**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.35 2007/12/13 21:54:11 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
................................................................................
  assert( iDb>=0 );

#ifndef SQLITE_OMIT_TRIGGER
  /* Drop any table triggers from the internal schema. */
  for(pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext){
    int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
    assert( iTrigDb==iDb || iTrigDb==1 );
    sqlite3VdbeOp3(v, OP_DropTrigger, iTrigDb, 0, pTrig->name, 0);
  }
#endif

  /* Drop the table and index from the internal schema */
  sqlite3VdbeOp3(v, OP_DropTable, iDb, 0, pTab->zName, 0);

  /* Reload the table, index and permanent trigger schemas. */
  zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName);
  if( !zWhere ) return;
  sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, zWhere, P3_DYNAMIC);

#ifndef SQLITE_OMIT_TRIGGER
  /* Now, if the table is not stored in the temp database, reload any temp 
  ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. 
  */
  if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
    sqlite3VdbeOp3(v, OP_ParseSchema, 1, 0, zWhere, P3_DYNAMIC);
  }
#endif
}

/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
** command. 
................................................................................
  /* If this is a virtual table, invoke the xRename() function if
  ** one is defined. The xRename() callback will modify the names
  ** of any resources used by the v-table implementation (including other
  ** SQLite tables) that are identified by the name of the virtual table.
  */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( isVirtualRename ){
    sqlite3VdbeOp3(v, OP_String8, 0, 0, zName, 0);
    sqlite3VdbeOp3(v, OP_VRename, 0, 0, (const char*)pTab->pVtab, P3_VTAB);
  }
#endif

  /* figure out how many UTF-8 characters are in zName */
  zTabName = pTab->zName;
  nTabName = sqlite3Utf8CharLen(zTabName, -1);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that used to generate VDBE code
** that implements the ALTER TABLE command.
**
** $Id: alter.c,v 1.36 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
................................................................................
  assert( iDb>=0 );

#ifndef SQLITE_OMIT_TRIGGER
  /* Drop any table triggers from the internal schema. */
  for(pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext){
    int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
    assert( iTrigDb==iDb || iTrigDb==1 );
    sqlite3VdbeAddOp4(v, OP_DropTrigger, iTrigDb, 0, 0, pTrig->name, 0);
  }
#endif

  /* Drop the table and index from the internal schema */
  sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);

  /* Reload the table, index and permanent trigger schemas. */
  zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName);
  if( !zWhere ) return;
  sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);

#ifndef SQLITE_OMIT_TRIGGER
  /* Now, if the table is not stored in the temp database, reload any temp 
  ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. 
  */
  if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
    sqlite3VdbeAddOp4(v, OP_ParseSchema, 1, 0, 0, zWhere, P4_DYNAMIC);
  }
#endif
}

/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" 
** command. 
................................................................................
  /* If this is a virtual table, invoke the xRename() function if
  ** one is defined. The xRename() callback will modify the names
  ** of any resources used by the v-table implementation (including other
  ** SQLite tables) that are identified by the name of the virtual table.
  */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( isVirtualRename ){
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, zName, 0);
    sqlite3VdbeAddOp4(v, OP_VRename, 0, 0, 0,(const char*)pTab->pVtab, P4_VTAB);
  }
#endif

  /* figure out how many UTF-8 characters are in zName */
  zTabName = pTab->zName;
  nTabName = sqlite3Utf8CharLen(zTabName, -1);

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.26 2008/01/02 14:28:13 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
       "DELETE FROM %Q.sqlite_stat1 WHERE tbl=%Q",
       pDb->zName, zWhere
    );
    iRootPage = pStat->tnum;
  }else{
    /* The sqlite_stat1 table already exists.  Delete all rows. */
    iRootPage = pStat->tnum;
    sqlite3VdbeAddOp(v, OP_Clear, pStat->tnum, iDb);
  }

  /* Open the sqlite_stat1 table for writing. Unless it was created
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( iRootPage>0 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, iStatCur, iRootPage);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iStatCur, 3);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
................................................................................
  iIdxCur = pParse->nTab;
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);

    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
    VdbeComment((v, "%s", pIdx->zName));
    sqlite3VdbeOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum,
        (char *)pKey, P3_KEYINFO_HANDOFF);
    nCol = pIdx->nColumn;
    if( iMem+nCol*2>=pParse->nMem ){
      pParse->nMem = iMem+nCol*2+1;
    }
    sqlite3VdbeAddOp(v, OP_SetNumColumns, iIdxCur, nCol+1);

