwise an error code is returned and the
** sqlite3_errmsg() function may be used to obtain an English language
** explanation of the error.
**
** If the database file does not exist, then a new database is created
** using UTF-16 text encoding in the machines native byte order.
**
** Whether or not an error occurs when it is opened, resources associated
** with the sqlite3* handle should be released by passing it to
** sqlite3_close() when it is no longer required.
*/
int sqlite3_open16(
  const void *filename,   /* Database filename (UTF-16) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  const char **args       /* Null terminated array of option strings */
);

/*

  sqlite3 *db,            /* Database handle */
  const void *zSql,       /* SQL statement, UTF-16 encoded */
  int nBytes,             /* Length of zSql in bytes. */
  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
);






























/*
** Return the number of columns in the result set returned by the compiled
** SQL 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);

/*
** The first parameter is a compiled SQL statement. This function returns
** the column heading for the Nth column of that statement, where N is the
** second function parameter. The string returned is UTF-8 encoded.

*/
const char *sqlite3_column_name(sqlite3_stmt*,int);

/*
** The first parameter is a compiled SQL statement. This function returns
** the column heading for the Nth column of that statement, where N is the
** second function parameter. The string returned is UTF-16 encoded.
*/
const void *sqlite3_column_name16(sqlite3_stmt*,int);

/*
** The first parameter is a compiled SQL statement. If this statement
** is a SELECT statement, the Nth column of the returned result set 
** of the SELECT is a table column then the declared type of the table
** column is returned. If the Nth column of the result set is not at table

** The first parameter is a compiled SQL statement. If this statement
** is a SELECT statement, the Nth column of the returned result set 
** of the SELECT is a table column then the declared type of the table
** column is returned. If the Nth column of the result set is not at table
** column, then a NULL pointer is returned. The returned string is always
** UTF-16 encoded. For example, in the database schema:
**
** CREATE TABLE t1(c1 VARINT);
**
** And the following statement compiled:
**
** SELECT c1 + 1, 0 FROM t1;
**
** Then 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).
*/
const void *sqlite3_column_decltype16(sqlite3_stmt*,int);

/*
** This routine is used to bind a 32-bit integer value to a variable
** in an SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously
** obtained from a call to sqlite3_prepare(). The second parameter "i"
** determines the parameter to bind the value "iValue" to.
*/
int sqlite3_bind_int32(sqlite3_stmt*, int i, int iValue);

/*
** This routine is used to bind a 64-bit integer value to a variable
** in an SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously
** obtained from a call to sqlite3_prepare(). The second parameter "i"
** determines the parameter to bind the value "iValue" to.
*/
int sqlite3_bind_int64(sqlite3_stmt*, int i, long long int iValue);

/*
** This routine is used to bind a real (floating point) value to a variable
** in an SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously obtained
** from a call to sqlite3_prepare(). The second parameter "i" determines
** the parameter to bind the value "iValue" to. Internally, SQLite will
** manipulate the value as a 64-bit IEEE float.
*/
int sqlite3_bind_double(sqlite3_stmt*, int i, double iValue);

/*
** This routine is used to bind a NULL value to a variable in an SQL
** statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously obtained
** from a call to sqlite3_prepare(). The second parameter "i" determines
** the parameter to bind the NULL value to.
*/
int sqlite3_bind_null(sqlite3_stmt*, int i);

/*
** This routine is used to bind a UTF-8 string value to a variable in an
** SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously obtained
** from a call to sqlite3_prepare(). The second parameter "i" determines
** the parameter to bind the value to. Parameter three "z" is a pointer
** to the UTF-8 string. 
**
** The fourth "n" parameter is the number of bytes (not characters) in the
** string pointed to by "z". "n" may or may not include any nul terminator
** character. If "n" is less than zero, then SQLite assumes that "z" is
** a nul terminated string.
**
** If paramater "eCopy" is true, then SQLite makes a copy of the string
** pointed to by "z". If "eCopy" is false, then SQLite stores a pointer to
** the original string data. In this case the caller must ensure that the
** string data remains stable until after the SQL statement has been
** finalised or another value bound to variable "i".
*/
int sqlite3_bind_text(sqlite3_stmt*, int i, const char* z, int n, int eCopy);

/*
** This routine is used to bind a UTF-16 string value to a variable in an
** SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously obtained
** from a call to sqlite3_prepare(). The second parameter "i" determines
** the parameter to bind the value to. Parameter three "z" is a pointer to
** the UTF-16 string. If the string does not begin with a byte-order-mark,
** it is assumed to be encoded in the native byte order of the machine.
**
** The fourth "n" parameter is the number of bytes (not characters) in the
** string pointed to by "z". "n" may or may not include any nul terminator
** character. If "n" is less than zero, then SQLite assumes that "z" is
** terminated by a pair of 0x00 characters.
**
** If paramater "eCopy" is true, then SQLite makes a copy of the string
** pointed to by "z". If "eCopy" is false, then SQLite stores a pointer to
** the original string data. In this case the caller must ensure that the
** string data remains stable until after the SQL statement has been
** finalised or another value bound to variable "i".
*/
int sqlite3_bind_text16(sqlite3_stmt*, int i, const void *z, int, int eCopy);

/*
** This routine is used to bind a blob value to a variable in an
** SQL statement compiled by sqlite3_prepare(). See comments for
** sqlite3_prepare() for more details on SQL statement variables.
**
** The first argument is a pointer to an SQL statement previously obtained
** from a call to sqlite3_prepare(). The second parameter "i" determines
** the parameter to bind the value to. Parameter three "z" is a pointer to
** the blob of data.
**
** The fourth "n" parameter is the number of bytes in the blob pointed to
** by "z". "n" may not be less than zero.
**
** If paramater "eCopy" is true, then SQLite makes a copy of the blob
** pointed to by "z". If "eCopy" is false, then SQLite stores a pointer to
** the original blob data. In this case the caller must ensure that the
** blob data remains stable until after the SQL statement has been
** finalised or another value bound to variable "i".
*/
int sqlite3_bind_blob(sqlite3_stmt*, int i, const void *z, int n, int eCopy);

/* 
** After an SQL query has been compiled with a call to either
** sqlite3_prepare() or sqlite3_prepare16(), then this function must be
** called one or more times to execute the statement.
**
** The return value will be either SQLITE_BUSY, SQLITE_DONE, 
** SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.

** will return the same value as the sqlite3_column_count() function.
** After sqlite3_step() has returned an SQLITE_DONE, SQLITE_BUSY or
** error code, or before sqlite3_step() has been called on a 
** compiled SQL statement, this routine returns zero.
*/
int sqlite3_data_count(sqlite3_stmt *pStmt);





#define SQLITE3_INTEGER  1
#define SQLITE3_FLOAT    2
#define SQLITE3_TEXT     3
#define SQLITE3_BLOB     4
#define SQLITE3_NULL     5

/*
** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the type of the Nth column of the current row, where
** N is the second function parameter.
**
** The value type is one of SQLITE3_INTEGER, SQLITE3_FLOAT, SQLITE3_TEXT,
** SQLITE3_BLOB and SQLITE3_NULL.
*/
int sqlite3_column_type(sqlite3_stmt *pStmt, int i);

/*
** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the value of the Nth column of the current row, where
** N is the second function parameter.
**
** The value returned depends on the type of the SQL column value, as
** returned by sqlite3_column_type():
**
** SQLITE3_NULL      A Null pointer.
** SQLITE3_INTEGER   String representation of the integer, UTF-8 encoded.
** SQLITE3_FLOAT     String representation of the real, UTF-8 encoded.
** SQLITE3_TEXT      The string UTF-8 encoded.
** SQLITE3_BLOB      A pointer to the blob of data.
*/
const unsigned char *sqlite3_column_data(sqlite3_stmt*,int);

/*
** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the value of the Nth column of the current row, where
** N is the second function parameter.
**
** The value returned depends on the type of the SQL column value, as
** returned by sqlite3_column_type():
**
** SQLITE3_NULL      A Null pointer.
** SQLITE3_INTEGER   String representation of the integer, UTF-16 encoded.
** SQLITE3_FLOAT     String representation of the real, UTF-16 encoded.
** SQLITE3_TEXT      The string UTF-16 encoded.
** SQLITE3_BLOB      A pointer to the blob of data.
*/
const void *sqlite3_column_data16(sqlite3_stmt*,int);

/*


** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the length of the data in bytes returned by the
** sqlite3_column_data() routine for the same second parameter value.


