SQLite

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.205 2004/05/31 18:51:58 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

    {"INT",  3, SQLITE_AFF_INTEGER},
    {"CHAR", 4, SQLITE_AFF_TEXT},
    {"CLOB", 4, SQLITE_AFF_TEXT},
    {"TEXT", 4, SQLITE_AFF_TEXT},
    {"BLOB", 4, SQLITE_AFF_NONE},
  };

  if( nType==0 ){
    return SQLITE_AFF_NONE;
  }
  for(i=0; i<sizeof(substrings)/sizeof(substrings[0]); i++){
    int c1 = substrings[i].zSub[0];
    int c2 = tolower(c1);
    int limit = nType - substrings[i].nSub;
    const char *z = substrings[i].zSub;
    for(n=0; n<=limit; n++){
      int c = zType[n];

** 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 1.27 2004/05/31 18:51:58 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.

** argv[1] and following are modifiers.  Parse them all and write
** 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( SQLITE_NULL==sqlite3_value_type(argv[0]) || 
      parseDateOrTime(sqlite3_value_text(argv[0]), p) ) return 1;
  for(i=1; i<argc; i++){
    if( SQLITE_NULL==sqlite3_value_type(argv[i]) || 
        parseModifier(sqlite3_value_text(argv[i]), p) ) return 1;
  }
  return 0;
}


/*

** 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 1.62 2004/05/31 18:51:58 drh Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"
#include "vdbeInt.h"

  int mask;    /* 0 for min() or 0xffffffff for max() */
  int iBest;

  if( argc==0 ) return;
  mask = (int)sqlite3_user_data(context);
  assert( mask==-1 || mask==0 );
  iBest = 0;
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  for(i=1; i<argc; i++){
    if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
    if( (sqlite3MemCompare(argv[iBest], argv[i], 0)^mask)>=0 ){
      iBest = i;
    }
  }
  sqlite3_result_value(context, argv[iBest]);
}

/*
** Return the type of the argument.
*/
static void typeofFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  const char *z = 0;
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_NULL:    z = "null";    break;
    case SQLITE_INTEGER: z = "integer"; break;
    case SQLITE_TEXT:    z = "text";    break;
    case SQLITE_FLOAT:   z = "real";    break;
    case SQLITE_BLOB:    z = "blob";    break;
  }
  sqlite3_result_text(context, z, -1, 0);
}

/*
** Implementation of the length() function
*/
static void lengthFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int len;

  assert( argc==1 );
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_BLOB:
    case SQLITE_INTEGER:
    case SQLITE_FLOAT: {
      sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
      break;
    }
    case SQLITE_TEXT: {
      const char *z = sqlite3_value_text(argv[0]);
      for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
      sqlite3_result_int(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){
  assert( argc==1 );
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_INTEGER: {
      i64 iVal = sqlite3_value_int64(argv[0]);
      if( iVal<0 ) iVal = iVal * -1;
      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 * -1.0;
      sqlite3_result_double(context, rVal);

*/
static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
  int n = 0;
  double r;
  char zBuf[100];
  assert( argc==1 || argc==2 );
  if( argc==2 ){
    if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
    n = sqlite3_value_int(argv[1]);
    if( n>30 ) n = 30;
    if( n<0 ) n = 0;
  }
  if( SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
  r = sqlite3_value_double(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 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
  z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
  if( z==0 ) return;
  strcpy(z, sqlite3_value_text(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 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
  z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
  if( z==0 ) return;
  strcpy(z, sqlite3_value_text(argv[0]));
  for(i=0; z[i]; i++){
    if( isupper(z[i]) ) z[i] = tolower(z[i]);
  }
  sqlite3_result_text(context, z, -1, 1);

static void ifnullFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int i;
  for(i=0; i<argc; i++){
    if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
      sqlite3_result_value(context, argv[i]);
      break;
    }
  }
}

/*

** 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){
  if( argc<1 ) return;
  switch( sqlite3_value_type(argv[0]) ){
    case SQLITE_NULL: {
      sqlite3_result_text(context, "NULL", 4, 0);
      break;
    }
    case SQLITE_INTEGER:
    case SQLITE_FLOAT: {
      sqlite3_result_value(context, argv[0]);
      break;
    }
    case SQLITE_BLOB:  /*** FIX ME.  Use a BLOB encoding ***/
    case SQLITE_TEXT: {
      int i,j,n;
      const char *zArg = sqlite3_value_text(argv[0]);
      char *z;