    /* Memory cells are used as follows:
    **
    **    mem[iMem]:             The total number of rows in the table.
    **    mem[iMem+1]:           Number of distinct values in column 1
    **    ...
    **    mem[iMem+nCol]:        Number of distinct values in column N
................................................................................
    **    ...
    **    mem[iMem+nCol+nCol]:   Last observed value of column N
    **
    ** Cells iMem through iMem+nCol are initialized to 0.  The others
    ** are initialized to NULL.
    */
    for(i=0; i<=nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem+i);
    }
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemNull, 0, iMem+nCol+i+1);
    }

    /* Do the analysis.
    */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp(v, OP_MemIncr, 1, iMem);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp(v, OP_Column, iIdxCur, i);
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+nCol+i+1, 0);
      sqlite3VdbeAddOp(v, OP_Ne, 0x100, 0);
    }
    sqlite3VdbeAddOp(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){
      addr = sqlite3VdbeAddOp(v, OP_MemIncr, 1, iMem+i+1);
      sqlite3VdbeChangeP2(v, topOfLoop + 3*i + 3, addr);
      sqlite3VdbeAddOp(v, OP_Column, iIdxCur, i);
      sqlite3VdbeAddOp(v, OP_MemStore, iMem+nCol+i+1, 1);
    }
    sqlite3VdbeResolveLabel(v, endOfLoop);
    sqlite3VdbeAddOp(v, OP_Next, iIdxCur, topOfLoop);
    sqlite3VdbeAddOp(v, OP_Close, iIdxCur, 0);

    /* Store the results.  
    **
    ** The result is a single row of the sqlite_stat1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entires
................................................................................
    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
    addr = sqlite3VdbeAddOp(v, OP_IfNot, 0, 0);
    sqlite3VdbeAddOp(v, OP_NewRowid, iStatCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pIdx->zName, 0);
    sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, " ", 0);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0);
      sqlite3VdbeAddOp(v, OP_Add, 0, 0);
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0);
      sqlite3VdbeAddOp(v, OP_Divide, 0, 0);
      sqlite3VdbeAddOp(v, OP_ToInt, 0, 0);
      if( i==nCol-1 ){
        sqlite3VdbeAddOp(v, OP_Concat, nCol*2-1, 0);
      }else{
        sqlite3VdbeAddOp(v, OP_Dup, 1, 0);
      }
    }
    sqlite3VdbeOp3(v, OP_MakeRecord, 3, 0, "aaa", 0);
    sqlite3VdbeAddOp(v, OP_Insert, iStatCur, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Generate code that will cause the most recent index analysis to
** be laoded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_LoadAnalysis, iDb, 0);
  }
}

/*
** Generate code that will do an analysis of an entire database
*/
static void analyzeDatabase(Parse *pParse, int iDb){

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.27 2008/01/03 00:01:24 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.
................................................................................
       "DELETE FROM %Q.sqlite_stat1 WHERE tbl=%Q",
       pDb->zName, zWhere
    );
    iRootPage = pStat->tnum;
  }else{
    /* The sqlite_stat1 table already exists.  Delete all rows. */
    iRootPage = pStat->tnum;
    sqlite3VdbeAddOp2(v, OP_Clear, pStat->tnum, iDb);
  }

  /* Open the sqlite_stat1 table for writing. Unless it was created
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( iRootPage>0 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }
  sqlite3VdbeAddOp1(v, OP_Integer, iDb);
  sqlite3VdbeAddOp2(v, OP_OpenWrite, iStatCur, iRootPage);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, iStatCur, 3);
}

/*
** Generate code to do an analysis of all indices associated with
** a single table.
*/
static void analyzeOneTable(
................................................................................
  iIdxCur = pParse->nTab;
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);

    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
    sqlite3VdbeAddOp1(v, OP_Integer, iDb);
    VdbeComment((v, "%s", pIdx->zName));
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, 0,
        (char *)pKey, P4_KEYINFO_HANDOFF);
    nCol = pIdx->nColumn;
    if( iMem+nCol*2>=pParse->nMem ){
      pParse->nMem = iMem+nCol*2+1;
    }
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, iIdxCur, nCol+1);