**
** If sqlite3_column_data() returns a UTF-8 string, then the length
** returned by this function includes the nul terminator character at the
** end of the UTF-8 string.
*/
int sqlite3_column_bytes(sqlite3_stmt*,int);

/*

** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the length of the data in bytes returned by the
** sqlite3_column_data() routine for the same second parameter value.
**
** If sqlite3_column_data() returns a UTF-16 string, then the length
** returned by this function includes the nul terminator character (two
** bytes) at the end of the UTF-16 string.
*/
int sqlite3_column_bytes16(sqlite3_stmt *, int);













/*
** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the value of the Nth column of the current row, where
** N is the second function parameter as an integer.
**


** SQLITE3_NULL      0
** SQLITE3_INTEGER   The integer value.






** SQLITE3_FLOAT     The integer component of the real (2^63 if too large)

** SQLITE3_TEXT      Integer conversion of string, or 0
** SQLITE3_BLOB      0



*/





long long int sqlite3_column_int(sqlite3_stmt*,int);

/*
** The first parameter is a compiled SQL statement for which the most
** recent call to sqlite3_step() has returned SQLITE_ROW. This routine
** retrieves the value of the Nth column of the current row, where
** N is the second function parameter as an integer.
**
** SQLITE3_NULL      0.0
** SQLITE3_INTEGER   The value of the integer. Some rounding may occur.
** SQLITE3_FLOAT     The value of the float.
** SQLITE3_TEXT      Real number conversion of string, or 0.0
** SQLITE3_BLOB      0.0
*/
double sqlite3_column_float(sqlite3_stmt*,int);

/*
** The sqlite3_finalize() function is called to delete a compiled
** SQL statement obtained by a previous call to sqlite3_prepare()
** or sqlite3_prepare16(). 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 is returned. 

/*
** The next routine returns the number of calls to xStep for a particular
** aggregate function instance.  The current call to xStep counts so this
** routine always returns at least 1.
*/
int sqlite3_aggregate_count(sqlite3_context*);


/*
** Return the type of the sqlite3_value* passed as the first argument. 
** The type is one of SQLITE3_NULL, SQLITE3_INTEGER, SQLITE3_FLOAT,
** SQLITE3_TEXT or SQLITE3_BLOB.
*/
int sqlite3_value_type(sqlite3_value*);

/*
** Return the value of the sqlite3_value* passed as the first argument.
** The value returned depends on the type of the value, as returned by
** sqlite3_value_type():
**
** SQLITE3_NULL      A Null pointer.
** SQLITE3_INTEGER   String representation of the integer, UTF-8 encoded.
** SQLITE3_FLOAT     String representation of the real, UTF-8 encoded.
** SQLITE3_TEXT      The string UTF-8 encoded.
** SQLITE3_BLOB      A pointer to the blob of data.
*/ 
const unsigned char *sqlite3_value_data(sqlite3_value*);

/*
** Return the number of bytes in the string or blob returned by a call
** to sqlite3_value_data() on the same sqlite3_value* object.
*/
int sqlite3_value_bytes(sqlite3_value*);

/*
** Return the value of the sqlite3_value* passed as the first argument.
** The value returned depends on the type of the value, as returned by
** sqlite3_value_type():
**
** SQLITE3_NULL      A Null pointer.
** SQLITE3_INTEGER   String representation of the integer, UTF-16 encoded.
** SQLITE3_FLOAT     String representation of the real, UTF-16 encoded.
** SQLITE3_TEXT      The string UTF-16 encoded.
** SQLITE3_BLOB      A pointer to the blob of data.
*/ 
const void *sqlite3_value_data16(sqlite3_value*);

/*
** Return the number of bytes in the string or blob returned by a call
** to sqlite3_value_data16() on the same sqlite3_value* object.
*/
int sqlite3_value_bytes16(sqlite3_value*);

/*
** Return the value of the sqlite3_value* passed as the first argument.
** The value returned depends on the type of the value, as returned by
** sqlite3_value_type():
**
** SQLITE3_NULL      0
** SQLITE3_INTEGER   The integer value.
** SQLITE3_FLOAT     The integer component of the real (2^63 if too large)
** SQLITE3_TEXT      Integer conversion of string, or 0
** SQLITE3_BLOB      0
*/
long long int sqlite3_value_int(sqlite3_value*);

/*
** Return the value of the sqlite3_value* passed as the first argument.
** The value returned depends on the type of the value, as returned by
** sqlite3_value_type():
**
** SQLITE3_NULL      0.0
** SQLITE3_INTEGER   The value of the integer. Some rounding may occur.
** SQLITE3_FLOAT     The value of the float.
** SQLITE3_TEXT      Real number conversion of string, or 0.0
** SQLITE3_BLOB      0.0
*/
double sqlite3_value_float(sqlite3_value*);

/*
** Aggregate functions use the following routine to allocate
** a structure for storing their state.  The first time this routine
** is called for a particular aggregate, a new structure of size nBytes
** is allocated, zeroed, and returned.  On subsequent calls (for the
** same aggregate instance) the same buffer is returned.  The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** The buffer allocated is freed automatically by SQLite.
*/
void *sqlite3_get_context(sqlite3_context*, int nBytes);

/*
** The pUserData parameter to the sqlite3_create_function() and
** sqlite3_create_aggregate() routines used to register user functions
** is available to the implementation of the function using this
** call.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** The following three functions may be called from within a user-defined
** function callback or a user-defined aggregate finalizer callback. The
** result of the user-defined function or aggregate is set to the value of
** the second parameter. Any value previously set as the return value via
** an sqlite3_result_*() call is overwritten.
**
** The first parameter to each of these routines must be a copy of the
** sqlite3_context* pointer passed to the user-defined function or
** aggregate finalizer function.
*/
void sqlite3_result_int32(sqlite3_context*, int);
void sqlite3_result_int64(sqlite3_context*, long long int);
void sqlite3_result_double(sqlite3_context*, double);

/*
** This function may be called from within a user-defined function callback
** or a user-defined aggregate finalizer callback. The result of the
** user-defined function or aggregate is set to NULL.  Any value previously
** set as the return value via an sqlite3_result_*() call is overwritten.
**
** The parameter to this routine must be a copy of the sqlite3_context*
** pointer passed to the user-defined function or aggregate finalizer
** function.
*/
void sqlite3_result_null(sqlite3_context*);

/*
** The following two functions may be called from within a user-defined or
** a user-defined aggregate finalizer callback to return a text value. 
** The second parameter is a pointer to the string, encoded in UTF-8 
** for sqlite3_result_text() and UTF-16 (machine byte order) for
** sqlite3_result_text16(). 
**
** If the third parameter, n,  is positive, it is the number of bytes (not
** characters) in the string data. A negative n value indicates that the
** string may be read up to the nul terminator character.
**
** If the fourth parameter is non-zero, then a copy is made of the string.
** Otherwise, SQLite stores a pointer to the original string data.
**
** The first parameter to this routine must be a copy of the
** sqlite3_context* pointer passed to the user-defined function or
** aggregate finalizer function.
*/
void sqlite3_result_text(sqlite3_context*, const char*, int n, int eCopy);
void sqlite3_result_text16(sqlite3_context*, const void*, int n, int eCopy);