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

/*
** 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_aggregate_context(context, sizeof(*p));
  if( p && SQLITE_NULL!=sqlite3_value_type(argv[0]) ){
    p->sum += sqlite3_value_double(argv[0]);
    p->cnt++;
  }
}
static void sumFinalize(sqlite3_context *context){
  SumCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));

/*
** Routines to implement the count() aggregate function.
*/
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite3_context *context){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  sqlite3_result_int(context, p ? p->n : 0);

*/
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_aggregate_context(context, sizeof(*pBest));

  if( SQLITE_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
    ** sqlite3_user_data() function returns (void *)-1. For min() it
    ** returns (void *)db, where db is the sqlite3* database pointer.

**
*************************************************************************
** 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: main.c,v 1.199 2004/05/31 18:51:58 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** A pointer to this structure is used to communicate information
** from sqlite3Init into the sqlite3InitCallback.
*/
typedef struct {
  sqlite *db;         /* The database being initialized */
  char **pzErrMsg;    /* Error message stored here */
} InitData;

/*
** The following constant value is used by the SQLITE_BIGENDIAN and
** SQLITE_LITTLEENDIAN macros.
*/
const int sqlite3one = 1;

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
*/

  void *pUserData,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
){
  int rc;
  char *zFunctionName8;
  zFunctionName8 = sqlite3utf16to8(zFunctionName, -1, SQLITE_BIGENDIAN);
  if( !zFunctionName8 ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_create_function(db, zFunctionName8, nArg, eTextRep, 
      iCollateArg, pUserData, xFunc, xStep, xFinal);
  sqliteFree(zFunctionName8);
  return rc;

    static char outOfMemBe[] = {
      0, 'o', 0, 'u', 0, 't', 0, ' ', 
      0, 'o', 0, 'f', 0, ' ', 
      0, 'm', 0, 'e', 0, 'm', 0, 'o', 0, 'r', 0, 'y', 0, 0, 0
    };
    static char *outOfMemLe = &outOfMemBe[1];

    if( SQLITE_BIGENDIAN ){
      return (void *)outOfMemBe;
    }else{
      return (void *)outOfMemLe;
    }
  }
  if( !db->zErrMsg16 ){
    char const *zErr8 = sqlite3_errmsg(db);
    if( SQLITE_BIGENDIAN ){
      db->zErrMsg16 = sqlite3utf8to16be(zErr8, -1);
    }else{
      db->zErrMsg16 = sqlite3utf8to16le(zErr8, -1);
    }
  }
  return db->zErrMsg16;
}

  ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
  ** tricky bit is figuring out the pointer to return in *pzTail.
  */
  char *zSql8 = 0;
  char const *zTail8 = 0;
  int rc;

  zSql8 = sqlite3utf16to8(zSql, nBytes, SQLITE_BIGENDIAN);
  if( !zSql8 ){
    sqlite3Error(db, SQLITE_NOMEM, 0);
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);

  if( zTail8 && pzTail ){

  const char **options
){
  char *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
  int rc;

  assert( ppDb );

  zFilename8 = sqlite3utf16to8(zFilename, -1, SQLITE_BIGENDIAN);
  if( !zFilename8 ){
    *ppDb = 0;
    return SQLITE_NOMEM;
  }

  /* FIX ME: Also need to translate the option strings */

  if( SQLITE_BIGENDIAN ){
    rc = openDatabase(zFilename8, ppDb, options, TEXT_Utf16be);
  }else{
    rc = openDatabase(zFilename8, ppDb, options, TEXT_Utf16le);
  }

  sqliteFree(zFilename8);
  return rc;

**    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 1.86 2004/05/31 18:51:58 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++.