    /* Memory cells are used as follows:
    **
    **    mem[iMem]:             The total number of rows in the table.
    **    mem[iMem+1]:           Number of distinct values in column 1
    **    ...
    **    mem[iMem+nCol]:        Number of distinct values in column N
................................................................................
    **    ...
    **    mem[iMem+nCol+nCol]:   Last observed value of column N
    **
    ** Cells iMem through iMem+nCol are initialized to 0.  The others
    ** are initialized to NULL.
    */
    for(i=0; i<=nCol; i++){
      sqlite3VdbeAddOp2(v, OP_MemInt, 0, iMem+i);
    }
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp2(v, OP_MemNull, 0, iMem+nCol+i+1);
    }

    /* Do the analysis.
    */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_MemIncr, 1, iMem);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp2(v, OP_Column, iIdxCur, i);
      sqlite3VdbeAddOp1(v, OP_MemLoad, iMem+nCol+i+1);
      sqlite3VdbeAddOp1(v, OP_Ne, 0x100);
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop);
    for(i=0; i<nCol; i++){
      addr = sqlite3VdbeAddOp2(v, OP_MemIncr, 1, iMem+i+1);
      sqlite3VdbeChangeP2(v, topOfLoop + 3*i + 3, addr);
      sqlite3VdbeAddOp2(v, OP_Column, iIdxCur, i);
      sqlite3VdbeAddOp2(v, OP_MemStore, iMem+nCol+i+1, 1);
    }
    sqlite3VdbeResolveLabel(v, endOfLoop);
    sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
    sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);

    /* Store the results.  
    **
    ** The result is a single row of the sqlite_stat1 table.  The first
    ** two columns are the names of the table and index.  The third column
    ** is a string composed of a list of integer statistics about the
    ** index.  The first integer in the list is the total number of entires
................................................................................
    **
    **        I = (K+D-1)/D
    **
    ** If K==0 then no entry is made into the sqlite_stat1 table.  
    ** If K>0 then it is always the case the D>0 so division by zero
    ** is never possible.
    */
    sqlite3VdbeAddOp1(v, OP_MemLoad, iMem);
    addr = sqlite3VdbeAddOp0(v, OP_IfNot);
    sqlite3VdbeAddOp1(v, OP_NewRowid, iStatCur);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pIdx->zName, 0);
    sqlite3VdbeAddOp1(v, OP_MemLoad, iMem);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, " ", 0);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp1(v, OP_MemLoad, iMem);
      sqlite3VdbeAddOp1(v, OP_MemLoad, iMem+i+1);
      sqlite3VdbeAddOp0(v, OP_Add);
      sqlite3VdbeAddOp1(v, OP_AddImm, -1);
      sqlite3VdbeAddOp1(v, OP_MemLoad, iMem+i+1);
      sqlite3VdbeAddOp0(v, OP_Divide);
      sqlite3VdbeAddOp0(v, OP_ToInt);
      if( i==nCol-1 ){
        sqlite3VdbeAddOp1(v, OP_Concat, nCol*2-1);
      }else{
        sqlite3VdbeAddOp1(v, OP_Dup, 1);
      }
    }
    sqlite3VdbeAddOp4(v, OP_MakeRecord, 3, 0, 0, "aaa", 0);
    sqlite3VdbeAddOp2(v, OP_Insert, iStatCur, OPFLAG_APPEND);
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Generate code that will cause the most recent index analysis to
** be laoded into internal hash tables where is can be used.
*/
static void loadAnalysis(Parse *pParse, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb);
  }
}

/*
** Generate code that will do an analysis of an entire database
*/
static void analyzeDatabase(Parse *pParse, int iDb){

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.64 2007/12/27 15:12:17 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
................................................................................
  v = sqlite3GetVdbe(pParse);
  sqlite3ExprCode(pParse, pFilename);
  sqlite3ExprCode(pParse, pDbname);
  sqlite3ExprCode(pParse, pKey);

  assert( v || db->mallocFailed );
  if( v ){
    sqlite3VdbeAddOp(v, OP_Function, 0, nFunc);
    pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
    sqlite3VdbeChangeP3(v, -1, (char *)pFunc, P3_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing
    ** statements).
    */
    sqlite3VdbeAddOp(v, OP_Expire, (type==SQLITE_ATTACH), 0);
  }
  
attach_end:
  sqlite3ExprDelete(pFilename);
  sqlite3ExprDelete(pDbname);
  sqlite3ExprDelete(pKey);
}

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the ATTACH and DETACH commands.
**
** $Id: attach.c,v 1.65 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
................................................................................
  v = sqlite3GetVdbe(pParse);
  sqlite3ExprCode(pParse, pFilename);
  sqlite3ExprCode(pParse, pDbname);
  sqlite3ExprCode(pParse, pKey);

  assert( v || db->mallocFailed );
  if( v ){
    sqlite3VdbeAddOp2(v, OP_Function, 0, nFunc);
    pFunc = sqlite3FindFunction(db, zFunc, strlen(zFunc), nFunc, SQLITE_UTF8,0);
    sqlite3VdbeChangeP4(v, -1, (char *)pFunc, P4_FUNCDEF);