/*
** The following function may be called from within a user-defined or a
** user-defined aggregate finalizer callback to return a blob value.  The
** second parameter is a pointer to the blob of data. The third parameter
** is the number of bytes of data in the blob.
**
** If the fourth parameter is non-zero, then a copy is made of the blob.
** Otherwise, SQLite stores a pointer to the original blob data.
**
** The first parameter to this routine must be a copy of the
** sqlite3_context* pointer passed to the user-defined function or
** aggregate finalizer function.
*/
void sqlite3_result_blob(sqlite3_context*, const void*, int n, int eCopy);

/*
** These routines are used from within a user-defined or a user-defined
** aggregate finalizer callback to return an error. The second parameter
** is a pointer to a string describing the error, or NULL if no explanation
** is provided.
**
** The string should be encoded in UTF-8 for sqlite3_result_error() and
** UTF-16 (machine byte order) for sqlite3_result_error16().
**
** If not negative, the third parameter is the number of bytes (not
** characters) in the string passed as the second argument. If the third
** parameter is negative, then the string is read up to the first nul
** terminator character.
*/
void sqlite3_result_error(sqlite3_context*, const char*, int);
void sqlite3_result_error16(sqlite3_context*, const void*, int);

/*
** Copy a function parameter into the result of the function.
*/
void sqlite3_result(sqlite3_context*, sqlite3_value*);

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.72 2004/05/26 16:54:46 drh Exp $
*/
#ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */

#include "sqliteInt.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  Tcl_DStringInit(&cmd);
  Tcl_DStringAppend(&cmd, p->zScript, -1);
  for(i=0; i<argc; i++){
    if( SQLITE3_NULL==sqlite3_value_type(argv[i]) ){
      Tcl_DStringAppendElement(&cmd, "");
    }else{
      Tcl_DStringAppendElement(&cmd, sqlite3_value_data(argv[i]));
    }
  }
  rc = Tcl_Eval(p->interp, Tcl_DStringValue(&cmd));
  if( rc ){
    sqlite3_result_error(context, Tcl_GetStringResult(p->interp), -1); 
  }else{
    sqlite3_result_text(context, Tcl_GetStringResult(p->interp), -1, 1);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the printf() interface to SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.58 2004/05/26 13:27:00 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

** Implementation of the x_coalesce() function.
** Return the first argument non-NULL argument.
*/
static void ifnullFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  int i;
  for(i=0; i<argc; i++){
    if( SQLITE3_NULL!=sqlite3_value_type(argv[i]) ){
      sqlite3_result_text(context, sqlite3_value_data(argv[i]), -1, 1);
      break;
    }
  }
}

/*
** A structure into which to accumulate text.

  sqlite3_context *context, 
  int argc,  
  sqlite3_value **argv
){
  struct dstr x;
  memset(&x, 0, sizeof(x));
  sqlite3_exec((sqlite*)sqlite3_user_data(context),
      sqlite3_value_data(argv[0]),
      execFuncCallback, &x, 0);
  sqlite3_result_text(context, x.z, x.nUsed, 1);
  sqliteFree(x.z);
}

/*
** Usage:  sqlite_test_create_function DB

*/
typedef struct CountCtx CountCtx;
struct CountCtx {
  int n;
};
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  CountCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  if( (argc==0 || SQLITE3_NULL!=sqlite3_value_type(argv[0]) ) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite3_context *context){
  CountCtx *p;
  p = sqlite3_get_context(context, sizeof(*p));
  sqlite3_result_int32(context, p ? p->n : 0);
}

/*
** Usage:  sqlite_test_create_aggregate DB
**
** Call the sqlite3_create_function API on the given database in order

/*
** The following routine is a user-defined SQL function whose purpose
** is to test the sqlite_set_result() API.
*/
static void testFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  while( argc>=2 ){
    const char *zArg0 = sqlite3_value_data(argv[0]);
    const char *zArg1 = sqlite3_value_data(argv[1]);
    if( zArg0==0 ){
      sqlite3_result_error(context, "first argument to test function "
         "may not be NULL", -1);
    }else if( sqlite3StrICmp(zArg0,"string")==0 ){
      sqlite3_result_text(context, zArg1, -1, 1);
    }else if( zArg1==0 ){
      sqlite3_result_error(context, "2nd argument may not be NULL if the "

  if( rc!=SQLITE_DONE && rc!=SQLITE_ROW ) return TCL_ERROR;
  Tcl_SetResult(interp, (char *)errorName(rc), 0);
  return TCL_OK;
}

/*
** Usage: sqlite3_column_data STMT column
**
** Advance the statement to the next row.
*/
static int test_column_data(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_stmt *pStmt;
  int col;
  Tcl_Obj *pRet;

  if( objc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", 
       Tcl_GetString(objv[0]), " STMT column", 0);
    return TCL_ERROR;
  }

  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;

  if( SQLITE3_BLOB==sqlite3_column_type(pStmt, col) ){
    int len = sqlite3_column_bytes(pStmt, col);
    pRet = Tcl_NewByteArrayObj(sqlite3_column_data(pStmt, col), len);
  }else{
    pRet = Tcl_NewStringObj(sqlite3_column_data(pStmt, col), -1);
  }
  Tcl_SetObjResult(interp, pRet);

  return TCL_OK;
}

/*
** Usage: sqlite3_column_data16 STMT column
**
** Advance the statement to the next row.
*/
static int test_column_data16(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3_stmt *pStmt;
  int col;
  Tcl_Obj *pRet;
  int len;

  if( objc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", 
       Tcl_GetString(objv[0]), " STMT column", 0);
    return TCL_ERROR;
  }

  if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR;
  if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR;

  len = sqlite3_column_bytes16(pStmt, col);
  pRet = Tcl_NewByteArrayObj(sqlite3_column_data16(pStmt, col), len);
  Tcl_SetObjResult(interp, pRet);

  return TCL_OK;
}

/*
** Usage: sqlite3_column_name STMT column

     { "sqlite3_prepare",               (Tcl_ObjCmdProc*)test_prepare       },
     { "sqlite3_prepare16",             (Tcl_ObjCmdProc*)test_prepare16     },
     { "sqlite3_open",                  (Tcl_ObjCmdProc*)test_open          },
     { "sqlite3_open16",                (Tcl_ObjCmdProc*)test_open16        },
     { "sqlite3_finalize",              (Tcl_ObjCmdProc*)test_finalize      },
     { "sqlite3_reset",                 (Tcl_ObjCmdProc*)test_reset         },
     { "sqlite3_step",                  (Tcl_ObjCmdProc*)test_step},
     { "sqlite3_column_data",           (Tcl_ObjCmdProc*)test_column_data   },
     { "sqlite3_column_data16",         (Tcl_ObjCmdProc*)test_column_data16 },
     { "sqlite3_column_count",          (Tcl_ObjCmdProc*)test_column_count  },
     { "sqlite3_column_name",           (Tcl_ObjCmdProc*)test_column_name   },
     { "sqlite3_column_name16",         (Tcl_ObjCmdProc*)test_column_name16 },
     { "sqlite3_column_type",           (Tcl_ObjCmdProc*)test_column_type   },
     { "sqlite3_column_int",            (Tcl_ObjCmdProc*)test_column_int   },
     { "sqlite3_data_count",            (Tcl_ObjCmdProc*)test_data_count   },
     { "add_reverse_collating_func",    (Tcl_ObjCmdProc*)reverse_collfunc   },