*/
int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** Values are stored in the database in one of the following fundamental
** types.
*/
#define SQLITE_INTEGER  1
#define SQLITE_FLOAT    2
#define SQLITE_TEXT     3
#define SQLITE_BLOB     4
#define SQLITE_NULL     5

/*
** The next group of routines returns information about the information
** in a single column of the current result row of a query.  In every
** case the first parameter is a pointer to the SQL statement that is being
** executed (the sqlite_stmt* that was returned from sqlite3_prepare()) and
** the second argument is the index of the column for which information 

/*
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.265 2004/05/31 18:51:58 drh Exp $
*/
#include "config.h"
#include "sqlite3.h"
#include "hash.h"
#include "parse.h"
#include <stdio.h>
#include <stdlib.h>

typedef unsigned INTPTR_TYPE uptr; /* Big enough to hold a pointer */

/*
** Macros to determine whether the machine is big or little endian,
** evaluated at runtime.
*/
extern const int sqlite3one;
#define SQLITE_BIGENDIAN    (*(char *)(&sqlite3one)==0)
#define SQLITE_LITTLEENDIAN (*(char *)(&sqlite3one)==1)

/*
** Defer sourcing vdbe.h until after the "u8" typedef is defined.
*/
#include "vdbe.h"
#include "btree.h"

/*
** Possible values for the Db.textEnc field.
*/
#define TEXT_Utf8          1
#define TEXT_Utf16le       2
#define TEXT_Utf16be       3
#define TEXT_Utf16         (SQLITE_BIGENDIAN?TEXT_Utf16be:TEXT_Utf16le)

/*
** Each database is an instance of the following structure.
**
** The sqlite.temp_store determines where temporary database files
** are stored.  If 1, then a file is created to hold those tables.  If
** 2, then they are held in memory.  0 means use the default value in

/*
** 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 1.77 2004/05/31 18:51:58 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_DString cmd;
  int i;
  int rc;

  Tcl_DStringInit(&cmd);
  Tcl_DStringAppend(&cmd, p->zScript, -1);
  for(i=0; i<argc; i++){
    if( SQLITE_NULL==sqlite3_value_type(argv[i]) ){
      Tcl_DStringAppendElement(&cmd, "");
    }else{
      Tcl_DStringAppendElement(&cmd, sqlite3_value_text(argv[i]));
    }
  }
  rc = Tcl_Eval(p->interp, Tcl_DStringValue(&cmd));
  if( rc ){

      }

      while( pStmt && SQLITE_ROW==sqlite3_step(pStmt) ){
        for(i=0; i<sqlite3_column_count(pStmt); i++){
          Tcl_Obj *pVal;
          
          /* Set pVal to contain the i'th column of this row. */
          if( SQLITE_BLOB!=sqlite3_column_type(pStmt, i) ){
            pVal = dbTextToObj(sqlite3_column_text(pStmt, i));
          }else{
            int bytes = sqlite3_column_bytes(pStmt, i);
            pVal = Tcl_NewByteArrayObj(sqlite3_column_blob(pStmt, i), bytes);
          }
  
          if( objc==5 ){

**    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 1.66 2004/05/31 18:51:58 drh 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( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
      sqlite3_result_text(context, sqlite3_value_text(argv[i]), -1, 1);
      break;
    }
  }
}

/*

typedef struct CountCtx CountCtx;
struct CountCtx {
  int n;
};
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0]) ) && p ){
    p->n++;
  }
}   
static void countFinalize(sqlite3_context *context){
  CountCtx *p;
  p = sqlite3_aggregate_context(context, sizeof(*p));
  sqlite3_result_int(context, p ? p->n : 0);

  }

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

  tp = sqlite3_column_type(pStmt, col);
  switch( tp ){
    case SQLITE_INTEGER: 
      Tcl_SetResult(interp, "INTEGER", TCL_STATIC); 
      break;
    case SQLITE_NULL:
      Tcl_SetResult(interp, "NULL", TCL_STATIC); 
      break;
    case SQLITE_FLOAT:
      Tcl_SetResult(interp, "FLOAT", TCL_STATIC); 
      break;
    case SQLITE_TEXT:
      Tcl_SetResult(interp, "TEXT", TCL_STATIC); 
      break;
    case SQLITE_BLOB:
      Tcl_SetResult(interp, "BLOB", TCL_STATIC); 
      break;
    default:
      assert(0);
  }

  return TCL_OK;

*************************************************************************
** Code for testing the utf.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library. Specifically, the code in this file
** is used for testing the SQLite routines for converting between
** the various supported unicode encodings.
**
** $Id: test5.c,v 1.6 2004/05/31 18:51:58 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"         /* to get SQLITE_BIGENDIAN */
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

/*
** Return the number of bytes up to and including the first pair of
** 0x00 bytes in *pStr.