    /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
    ** statement only). For DETACH, set it to false (expire all existing
    ** statements).
    */
    sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
  }
  
attach_end:
  sqlite3ExprDelete(pFilename);
  sqlite3ExprDelete(pDbname);
  sqlite3ExprDelete(pKey);
}

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.452 2008/01/02 16:27:10 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................

  for(i=0; i<pParse->nTableLock; i++){
    TableLock *p = &pParse->aTableLock[i];
    int p1 = p->iDb;
    if( p->isWriteLock ){
      p1 = -1*(p1+1);
    }
    sqlite3VdbeOp3(pVdbe, OP_TableLock, p1, p->iTab, p->zName, P3_STATIC);
  }
}
#else
  #define codeTableLocks(x)
#endif

/*
................................................................................
  }

  /* Begin by generating some termination code at the end of the
  ** vdbe program
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_Halt, 0, 0);

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
................................................................................
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeUsesBtree(v, iDb);
        sqlite3VdbeAddOp(v, OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp(v, OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      if( pParse->pVirtualLock ){
        char *vtab = (char *)pParse->pVirtualLock->pVtab;
        sqlite3VdbeOp3(v, OP_VBegin, 0, 0, vtab, P3_VTAB);
      }
#endif

      /* Once all the cookies have been verified and transactions opened, 
      ** obtain the required table-locks. This is a no-op unless the 
      ** shared-cache feature is enabled.
      */
      codeTableLocks(pParse);
      sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->cookieGoto);
    }

#ifndef SQLITE_OMIT_TRACE
    /* Add a No-op that contains the complete text of the compiled SQL
    ** statement as its P3 argument.  This does not change the functionality
    ** of the program. 
    **
    ** This is used to implement sqlite3_trace().
    */

    sqlite3VdbeOp3(v, OP_Noop, 0, 0, pParse->zSql, pParse->zTail-pParse->zSql);
#endif /* SQLITE_OMIT_TRACE */
  }


  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 && !db->mallocFailed ){
................................................................................
/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, 0, MASTER_ROOT);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, 0, 5); /* sqlite_master has 5 columns */
}

/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db 
** does not exist.
................................................................................
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int lbl;
    int fileFormat;
    sqlite3BeginWriteOperation(pParse, 0, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp(v, OP_VBegin, 0, 0);
    }
#endif

    /* If the file format and encoding in the database have not been set, 
    ** set them now.
    */
    sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 1);   /* file_format */
    sqlite3VdbeUsesBtree(v, iDb);
    lbl = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_If, 0, lbl);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp(v, OP_Integer, fileFormat, 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 1);
    sqlite3VdbeAddOp(v, OP_Integer, ENC(db), 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 4);
    sqlite3VdbeResolveLabel(v, lbl);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left on the top of the stack.
    ** The rowid value is needed by the code that sqlite3EndTable will
    ** generate.
    */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( isView || isVirtual ){
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    }else
#endif
    {
      sqlite3VdbeAddOp(v, OP_CreateTable, iDb, 0);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp(v, OP_NewRowid, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    sqlite3VdbeAddOp(v, OP_Insert, 0, OPFLAG_APPEND);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
  }

  /* Normal (non-error) return. */
  return;

  /* If an error occurs, we jump here */
begin_table_error:
................................................................................
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqlite3ChangeCookie(sqlite3 *db, Vdbe *v, int iDb){
  sqlite3VdbeAddOp(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, 0);
  sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 0);
}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
**
................................................................................
    char *zType;    /* "view" or "table" */
    char *zType2;   /* "VIEW" or "TABLE" */
    char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;

    sqlite3VdbeAddOp(v, OP_Close, 0, 0);

    /* Create the rootpage for the new table and push it onto the stack.
    ** A view has no rootpage, so just push a zero onto the stack for
    ** views.  Initialize zType at the same time.
    */
    if( p->pSelect==0 ){
      /* A regular table */
................................................................................
    ** as a schema-lock must have already been obtained to create it. Since
    ** a schema-lock excludes all other database users, the write-lock would
    ** be redundant.
    */
    if( pSelect ){
      SelectDest dest = {SRT_Table, 1, 0};
      Table *pSelTab;
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
      sqlite3VdbeAddOp(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;
      sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
      sqlite3VdbeAddOp(v, OP_Close, 1, 0);
      if( pParse->nErr==0 ){
        pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSelect);
        if( pSelTab==0 ) return;
        assert( p->aCol==0 );
        p->nCol = pSelTab->nCol;
        p->aCol = pSelTab->aCol;
        pSelTab->nCol = 0;
................................................................................
          pDb->zName
        );
      }
    }
#endif