/*
** 2003 December 18
**
** 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.
**
*************************************************************************
** Code for testing the the SQLite library in a multithreaded environment.
**
** $Id: test4.c,v 1.7 2004/05/26 02:04:57 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#if defined(OS_UNIX) && OS_UNIX==1 && defined(THREADSAFE) && THREADSAFE==1
#include <stdlib.h>
#include <string.h>

    p->rc = SQLITE_ERROR;
    return;
  }
  p->rc = sqlite3_step(p->pStmt);
  if( p->rc==SQLITE_ROW ){
    p->argc = sqlite3_column_count(p->pStmt);
    for(i=0; i<sqlite3_data_count(p->pStmt); i++){
      p->argv[i] = sqlite3_column_data(p->pStmt, i);
    }
    for(i=0; i<p->argc; i++){
      p->colv[i] = sqlite3_column_name(p->pStmt, i);
    }
  }
}

    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
  }
  return TCL_OK;
}
#else
int Sqlitetest4_Init(Tcl_Interp *interp){ return TCL_OK; }
#endif /* OS_UNIX */

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.335 2004/05/26 16:54:47 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

/*
** This macro takes a single parameter, a pointer to a Mem structure.
** It returns the string encoding for the Mem structure, one of TEXT_Utf8
** TEXT_Utf16le or TEXT_Utf16be.
*/
#define MemEnc(p) ( \
   p->flags&MEM_Utf16le?TEXT_Utf16le: \
  (p->flags&MEM_Utf16le?TEXT_Utf16be:TEXT_Utf8) )

/*
** The following macros each take one parameter, a pointer to a Mem
** structure. The value returned is non-zero if the value stored in 
** the Mem structure is of or can be losslessly converted to the
** type implicit in the macro name.
** 
** MemIsNull     # NULL values
** MemIsInt      # Ints and reals and strings that can be converted to ints.
** MemIsReal     # Reals, ints and strings that look like numbers
** MemIsStr      # Strings, reals and ints.
** MemIsBlob     # Blobs.
**
** These macros do not alter the contents of the Mem structure.
*/
#define MemIsNull(p) ((p)->flags&Mem_Null)
#define MemIsBlob(p) ((p)->flags&Mem_Blob)
#define MemIsStr(p) ((p)->flags&(MEM_Int|MEM_Real|MEM_Str))
#define MemIsInt(p) ((p)->flags&(MEM_Int|MEM_Real) || hardMemIsInt(p))
#define MemIsReal(p) ((p)->flags&(MEM_Int|MEM_Real) || hardMemIsReal(p))
static int hardMemIsInt(Mem *p){
  assert( !(p->flags&(MEM_Int|MEM_Real)) );
  if( p->flags&MEM_Str ){
    int realnum = 0;
    if( sqlite3IsNumber(p->z, &realnum, MemEnc(p)) && !realnum ){
      return 1;
    }
  }
  return 0;
}
static int hardMemIsReal(Mem *p){
  assert( !(p->flags&(MEM_Int|MEM_Real)) );
  if( p->flags&MEM_Str && sqlite3IsNumber(p->z, 0, MemEnc(p)) ){
    return 1;
  }
  return 0;
}

/*
** The following two macros each take one parameter, a pointer to a Mem
** structure. They return the value stored in the Mem structure coerced
** to a 64-bit integer or real, respectively.
**
** MemInt
** MemReal
**
** These macros do not alter the contents of the Mem structure, although
** they may cache the integer or real value cast of the value.
*/
#define MemInt(p) (((p)->flags&MEM_Int)?(p)->i:hardMemInt(p))
#define MemReal(p) (((p)->flags&MEM_Real)?(p)->r:hardMemReal(p))
static i64 hardMemInt(Mem *p){
  assert( !(p->flags&MEM_Int) );
  if( !MemIsInt(p) ) return 0;

  if( p->flags&MEM_Real ){
    p->i = p->r;
  }else{
    assert( p->flags&MEM_Str );
    sqlite3atoi64(p->z, &(p->i), MemEnc(p));
  }
  p->flags |= MEM_Int;
  return p->i;
}
static double hardMemReal(Mem *p){
  assert( !(p->flags&MEM_Real) );
  if( !MemIsReal(p) ) return 0.0;

  if( p->flags&MEM_Int ){
    p->r = p->i;
  }else{
    assert( p->flags&MEM_Str );
    /* p->r = sqlite3AtoF(p->z, 0, MemEnc(p)); */
    p->r = sqlite3AtoF(p->z, 0);
  }
  p->flags |= MEM_Real;
  return p->r;
}


#if 0
/*
** MemStr(Mem *pMem)
** MemBlob(Mem *pMem)
** MemBloblen(Mem *pMem)
**
** MemType(Mem *pMem)
**
** MemSetBlob
** MemSetStr
**
** MemSetEnc
** MemSetType
**
** MemCopy
*/
struct MemRecord {
  char *zData;    /* Serialized record */
  int nField;     /* Number of fields in the header */
  int nHeader;    /* Number of bytes in the entire header */
  u64 *aType;     /* Type values for all entries in the record */
};
typedef struct MemRecord MemRecord;

/*
** Transform the value stored in pMem, which must be a blob into a
** MemRecord. An Mem cell used to store a MemRecord works as follows:
**
** Mem.z points at a MemRecord struct
*/
static int Recordify(Mem *pMem){
  return 0;
}
#endif

/*
** Release the memory associated with the given stack level.  This
** leaves the Mem.flags field in an inconsistent state.
*/
#define Release(P) if((P)->flags&MEM_Dyn){ sqliteFree((P)->z); }

/*
** Parameter "enc" is one of TEXT_Utf8, TEXT_Utf16le or TEXT_Utf16be.
** Return the corresponding MEM_Utf* value.
*/
static int encToFlags(u8 enc){
  switch( enc ){
    case TEXT_Utf8: return MEM_Utf8;
    case TEXT_Utf16be: return MEM_Utf16be;
    case TEXT_Utf16le: return MEM_Utf16le;
  }
  assert(0);
}

/*
** Set the encoding flags of memory cell "pMem" to the correct values
** for the database encoding "enc" (one of TEXT_Utf8, TEXT_Utf16le or
** TEXT_Utf16be).
*/
#define SetEncodingFlags(pMem, enc) ((pMem)->flags = \
((pMem->flags & ~(MEM_Utf8|MEM_Utf16le|MEM_Utf16be))) | encToFlags(enc))
static int SetEncoding(Mem*, int);

/*
** Set the MEM_TypeStr, MEM_TypeReal or MEM_TypeInt flags in pMem if
** required.
*/
static void MemSetTypeFlags(Mem *pMem){
  int f = pMem->flags;
  if( f&MEM_Int ) pMem->flags |= MEM_TypeInt;
  else if( f&MEM_Real ) pMem->flags |= MEM_TypeReal;
  else if( f&MEM_Str ) pMem->flags |= MEM_TypeStr;
}


/*
** Convert the given stack entity into a string if it isn't one
** already. Return non-zero if a malloc() fails.
*/
#define Stringify(P, enc) \
if( !((P)->flags&(MEM_Str|MEM_Blob)) ) hardStringify(P, enc);
static int hardStringify(Mem *pStack, u8 enc){
  int rc = SQLITE_OK;
  int fg = pStack->flags;

  assert( !(fg&(MEM_Str|MEM_Blob)) );
  assert( fg&(MEM_Int|MEM_Real|MEM_Null) );

  memcpy(z, pStack->z, pStack->n);
  pStack->z = z;
  pStack->flags &= ~MEM_Ephem;
  pStack->flags |= MEM_Dyn;
  return 0;
}

/*
** If pMem is a string object, this routine sets the encoding of the string
** (to one of UTF-8 or UTF16) and whether or not the string is
** nul-terminated. If pMem is not a string object, then this routine is
** a no-op.
**
** The second argument, "flags" consists of one of MEM_Utf8, MEM_Utf16le
** or MEM_Utf16be, possible ORed with MEM_Term. If necessary this function 
** manipulates the value stored by pMem so that it matches the flags passed
** in "flags".
**
** SQLITE_OK is returned if the conversion is successful (or not required).
** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
int SetEncoding(Mem *pMem, int flags){
  u8 enc1;    /* Current string encoding (TEXT_Utf* value) */
  u8 enc2;    /* Required string encoding (TEXT_Utf* value) */