  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " <utf-16 encoded-string>", 0);
    return TCL_ERROR;
  }

  in = Tcl_GetByteArrayFromObj(objv[1], 0);
  out = sqlite3utf16to8(in, -1, SQLITE_BIGENDIAN);
  res = Tcl_NewByteArrayObj(out, strlen(out)+1);
  sqliteFree(out);

  Tcl_SetObjResult(interp, res);

  return TCL_OK;
}

  int i;
  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
    Tcl_CreateObjCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
  }

  return TCL_OK;
}

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.75 2004/05/31 18:51:58 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*

/*
** This routine is the same as the sqlite3_complete() routine described
** above, except that the parameter is required to be UTF-16 encoded, not
** UTF-8.
*/
int sqlite3_complete16(const void *zSql){
  int rc;
  char *zSql8 = sqlite3utf16to8(zSql, -1, SQLITE_BIGENDIAN);
  if( !zSql8 ) return 0;
  rc = sqlite3_complete(zSql8);
  sqliteFree(zSql8);
  return rc;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used to translate between UTF-8, 
** UTF-16, UTF-16BE, and UTF-16LE.
**
** $Id: utf.c,v 1.15 2004/05/31 18:51:58 drh Exp $
**
** Notes on UTF-8:
**
**   Byte-0    Byte-1    Byte-2    Byte-3    Value
**  0xxxxxxx                                 00000000 00000000 0xxxxxxx
**  110yyyyy  10xxxxxx                       00000000 00000yyy yyxxxxxx
**  1110zzzz  10yyyyyy  10xxxxxx             00000000 zzzzyyyy yyxxxxxx

  int n;                /* Allocated length of pZ in bytes */
  int c;                /* Number of pZ bytes already read or written */
};

/* TODO: Implement this macro in os.h. It should be 1 on big-endian
** machines, and 0 on little-endian.
*/
#define SQLITE_NATIVE_BIGENDIAN 0

#if SQLITE_NATIVE_BIGENDIAN == 1
#define BOM_BIGENDIAN 0x0000FFFE
#define BOM_LITTLEENDIAN 0x0000FEFF
#else
#define BOM_BIGENDIAN 0x0000FEFF
#define BOM_LITTLEENDIAN 0x0000FFFE
#endif

  inout.c = 0;
  inout.n = N;

  if( inout.n<0 ){
    inout.n = sqlite3utf16ByteLen(inout.pZ, -1);
  }

  if( readUtf16Bom(&inout, SQLITE_BIGENDIAN)!=big_endian ){
    /* swab(&inout.pZ[inout.c], inout.pZ, inout.n-inout.c); */
    int i;
    for(i=0; i<(inout.n-inout.c); i += 2){
      char c1 = inout.pZ[i+inout.c];
      char c2 = inout.pZ[i+inout.c+1];
      inout.pZ[i] = c2;
      inout.pZ[i+1] = c1;

**
** 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 1.353 2004/05/31 18:51:58 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

** stack variables.  This routine sets the pMem->enc and pMem->type
** variables used by the sqlite3_value_*() routines.
*/
#define storeTypeInfo(A,B) _storeTypeInfo(A)
static void _storeTypeInfo(Mem *pMem){
  int flags = pMem->flags;
  if( flags & MEM_Null ){
    pMem->type = SQLITE_NULL;
  }
  else if( flags & MEM_Int ){
    pMem->type = SQLITE_INTEGER;
  }
  else if( flags & MEM_Real ){
    pMem->type = SQLITE_FLOAT;
  }
  else if( flags & MEM_Str ){
    pMem->type = SQLITE_TEXT;
  }else{
    pMem->type = SQLITE_BLOB;
  }
}

/*
** Insert a new aggregate element and make it the element that
** has focus.
**