    /* Reparse everything to update our internal data structures */
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0,
        sqlite3MPrintf(db, "tbl_name='%q'",p->zName), P3_DYNAMIC);
  }


  /* Add the table to the in-memory representation of the database.
  */
  if( db->init.busy && pParse->nErr==0 ){
    Table *pOld;
................................................................................
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  sqlite3VdbeAddOp(v, OP_Destroy, iTable, iDb);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy pushes an integer onto the stack. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_master table to
  ** reflect this.
  **
  ** The "#0" in the SQL is a special constant that means whatever value
................................................................................
    Db *pDb = &db->aDb[iDb];
    sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      Vdbe *v = sqlite3GetVdbe(pParse);
      if( v ){
        sqlite3VdbeAddOp(v, OP_VBegin, 0, 0);
      }
    }
#endif

    /* Drop all triggers associated with the table being dropped. Code
    ** is generated to remove entries from sqlite_master and/or
    ** sqlite_temp_master if required.
................................................................................
      destroyTable(pParse, pTab);
    }

    /* Remove the table entry from SQLite's internal schema and modify
    ** the schema cookie.
    */
    if( IsVirtual(pTab) ){
      sqlite3VdbeOp3(v, OP_VDestroy, iDb, 0, pTab->zName, 0);
    }
    sqlite3VdbeOp3(v, OP_DropTable, iDb, 0, pTab->zName, 0);
    sqlite3ChangeCookie(db, v, iDb);
  }
  sqliteViewResetAll(db, iDb);

exit_drop_table:
  sqlite3SrcListDelete(pName);
}
................................................................................

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){
    sqlite3VdbeAddOp(v, OP_MemLoad, memRootPage, 0);
    tnum = 0;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp(v, OP_Clear, tnum, iDb);
  }
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeOp3(v, OP_OpenWrite, iIdx, tnum, (char *)pKey, P3_KEYINFO_HANDOFF);

  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp(v, OP_Rewind, iTab, 0);
  sqlite3GenerateIndexKey(v, pIndex, iTab);
  if( pIndex->onError!=OE_None ){
    int curaddr = sqlite3VdbeCurrentAddr(v);
    int addr2 = curaddr+4;
    sqlite3VdbeChangeP2(v, curaddr-1, addr2);
    sqlite3VdbeAddOp(v, OP_Rowid, iTab, 0);
    sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
    sqlite3VdbeAddOp(v, OP_IsUnique, iIdx, addr2);
    sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, OE_Abort,
                    "indexed columns are not unique", P3_STATIC);
    assert( db->mallocFailed || addr2==sqlite3VdbeCurrentAddr(v) );
  }
  sqlite3VdbeAddOp(v, OP_IdxInsert, iIdx, 0);
  sqlite3VdbeAddOp(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);
  sqlite3VdbeAddOp(v, OP_Close, iTab, 0);
  sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
................................................................................
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto exit_create_index;


    /* Create the rootpage for the index
    */
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3VdbeAddOp(v, OP_CreateIndex, iDb, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);

    /* Gather the complete text of the CREATE INDEX statement into
    ** the zStmt variable
    */
    if( pStart && pEnd ){
      /* A named index with an explicit CREATE INDEX statement */
      zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
................................................................................
    sqlite3NestedParse(pParse, 
        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#0,%Q);",
        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
        pIndex->zName,
        pTab->zName,
        zStmt
    );
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3_free(zStmt);

    /* Fill the index with data and reparse the schema. Code an OP_Expire
    ** to invalidate all pre-compiled statements.
    */
    if( pTblName ){
      sqlite3RefillIndex(pParse, pIndex, iMem);
      sqlite3ChangeCookie(db, v, iDb);
      sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0,
         sqlite3MPrintf(db, "name='%q'", pIndex->zName), P3_DYNAMIC);
      sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
    }
  }