  /* If this is not a string, do nothing. */
  if( !(pMem->flags&MEM_Str) ){
    return SQLITE_OK;
  }

  enc1 = flagsToEnc(pMem->flags);
  enc2 = flagsToEnc(flags);

  if( enc1!=enc2 ){
    if( enc1==TEXT_Utf8 || enc2==TEXT_Utf8 ){
      /* If the current encoding does not match the desired encoding, then
      ** we will need to do some translation between encodings.
      */
      char *z;
      int n;
      int rc = sqlite3utfTranslate(pMem->z,pMem->n,enc1,(void **)&z,&n,enc2);
      if( rc!=SQLITE_OK ){
        return rc;
      }
  
      /* Result of sqlite3utfTranslate is currently always dynamically
      ** allocated and nul terminated. This might be altered as a performance
      ** enhancement later.
      */
      pMem->z = z;
      pMem->n = n;
      pMem->flags &= ~(MEM_Utf8|MEM_Utf16le|MEM_Utf16be);
      pMem->flags &= ~(MEM_Static|MEM_Short|MEM_Ephem);
      pMem->flags |= (MEM_Dyn|MEM_Term|flags);
    }else{
      /* Must be translating between UTF-16le and UTF-16be. */
      int i;
      if( pMem->flags&MEM_Static ){
        Dynamicify(pMem, enc1);
      }
      for(i=0; i<pMem->n; i+=2){
        char c = pMem->z[i];
        pMem->z[i] = pMem->z[i+1];
        pMem->z[i+1] = c;
      }
      SetEncodingFlags(pMem, enc2);
    }
  }

  if( (flags&MEM_Term) && !(pMem->flags&MEM_Term) ){
    /* If we did not do any translation, but currently the string is
    ** not nul terminated (and is required to be), then we add the
    ** nul terminator now. We never have to do this if we translated
    ** the encoding of the string, as the translation functions return
    ** nul terminated values.
    */
    int f = pMem->flags;
    int nulTermLen = 2;     /* The number of 0x00 bytes to append */
    if( enc2==MEM_Utf8 ){
      nulTermLen = 1;
    }

    if( pMem->n+nulTermLen<=NBFS ){
      /* If the string plus the nul terminator will fit in the Mem.zShort
      ** buffer, and it is not already stored there, copy it there.
      */
      if( !(f&MEM_Short) ){
        memcpy(pMem->z, pMem->zShort, pMem->n);
        if( f&MEM_Dyn ){
          sqliteFree(pMem->z);
        }
        pMem->z = pMem->zShort;
        pMem->flags &= ~(MEM_Static|MEM_Ephem|MEM_Dyn);
        pMem->flags |= MEM_Short;
      }
    }else{
      /* Otherwise we have to malloc for memory. If the string is already
      ** dynamic, use sqliteRealloc(). Otherwise sqliteMalloc() enough
      ** space for the string and the nul terminator, and copy the string
      ** data there.
      */
      if( f&MEM_Dyn ){
        pMem->z = (char *)sqliteRealloc(pMem->z, pMem->n+nulTermLen);
        if( !pMem->z ){
          return SQLITE_NOMEM;
        }
      }else{
        char *z = (char *)sqliteMalloc(pMem->n+nulTermLen);
        memcpy(z, pMem->z, pMem->n);
        pMem->z = z;
        pMem->flags &= ~(MEM_Static|MEM_Ephem|MEM_Short);
        pMem->flags |= MEM_Dyn;
      }
    }

    /* pMem->z now points at the string data, with enough space at the end
    ** to insert the nul nul terminator. pMem->n has not yet been updated.
    */
    memcpy(&pMem->z[pMem->n], "\0\0", nulTermLen);
    pMem->n += nulTermLen;
    pMem->flags |= MEM_Term;
  }
  return SQLITE_OK;
}

/*
** Convert the given stack entity into a integer if it isn't one
** already.
**
** Any prior string or real representation is invalidated.  
** NULLs are converted into 0.
*/

  }else{
    pStack->r = 0.0;
  }
/*  pStack->flags |= MEM_Real; */
  pStack->flags = MEM_Real;
}

/*
** Execute the statement pStmt, either until a row of data is ready, the
** statement is completely executed or an error occurs.
*/
int sqlite3_step(sqlite3_stmt *pStmt){
  Vdbe *p = (Vdbe*)pStmt;
  sqlite *db;
  int rc;

  if( p->magic!=VDBE_MAGIC_RUN ){
    return SQLITE_MISUSE;
  }
  db = p->db;
  if( sqlite3SafetyOn(db) ){
    p->rc = SQLITE_MISUSE;
    return SQLITE_MISUSE;
  }
  if( p->explain ){
    rc = sqlite3VdbeList(p);
  }else{
    rc = sqlite3VdbeExec(p);
  }

  if( sqlite3SafetyOff(db) ){
    rc = SQLITE_MISUSE;
  }

  sqlite3Error(p->db, rc, p->zErrMsg);
  return rc;
}

/*
** Return the number of columns in the result set for the statement pStmt.
*/
int sqlite3_column_count(sqlite3_stmt *pStmt){
  Vdbe *pVm = (Vdbe *)pStmt;
  return pVm->nResColumn;
}

/*
** Return the number of values available from the current row of the
** currently executing statement pStmt.
*/
int sqlite3_data_count(sqlite3_stmt *pStmt){
  Vdbe *pVm = (Vdbe *)pStmt;
  if( !pVm->resOnStack ) return 0;
  return pVm->nResColumn;
}

/*
** Return the value of the 'i'th column of the current row of the currently
** executing statement pStmt.
*/
const unsigned char *sqlite3_column_data(sqlite3_stmt *pStmt, int i){
  int vals;
  Vdbe *pVm = (Vdbe *)pStmt;
  Mem *pVal;

  vals = sqlite3_data_count(pStmt);
  if( i>=vals || i<0 ){
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return 0;
  }

  pVal = &pVm->pTos[(1-vals)+i];
  return sqlite3_value_data((sqlite3_value *)pVal);
}

/*
** pVal is a Mem* cast to an sqlite_value* value. Return a pointer to
** the nul terminated UTF-8 string representation if the value is 
** not a blob or NULL. If the value is a blob, then just return a pointer
** to the blob of data. If it is a NULL, return a NULL pointer.
**
** This function may translate the encoding of the string stored by
** pVal. The MEM_Utf8, MEM_Utf16le and MEM_Utf16be flags must be set
** correctly when this function is called. If a translation occurs,
** the flags are set to reflect the new encoding of the string.
**
** If a translation fails because of a malloc() failure, a NULL pointer
** is returned.
*/
const unsigned char *sqlite3_value_data(sqlite3_value *pVal){
  int flags = pVal->flags;

  if( flags&MEM_Null ){
    /* For a NULL return a NULL Pointer */
    return 0;
  }

  if( flags&MEM_Str ){
    /* If there is already a string representation, make sure it is in
    ** encoded in UTF-8.
    */
    SetEncoding(pVal, MEM_Utf8|MEM_Term);
  }else if( !(flags&MEM_Blob) ){
    if( flags&MEM_Int ){
      sqlite3_snprintf(NBFS, pVal->zShort, "%lld", pVal->i);
    }else{
      assert( flags&MEM_Real );
      sqlite3_snprintf(NBFS, pVal->zShort, "%.15g", pVal->r);
    }
    pVal->z = pVal->zShort;
    pVal->n = strlen(pVal->z)+1;
    pVal->flags |= (MEM_Str|MEM_Short);
  }