** Internally, the vdbe manipulates nearly all SQL values as Mem
** structures. Each Mem struct may cache multiple representations (string,
** integer etc.) of the same value.  A value (and therefore Mem structure)
** has the following properties:
**
** Each value has a manifest type. The manifest type of the value stored
** in a Mem struct is returned by the MemType(Mem*) macro. The type is
** one of SQLITE_NULL, SQLITE_INTEGER, SQLITE_REAL, SQLITE_TEXT or
** SQLITE_BLOB.
*/
struct Mem {
  i64 i;              /* Integer value */
  int n;              /* Number of characters in string value, including '\0' */
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  type;           /* One of MEM_Null, MEM_Str, etc. */
  u8  enc;            /* TEXT_Utf8, TEXT_Utf16le, or TEXT_Utf16be */

  ** byte after the BOM.
  */
  txt_enc = sqlite3UtfReadBom(zData, nData);
  if( txt_enc ){
    zData = (void *)(((u8 *)zData) + 2);
    nData -= 2;
  }else{
    txt_enc = SQLITE_BIGENDIAN?TEXT_Utf16be:TEXT_Utf16le;
  }
  rc = sqlite3VdbeMemSetStr(pVar, zData, nData, txt_enc, eCopy);
  if( rc ){
    return rc;
  }
  rc = sqlite3VdbeChangeEncoding(pVar, p->db->enc);
  return rc;

    }
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, sqlite3_error_string(p->rc), (char*)0);
  }else{
    Op *pOp = &p->aOp[i];
    Mem *pMem = p->aStack;
    pMem->flags = MEM_Int;
    pMem->type = SQLITE_INTEGER;
    pMem->i = i;                                /* Program counter */
    pMem++;

    pMem->flags = MEM_Static|MEM_Str|MEM_Term;
    pMem->z = sqlite3OpcodeNames[pOp->opcode];  /* Opcode */
    pMem->n = strlen(pMem->z);
    pMem->type = SQLITE_TEXT;
    pMem->enc = TEXT_Utf8;
    pMem++;

    pMem->flags = MEM_Int;
    pMem->i = pOp->p1;                          /* P1 */
    pMem->type = SQLITE_INTEGER;
    pMem++;

    pMem->flags = MEM_Int;
    pMem->i = pOp->p2;                          /* P2 */
    pMem->type = SQLITE_INTEGER;
    pMem++;

    pMem->flags = MEM_Short|MEM_Str|MEM_Term;   /* P3 */
    pMem->z = displayP3(pOp, pMem->zShort, sizeof(pMem->zShort));
    pMem->type = SQLITE_TEXT;
    pMem->enc = TEXT_Utf8;

    p->nResColumn = 5;
    p->pTos = pMem;
    p->rc = SQLITE_OK;
    p->resOnStack = 1;
    rc = SQLITE_ROW;

    /* For a Real or Integer, use sqlite3_snprintf() to produce the UTF-8
    ** string representation of the value. Then, if the required encoding
    ** is UTF-16le or UTF-16be do a translation.
    ** 
    ** FIX ME: It would be better if sqlite3_snprintf() could do UTF-16.
    */
    u8 *z = pMem->zShort;
    if( fg & MEM_Real || (pMem->type==SQLITE_FLOAT) ){
      sqlite3_snprintf(NBFS, z, "%.15g", pMem->r);
    }else{
      assert( fg & MEM_Int );
      sqlite3_snprintf(NBFS, z, "%lld", pMem->i);
    }
    pMem->n = strlen(z);
    pMem->z = z;

** Add MEM_Real to the set of representations for pMem.  Prior
** prior representations other than MEM_Null retained.  NULL is
** converted into 0.0.
*/
int sqlite3VdbeMemRealify(Mem *pMem){
  if( pMem->flags & MEM_Real ){
    /* Do nothing */
  }else if( (pMem->flags & MEM_Int) && pMem->type!=SQLITE_TEXT ){
    pMem->r = pMem->i;
  }else if( pMem->flags & (MEM_Str|MEM_Blob) ){
    if( sqlite3VdbeChangeEncoding(pMem, TEXT_Utf8)
       || sqlite3VdbeMemNulTerminate(pMem) ){
      return SQLITE_NOMEM;
    }
    assert( pMem->z );

/*
** Delete any previous value and set the value stored in *pMem to NULL.
*/
void sqlite3VdbeMemSetNull(Mem *pMem){
  releaseMem(pMem);
  pMem->flags = MEM_Null;
  pMem->type = SQLITE_NULL;
}

/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type INTEGER.
*/
void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){
  releaseMem(pMem);
  pMem->i = val;
  pMem->flags = MEM_Int;
  pMem->type = SQLITE_INTEGER;
}

/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type REAL.
*/
void sqlite3VdbeMemSetDouble(Mem *pMem, double val){
  releaseMem(pMem);
  pMem->r = val;
  pMem->flags = MEM_Real;
  pMem->type = SQLITE_FLOAT;
}

/*
** Copy the contents of memory cell pFrom into pTo.
*/
int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
  releaseMem(pTo);

  int n,              /* Bytes in string, or negative */
  u8 enc,             /* Encoding of z.  0 for BLOBs */
  int eCopy           /* True if this function should make a copy of z */
){
  releaseMem(pMem);
  if( !z ){
    pMem->flags = MEM_Null;
    pMem->type = SQLITE_NULL;
    return SQLITE_OK;
  }

  pMem->z = (char *)z;
  if( eCopy ){
    pMem->flags = MEM_Ephem;
  }else{
    pMem->flags = MEM_Static;
  }
  pMem->enc = enc;
  pMem->type = enc==0 ? SQLITE_BLOB : SQLITE_TEXT;
  pMem->n = n;
  switch( enc ){
    case 0:
      pMem->flags |= MEM_Blob;
      break;

    case TEXT_Utf8:

      pMem->flags = MEM_Blob|MEM_Dyn|MEM_Term;
    }else{
      zData = &(pMem->zShort[0]);
      pMem->flags = MEM_Blob|MEM_Short|MEM_Term;
    }
    pMem->z = zData;
    pMem->enc = 0;
    pMem->type = SQLITE_BLOB;

    if( key ){
      rc = sqlite3BtreeKey(pCur, offset, amt, zData);
    }else{
      rc = sqlite3BtreeData(pCur, offset, amt, zData);
    }
    zData[amt] = 0;

set rcsid {$Id: capi3.tcl,v 1.2 2004/05/31 18:51:59 drh Exp $}
source common.tcl
header {C/C++ Interface For SQLite Version 3}
puts {
<h2>C/C++ Interface For SQLite Version 3</h2>

<h3>1.0 Overview</h3>

text error message for the most recent error.  The error message will
be represented in UTF-8 and will be ephemeral - it could disappear on
the next call to any SQLite API function.  sqlite3_errmsg16() works like
sqlite3_errmsg() except that it returns the error message represented
as UTF-16 in host native byte order.
</p>

<p>
The error codes for SQLite version 3 are unchanged from version2.
They are as follows:
</p>

<blockquote><pre>
#define SQLITE_OK           0   /* Successful result */
#define SQLITE_ERROR        1   /* SQL error or missing database */
#define SQLITE_INTERNAL     2   /* An internal logic error in SQLite */
#define SQLITE_PERM         3   /* Access permission denied */
#define SQLITE_ABORT        4   /* Callback routine requested an abort */
#define SQLITE_BUSY         5   /* The database file is locked */
#define SQLITE_LOCKED       6   /* A table in the database is locked */
#define SQLITE_NOMEM        7   /* A malloc() failed */
#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite_interrupt() */
#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
#define SQLITE_NOTFOUND    12   /* (Internal Only) Table or record not found */
#define SQLITE_FULL        13   /* Insertion failed because database is full */
#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
#define SQLITE_PROTOCOL    15   /* Database lock protocol error */
#define SQLITE_EMPTY       16   /* (Internal Only) Database table is empty */
#define SQLITE_SCHEMA      17   /* The database schema changed */
#define SQLITE_TOOBIG      18   /* Too much data for one row of a table */
#define SQLITE_CONSTRAINT  19   /* Abort due to contraint violation */
#define SQLITE_MISMATCH    20   /* Data type mismatch */
#define SQLITE_MISUSE      21   /* Library used incorrectly */
#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
#define SQLITE_AUTH        23   /* Authorization denied */
#define SQLITE_ROW         100  /* sqlite_step() has another row ready */
#define SQLITE_DONE        101  /* sqlite_step() has finished executing */
</pre></blockquote>