  return pVal->z;
}

/*
** pVal is a Mem* cast to an sqlite_value* value. Return a pointer to
** the nul terminated UTF-16 string representation if the value is 
** not a blob or NULL. If the value is a blob, then just return a pointer
** to the blob of data. If it is a NULL, return a NULL pointer.
**
** The byte-order of the returned string data is the machines native byte
** order.
**
** This function may translate the encoding of the string stored by
** pVal. The MEM_Utf8, MEM_Utf16le and MEM_Utf16be flags must be set
** correctly when this function is called. If a translation occurs,
** the flags are set to reflect the new encoding of the string.
**
** If a translation fails because of a malloc() failure, a NULL pointer
** is returned.
*/
const void *sqlite3_value_data16(sqlite3_value* pVal){
  if( pVal->flags&MEM_Null ){
    /* For a NULL return a NULL Pointer */
    return 0;
  }

  if( pVal->flags&MEM_Str ){
    /* If there is already a string representation, make sure it is in
    ** encoded in UTF-16 machine byte order.
    */
    SetEncoding(pVal, encToFlags(TEXT_Utf16)|MEM_Term);
  }else if( !(pVal->flags&MEM_Blob) ){
    sqlite3_value_data(pVal);
    SetEncoding(pVal, encToFlags(TEXT_Utf16)|MEM_Term);
  }

  return (const void *)(pVal->z);
}

/*
** Return the value of the 'i'th column of the current row of the currently
** executing statement pStmt.
*/
const void *sqlite3_column_data16(sqlite3_stmt *pStmt, int i){
  int vals;
  Vdbe *pVm = (Vdbe *)pStmt;
  Mem *pVal;

  vals = sqlite3_data_count(pStmt);
  if( i>=vals || i<0 ){
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return 0;
  }

  pVal = &pVm->pTos[(1-vals)+i];
  return sqlite3_value_data16((sqlite3_value *)pVal);
}

/*
** Return the number of bytes of data that will be returned by the
** equivalent sqlite3_value_data() call.
*/
int sqlite3_value_bytes(sqlite3_value *pVal){
  if( sqlite3_value_data(pVal) ){
    return ((Mem *)pVal)->n;
  }
  return 0;
}

/*
** Return the number of bytes of data that will be returned by the
** equivalent sqlite3_value_data16() call.
*/
int sqlite3_value_bytes16(sqlite3_value *pVal){
  if( sqlite3_value_data16(pVal) ){
    return ((Mem *)pVal)->n;
  }
  return 0;
}

/*
** Return the value of the sqlite_value* argument coerced to a 64-bit
** integer.
*/
long long int sqlite3_value_int(sqlite3_value *pVal){
  Mem *pMem = (Mem *)pVal;
  return MemInt(pMem);
}

/*
** Return the value of the sqlite_value* argument coerced to a 64-bit
** IEEE float.
*/
double sqlite3_value_float(sqlite3_value *pVal){
  Mem *pMem = (Mem *)pVal;
  return MemReal(pMem);
}

/*
** Return the number of bytes of data that will be returned by the
** equivalent sqlite3_column_data() call.
*/
int sqlite3_column_bytes(sqlite3_stmt *pStmt, int i){
  Vdbe *pVm = (Vdbe *)pStmt;

  if( sqlite3_column_data(pStmt, i) ){
    int vals = sqlite3_data_count(pStmt);
    return pVm->pTos[(1-vals)+i].n;
  }
  return 0;
}

/*
** Return the number of bytes of data that will be returned by the
** equivalent sqlite3_column_data16() call.
*/
int sqlite3_column_bytes16(sqlite3_stmt *pStmt, int i){
  Vdbe *pVm = (Vdbe *)pStmt;

  if( sqlite3_column_data16(pStmt, i) ){
    int vals = sqlite3_data_count(pStmt);
    return pVm->pTos[(1-vals)+i].n;
  }
  return 0;
}

/*
** Return the value of the 'i'th column of the current row of the currently
** executing statement pStmt.
*/
long long int sqlite3_column_int(sqlite3_stmt *pStmt, int i){
  int vals;
  Vdbe *pVm = (Vdbe *)pStmt;
  Mem *pVal;

  vals = sqlite3_data_count(pStmt);
  if( i>=vals || i<0 ){
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return 0;
  }

  pVal = &pVm->pTos[(1-vals)+i];
  return sqlite3_value_int(pVal);
}

/*
** Return the value of the 'i'th column of the current row of the currently
** executing statement pStmt.
*/
double sqlite3_column_float(sqlite3_stmt *pStmt, int i){
  int vals;
  Vdbe *pVm = (Vdbe *)pStmt;
  Mem *pVal;

  vals = sqlite3_data_count(pStmt);
  if( i>=vals || i<0 ){
    sqlite3Error(pVm->db, SQLITE_RANGE, 0);
    return 0;
  }

  pVal = &pVm->pTos[(1-vals)+i];
  return sqlite3_value_float(pVal);
}

/*
** Return the name of the Nth column of the result set returned by SQL
** statement pStmt.
*/
const char *sqlite3_column_name(sqlite3_stmt *pStmt, int N){
  Vdbe *p = (Vdbe *)pStmt;
  Mem *pColName;

  if( N>=sqlite3_column_count(pStmt) || N<0 ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return 0;
  }

  pColName = &(p->aColName[N]);
  return sqlite3_value_data(pColName);
}

/*
** Return the name of the 'i'th column of the result set of SQL statement
** pStmt, encoded as UTF-16.
*/
const void *sqlite3_column_name16(sqlite3_stmt *pStmt, int N){
  Vdbe *p = (Vdbe *)pStmt;
  Mem *pColName;

  if( N>=sqlite3_column_count(pStmt) || N<0 ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return 0;
  }

  pColName = &(p->aColName[N]);
  return sqlite3_value_data16(pColName);
}


/*
** Return the type of the value stored in the sqlite_value* object.
*/
int sqlite3_value_type(sqlite3_value* pVal){
  int f = ((Mem *)pVal)->flags;
  if( f&MEM_Null ){
    return SQLITE3_NULL;
  }
  if( f&MEM_TypeInt ){
    return SQLITE3_INTEGER;
  }
  if( f&MEM_TypeReal ){
    return SQLITE3_FLOAT;
  }
  if( f&MEM_TypeStr ){
    return SQLITE3_TEXT;
  }
  if( f&MEM_Blob ){
    return SQLITE3_BLOB;
  }
  assert(0);
}

/*
** Return the type of the 'i'th column of the current row of the currently
** executing statement pStmt.
*/
int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
  int vals;
  Vdbe *p = (Vdbe *)pStmt;

  vals = sqlite3_data_count(pStmt);
  if( i>=vals || i<0 ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return 0;
  }

  return sqlite3_value_type(&(p->pTos[(1-vals)+i]));
}

/*
** This routine returns either the column name, or declaration type (see
** sqlite3_column_decltype16() ) of the 'i'th column of the result set of
** SQL statement pStmt. The returned string is UTF-16 encoded.
**
** The declaration type is returned if 'decltype' is true, otherwise
** the column name.
*/
static const void *columnName16(sqlite3_stmt *pStmt, int i, int decltype){
  Vdbe *p = (Vdbe *)pStmt;

  if( i>=sqlite3_column_count(pStmt) || i<0 ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return 0;
  }

  if( decltype ){
    i += p->nResColumn;
  }

  if( !p->azColName16 ){
    p->azColName16 = (void **)sqliteMalloc(sizeof(void *)*p->nResColumn*2);
    if( !p->azColName16 ){
      sqlite3Error(p->db, SQLITE_NOMEM, 0);
      return 0;
    }
  }
  if( !p->azColName16[i] ){
    if( SQLITE3_BIGENDIAN ){
      p->azColName16[i] = sqlite3utf8to16be(p->azColName[i], -1);
    }
    if( !p->azColName16[i] ){
      sqlite3Error(p->db, SQLITE_NOMEM, 0);
      return 0;
    }
  }
  return p->azColName16[i];
}