<h4>2.2 Executing SQL statements</h4>

<blockquote><pre>
   typedef struct sqlite3_stmt sqlite3_stmt;
   int sqlite3_prepare(sqlite3*, const char*, sqlite3_stmt**, const char**);
   int sqlite3_prepare16(sqlite3*, const void*, sqlite3_stmt**, const void**);
   int sqlite3_finalize(sqlite3_stmt*);

The sqlite3_column_count() function returns the number of columns in
the results set.   The sqlite3_column_type() function returns the
datatype for the value in the Nth column.  The return value is one
of these:
</p>

<blockquote><pre>
   #define SQLITE_INTEGER  1
   #define SQLITE_FLOAT    2
   #define SQLITE_TEXT     3
   #define SQLITE_BLOB     4
   #define SQLITE_NULL     5
</pre></blockquote>

<p>
The sqlite3_column_decltype() routine returns text which is the
declared type of the column in the CREATE TABLE statement.  For an
expression, the return type is an empty string.  sqlite3_column_name()
returns the name of the Nth column.  sqlite3_column_bytes() returns

set rcsid {$Id: datatype3.tcl,v 1.2 2004/05/31 18:51:59 drh Exp $}
source common.tcl
header {Datatypes In SQLite Version 3}
puts {
<h2>Datatypes In SQLite Version 3</h2>

<h3>1. Storage Classes</h3>

	is assigned INTEGER affinity.</P>

	<LI><P>If the datatype of the column contains any of the strings
	&quot;CHAR&quot;, &quot;CLOB&quot;, or &quot;TEXT&quot; then that
	column has TEXT affinity. Notice that the type VARCHAR contains the
	string &quot;CHAR&quot; and is thus assigned TEXT affinity.</P>

	<LI><P>If the datatype for a column
         contains the string &quot;BLOB&quot; or if
        not datatype is specified then the column has affinity NONE.</P>

	<LI><P>Otherwise, the affinity is NUMERIC.  Notice that a column
        where no datatype is specified is given affinity NUMERIC.</P>
</OL>

<P>If a table is created using a "CREATE TABLE &lt;table&gt; AS
SELECT..." statement, then all columns have no datatype specified
and they are given no affinity.</P>

<h4>2.2 Column Affinity Example</h4>

<blockquote>
<PRE>CREATE TABLE t1(
    t  TEXT,
    nu NUMERIC, 
    i  INTEGER,
    no BLOB
);

-- Storage classes for the following row:
-- TEXT, REAL, INTEGER, TEXT
INSERT INTO t1 VALUES('500.0', '500.0', '500.0', '500.0');

-- Storage classes for the following row:
-- TEXT, REAL, INTEGER, REAL
INSERT INTO t1 VALUES(500.0, 500.0, 500.0, 500.0);
</PRE>
</blockquote>

<h3>3. Comparison Expressions</h3>

<P>Like SQLite version 2, version 3
features the binary comparison operators '=',
'&lt;', '&lt;=', '&gt;=' and '!=', an operation to test for set

	affinity is applied to both values before the comparison takes
	place.</P>
</UL>

<h4>3.1 Comparison Example</h4>

<blockquote>
<PRE>
CREATE TABLE t1(
    a TEXT,
    b NUMERIC,
    c BLOB
);

-- Storage classes for the following row:
-- TEXT, REAL, TEXT
INSERT INTO t1 VALUES('500', '500', '500');

-- 60 and 40 are converted to '60' and '40' and values are compared as TEXT.
SELECT a &lt; 60, a &lt; 40 FROM t1;
1|0

-- Comparisons are numeric. No conversions are required.
SELECT b &lt; 60, b &lt; 600 FROM t1;
0|1

-- Both 60 and 600 (storage class NUMERIC) are less than '500'
-- (storage class TEXT).
SELECT c &lt; 60, c &lt; 600 FROM t1;
0|0
</PRE>
</blockquote>

<P>
In SQLite, the expression "a BETWEEN b AND c" is currently
equivalent to "a &gt;= b AND a &lt;= c". SQLite will continue to
treat the two as exactly equivalent, even if this means that
different affinities are applied to 'a' in each of the comparisons