/*
** Return the column declaration type (if applicable) of the 'i'th column
** of the result set of SQL statement pStmt, encoded as UTF-8.
*/
const char *sqlite3_column_decltype(sqlite3_stmt *pStmt, int i){
  Vdbe *p = (Vdbe *)pStmt;

  if( i>=sqlite3_column_count(pStmt) || i<0 ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return 0;
  }

  return p->azColName[i+p->nResColumn];
}

/*
** Return the column declaration type (if applicable) of the 'i'th column
** of the result set of SQL statement pStmt, encoded as UTF-16.
*/
const void *sqlite3_column_decltype16(sqlite3_stmt *pStmt, int i){
  return columnName16(pStmt, i, 1);
}

/*
** Unbind the value bound to variable $i in virtual machine p. This is the 
** the same as binding a NULL value to the column. If the "i" parameter is
** out of range, then SQLITE_RANGE is returned. Othewise SQLITE_OK.
**
** The error code stored in database p->db is overwritten with the return
** value in any case.
*/
static int vdbeUnbind(Vdbe *p, int i){
  Mem *pVar;
  if( p->magic!=VDBE_MAGIC_RUN || p->pc!=0 ){
    sqlite3Error(p->db, SQLITE_MISUSE, 0);
    return SQLITE_MISUSE;
  }
  if( i<1 || i>p->nVar ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return SQLITE_RANGE;
  }
  i--;
  pVar = &p->apVar[i];
  if( pVar->flags&MEM_Dyn ){
    sqliteFree(pVar->z);
  }
  pVar->flags = MEM_Null;
  sqlite3Error(p->db, SQLITE_OK, 0);
  return SQLITE_OK;
}

/*
** This routine is used to bind text or blob data to an SQL variable (a ?).
** It may also be used to bind a NULL value, by setting zVal to 0. Any
** existing value is unbound.
**
** The error code stored in p->db is overwritten with the return value in
** all cases.
*/
static int vdbeBindBlob(
  Vdbe *p,           /* Virtual machine */
  int i,             /* Var number to bind (numbered from 1 upward) */
  const char *zVal,  /* Pointer to blob of data */
  int bytes,         /* Number of bytes to copy */
  int copy,          /* True to copy the memory, false to copy a pointer */
  int flags          /* Valid combination of MEM_Blob, MEM_Str, MEM_Term */
){
  Mem *pVar;
  int rc;

  rc = vdbeUnbind(p, i);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pVar = &p->apVar[i-1];

  if( zVal ){
    pVar->n = bytes;
    pVar->flags = flags;
    if( !copy ){
      pVar->z = (char *)zVal;
      pVar->flags |= MEM_Static;
    }else{
      if( bytes>NBFS ){
        pVar->z = (char *)sqliteMalloc(bytes);
        if( !pVar->z ){
          sqlite3Error(p->db, SQLITE_NOMEM, 0);
          return SQLITE_NOMEM;
        }
        pVar->flags |= MEM_Dyn;
      }else{
        pVar->z = pVar->zShort;
        pVar->flags |= MEM_Short;
      }
      memcpy(pVar->z, zVal, bytes);
    }
  }

  return SQLITE_OK;
}

/*
** Bind a 64 bit integer to an SQL statement variable.
*/
int sqlite3_bind_int64(sqlite3_stmt *p, int i, long long int iValue){
  int rc;
  Vdbe *v = (Vdbe *)p;
  rc = vdbeUnbind(v, i);
  if( rc==SQLITE_OK ){
    Mem *pVar = &v->apVar[i-1];
    pVar->flags = MEM_Int;
    pVar->i = iValue;
  }
  return rc;
}

/*
** Bind a 32 bit integer to an SQL statement variable.
*/
int sqlite3_bind_int32(sqlite3_stmt *p, int i, int iValue){
  return sqlite3_bind_int64(p, i, (long long int)iValue);
}

/*
** Bind a double (real) to an SQL statement variable.
*/
int sqlite3_bind_double(sqlite3_stmt *p, int i, double iValue){
  int rc;
  Vdbe *v = (Vdbe *)p;
  rc = vdbeUnbind(v, i);
  if( rc==SQLITE_OK ){
    Mem *pVar = &v->apVar[i-1];
    pVar->flags = MEM_Real;
    pVar->r = iValue;
  }
  return SQLITE_OK;
}

/*
** Bind a NULL value to an SQL statement variable.
*/
int sqlite3_bind_null(sqlite3_stmt* p, int i){
  return vdbeUnbind((Vdbe *)p, i);
}

/*
** Bind a UTF-8 text value to an SQL statement variable.
*/
int sqlite3_bind_text( 
  sqlite3_stmt *pStmt, 
  int i, 
  const char *zData, 
  int nData, 
  int eCopy
){
  Mem *pVar;
  Vdbe *p = (Vdbe *)pStmt;
  int rc = SQLITE_OK;
  u8 db_enc = p->db->enc;            /* Text encoding of the database */

  /* Unbind any previous variable value */
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    pVar = &p->apVar[i-1];

    if( !zData ){
      /* If zData is NULL, then bind an SQL NULL value */
      pVar->flags = MEM_Null;
    }else{
      if( zData && nData<0 ){
        nData = strlen(zData) + 1;
      }
      pVar->z = (char *)zData;
      pVar->n = nData;
      pVar->flags = MEM_Utf8|MEM_Str|(zData[nData-1]?0:MEM_Term);
      if( !eCopy || db_enc!=TEXT_Utf8 ){
        pVar->flags |= MEM_Static;
        rc = SetEncoding(pVar, encToFlags(db_enc)|MEM_Term);
      }else{
        pVar->flags |= MEM_Ephem;
        Deephemeralize(pVar);
      }
    }
  }

  sqlite3Error(p->db, rc, 0);
  return rc;

no_mem:
  sqlite3Error(p->db, SQLITE_NOMEM, 0);
  return SQLITE_NOMEM;
}

/*
** Bind a UTF-16 text value to an SQL statement variable.
*/
int sqlite3_bind_text16(
  sqlite3_stmt *pStmt, 
  int i, 
  const void *zData, 
  int nData, 
  int eCopy
){
  Vdbe *p = (Vdbe *)pStmt;
  Mem *pVar;
  u8 db_enc = p->db->enc;            /* Text encoding of the database */
  u8 txt_enc;
  int null_term = 0;
  int rc;

  rc = vdbeUnbind(p, i);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  pVar = &p->apVar[i-1];

  /* If zData is NULL, then bind an SQL NULL value */
  if( !zData ){
    pVar->flags = MEM_Null;
    return SQLITE_OK;
  }

  if( db_enc==TEXT_Utf8 ){
    /* If the database encoding is UTF-8, then do a translation. */
    pVar->z = sqlite3utf16to8(zData, nData, SQLITE3_BIGENDIAN);
    if( !pVar->z ) return SQLITE_NOMEM;
    pVar->n = strlen(pVar->z)+1;
    pVar->flags = MEM_Str|MEM_Term|MEM_Dyn;
    return SQLITE_OK;
  }
 
  /* There may or may not be a byte order mark at the start of the UTF-16.
  ** Either way set 'txt_enc' to the TEXT_Utf16* value indicating the 
  ** actual byte order used by this string. If the string does happen
  ** to contain a BOM, then move zData so that it points to the first
  ** byte after the BOM.
  */
  txt_enc = sqlite3UtfReadBom(zData, nData);
  if( txt_enc ){
    zData = (void *)(((u8 *)zData) + 2);
  }else{
    txt_enc = SQLITE3_BIGENDIAN?TEXT_Utf16be:TEXT_Utf16le;
  }

  if( nData<0 ){
    nData = sqlite3utf16ByteLen(zData, -1) + 2;
    null_term = 1;
  }else if( nData>1 && !((u8*)zData)[nData-1] && !((u8*)zData)[nData-2] ){
    null_term = 1;
  }

  if( db_enc==txt_enc && !eCopy ){
    /* If the byte order of the string matches the byte order of the
    ** database and the eCopy parameter is not set, then the string can
    ** be used without making a copy.
    */
    pVar->z = (char *)zData;
    pVar->n = nData;
    pVar->flags = MEM_Str|MEM_Static|(null_term?MEM_Term:0);
  }else{
    /* Make a copy. Swap the byte order if required */
    pVar->n = nData + (null_term?0:2);
    pVar->z = sqliteMalloc(pVar->n);
    pVar->flags = MEM_Str|MEM_Dyn|MEM_Term;
    if( db_enc==txt_enc ){
      memcpy(pVar->z, zData, nData);
    }else{
      swab(zData, pVar->z, nData);
    }
    pVar->z[pVar->n-1] = '\0';
    pVar->z[pVar->n-2] = '\0';
  }

  return SQLITE_OK;
}

/*
** Bind a blob value to an SQL statement variable.
*/
int sqlite3_bind_blob(
  sqlite3_stmt *p, 
  int i, 
  const void *zData, 
  int nData, 
  int eCopy
){
  return vdbeBindBlob((Vdbe *)p, i, zData, nData, eCopy, MEM_Blob);
}


/*
** Insert a new aggregate element and make it the element that
** has focus.
**
** Return 0 on success and 1 if memory is exhausted.

case OP_String: {
  char *z = pOp->p3;
  u8 op = pOp->opcode;

  pTos++;
  pTos->flags = 0;
 
  if( z ){
    /* FIX ME: For now the code in expr.c always puts UTF-8 in P3. It
    ** should transform text to the native encoding before doing so.
    */
    MemSetStr(pTos, z, -1, TEXT_Utf8, 0);
    SetEncoding(pTos, encToFlags(db->enc)|MEM_Term);
  }else if( op==OP_String ){
    pTos->flags = MEM_Null;
  }

  /* If this is an OP_Real or OP_Integer opcode, set the pTos->r or pTos->i
  ** values respectively.
  */
  if( op==OP_Real ){
    assert( z );
    assert( sqlite3IsNumber(z, 0, TEXT_Utf8) );
    pTos->r = sqlite3AtoF(z, 0);
    pTos->flags |= MEM_Real;
  }else if( op==OP_Integer ){

    pTos->i = pOp->p1;
    if( pTos->i==0 && pOp->p3 ){
      sqlite3GetInt64(z, &pTos->i);
    }













    pTos->flags |= MEM_Int;







  }

  break;
}

/* Opcode: Variable P1 * *
**

case OP_Callback: {
  int i;
  assert( p->nResColumn==pOp->p1 );

  for(i=0; i<pOp->p1; i++){
    Mem *pVal = &pTos[0-i];
    SetEncodingFlags(pVal, db->enc);
    MemNulTerminate(pVal);
    MemSetTypeFlags(pVal);
  }

  p->resOnStack = 1;
  p->nCallback++;
  p->popStack = pOp->p1;
  p->pc = pc + 1;
  p->pTos = pTos;

  n = pOp->p1;
  apVal = p->apArg;
  assert( apVal || n==0 );

  pArg = &pTos[1-n];
  for(i=0; i<n; i++, pArg++){
    SetEncodingFlags(pArg, db->enc);
    MemSetTypeFlags(pArg);
    apVal[i] = pArg;
  }

  ctx.pFunc = (FuncDef*)pOp->p3;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.isError = 0;

  pRec = &pTos[-n];
  assert( pRec>=p->aStack );

  apVal = p->apArg;
  assert( apVal || n==0 );

  for(i=0; i<n; i++, pRec++){
    apVal[i] = pRec;
    SetEncodingFlags(pRec, db->enc);
    MemSetTypeFlags(pRec);
  }
  i = pTos->i;
  assert( i>=0 && i<p->agg.nMem );
  ctx.pFunc = (FuncDef*)pOp->p3;
  pMem = &p->agg.pCurrent->aMem[i];
  ctx.s.z = pMem->zShort;  /* Space used for small aggregate contexts */
  ctx.pAgg = pMem->z;

  int flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  double r;           /* Real value */
  char *z;            /* String or BLOB value */
  char zShort[NBFS];  /* Space for short strings */
};
typedef struct Mem Mem;

/*
** The following three macros are used to set the value and manifest type
** stored by a Mem structure.
**
** MemSetNull - Set the value to NULL.
** MemSetInt  - Set the value to an integer.
** MemSetReal - Set the value to a real.
** MemSetStr - Set the value to a string (or blob if enc==0).
*/
#define MemSetNull(p) sqlite3VdbeMemSetNull(p)
#define MemSetInt(p,v) sqlite3VdbeMemSetInt(p,v)
#define MemSetReal(p,v) sqlite3VdbeMemSetReal(p,v)
#define MemSetStr(p,z,n,enc,eCopy) sqlite3VdbeMemSetStr(p,z,n,enc,eCopy)

/*
** This macro is used to ensure a string stored in a Mem struct is NULL
** terminated. When used on an object that is not a string or is a nul
** terminated string this is a no-op. When used on a non-nul-terminated
** string a nul terminator character is appended.
**
** Non-zero is returned if a malloc() fails.
*/
#define MemNulTerminate(p) \
if( ((p)->flags&MEM_Str) && !((p)->flags&MEM_Term) ) sqlite3VdbeMemNulTerminate(p);

/* One or more of the following flags are set to indicate the valid
** representations of the value stored in the Mem struct.
**
** If the MEM_Null flag is set, then the value is an SQL NULL value.
** No other flags may be set in this case.
**
** If the MEM_Str flag is set then Mem.z points at a string representation.

** flags, which describe the text encoding of the string if the MEM_Str
** flag is true, are not generally valid for Mem* objects handled by the
** VDBE.
**
** When a user-defined function is called (see OP_Function), the Mem*
** objects that store the argument values for the function call are 
** passed to the user-defined function routine cast to sqlite3_value*.
** The user routine may then call sqlite3_value_data() or
** sqlite3_value_data16() to request a UTF-8 or UTF-16 string. If the
** string representation currently stored in Mem.z is not the requested
** encoding, then a translation occurs. To keep track of things, the
** MEM_Utf* flags are set correctly for the database encoding before a
** user-routine is called, and kept up to date if any translations occur
** thereafter.
** 
** When sqlite3_step() returns SQLITE3_ROW, indicating that a row of data
** is ready for processing by the caller, the data values are stored
** internally as Mem* objects. Before sqlite3_step() returns, the MEM_Utf*
** flags are set correctly for the database encoding. A translation may
** take place if the user requests a non-native encoding via
** sqlite3_column_data() or sqlite3_column_data16(). If this occurs, then
** the MEM_Utf* flags are updated accordingly.
*/
#define MEM_Utf8      0x2000   /* String uses UTF-8 encoding */
#define MEM_Utf16be   0x4000   /* String uses UTF-16 big-endian */
#define MEM_Utf16le   0x8000   /* String uses UTF-16 little-endian */

/* The following MEM_ value appears only in AggElem.aMem.s.flag fields.

** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite3_context structure which is only defined in
** this source file.
*/
void *sqlite3_get_context(sqlite3_context *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  if( p->pAgg==0 ){
    if( nByte<=NBFS ){
      p->pAgg = (void*)p->s.z;
      memset(p->pAgg, 0, nByte);
    }else{
      p->pAgg = sqliteMalloc( nByte );

     0
  };

  assert( p->explain );

  /* Even though this opcode does not put dynamic strings onto the
  ** the stack, they may become dynamic if the user calls
  ** sqlite3_column_data16(), causing a translation to UTF-16 encoding.
  */
  if( p->pTos==&p->aStack[4] ){
    for(i=0; i<5; i++){
      if( p->aStack[i].flags & MEM_Dyn ){
        sqliteFree(p->aStack[i].z);
      }
      p->aStack[i].flags = 0;