  /* When adding an index to the list of indices for a table, make
  ** sure all indices labeled OE_Replace come after all those labeled
  ** OE_Ignore.  This is necessary for the correct operation of UPDATE
  ** and INSERT.
................................................................................
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
  Vdbe *v;
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 1);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp(v, OP_Integer, minFormat, 0);
    sqlite3VdbeAddOp(v, OP_Ge, 0, sqlite3VdbeCurrentAddr(v)+3);
    sqlite3VdbeAddOp(v, OP_Integer, minFormat, 0);
    sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 1);
  }
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**
................................................................................
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.%s WHERE name=%Q",
       db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
       pIndex->zName
    );
    sqlite3ChangeCookie(db, v, iDb);
    destroyRootPage(pParse, pIndex->tnum, iDb);
    sqlite3VdbeOp3(v, OP_DropIndex, iDb, 0, pIndex->zName, 0);
  }

exit_drop_index:
  sqlite3SrcListDelete(pName);
}

/*
................................................................................
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
      sqlite3VdbeAddOp(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
      sqlite3VdbeUsesBtree(v, i);
    }
  }
  sqlite3VdbeAddOp(v, OP_AutoCommit, 0, 0);
}

/*
** Commit a transaction
*/
void sqlite3CommitTransaction(Parse *pParse){
  sqlite3 *db;
................................................................................

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 0);
  }
}

/*
** Rollback a transaction
*/
void sqlite3RollbackTransaction(Parse *pParse){
................................................................................

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_AutoCommit, 1, 1);
  }
}

/*
** Make sure the TEMP database is open and available for use.  Return
** the number of errors.  Leave any error messages in the pParse structure.
*/
................................................................................
  Vdbe *v;
  int mask;

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;  /* This only happens if there was a prior error */
  db = pParse->db;
  if( pParse->cookieGoto==0 ){
    pParse->cookieGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<SQLITE_MAX_ATTACHED+2 );
    mask = 1<<iDb;
    if( (pParse->cookieMask & mask)==0 ){
................................................................................
*/
void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  sqlite3CodeVerifySchema(pParse, iDb);
  pParse->writeMask |= 1<<iDb;
  if( setStatement && pParse->nested==0 ){
    sqlite3VdbeAddOp(v, OP_Statement, iDb, 0);
  }
  if( (OMIT_TEMPDB || iDb!=1) && pParse->db->aDb[1].pBt!=0 ){
    sqlite3BeginWriteOperation(pParse, setStatement, 1);
  }
}

/*

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.453 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................

  for(i=0; i<pParse->nTableLock; i++){
    TableLock *p = &pParse->aTableLock[i];
    int p1 = p->iDb;
    if( p->isWriteLock ){
      p1 = -1*(p1+1);
    }
    sqlite3VdbeAddOp4(pVdbe, OP_TableLock, p1, p->iTab, 0, p->zName, P4_STATIC);
  }
}
#else
  #define codeTableLocks(x)
#endif

/*
................................................................................
  }

  /* Begin by generating some termination code at the end of the
  ** vdbe program
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp0(v, OP_Halt);

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
................................................................................
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeUsesBtree(v, iDb);
        sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp2(v,OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      if( pParse->pVirtualLock ){
        char *vtab = (char *)pParse->pVirtualLock->pVtab;
        sqlite3VdbeAddOp4(v, OP_VBegin, 0, 0, 0, vtab, P4_VTAB);
      }
#endif

      /* Once all the cookies have been verified and transactions opened, 
      ** obtain the required table-locks. This is a no-op unless the 
      ** shared-cache feature is enabled.
      */
      codeTableLocks(pParse);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->cookieGoto);
    }

#ifndef SQLITE_OMIT_TRACE
    /* Add a No-op that contains the complete text of the compiled SQL
    ** statement as its P4 argument.  This does not change the functionality
    ** of the program. 
    **
    ** This is used to implement sqlite3_trace().
    */
    sqlite3VdbeAddOp4(v, OP_Noop, 0, 0, 0,
                      pParse->zSql, pParse->zTail-pParse->zSql);
#endif /* SQLITE_OMIT_TRACE */
  }


  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 && !db->mallocFailed ){
................................................................................
/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
  sqlite3VdbeAddOp1(v, OP_Integer, iDb);
  sqlite3VdbeAddOp2(v, OP_OpenWrite, 0, MASTER_ROOT);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, 0, 5); /* sqlite_master has 5 columns */
}

/*
** The token *pName contains the name of a database (either "main" or
** "temp" or the name of an attached db). This routine returns the
** index of the named database in db->aDb[], or -1 if the named db 
** does not exist.
................................................................................
  if( !db->init.busy && (v = sqlite3GetVdbe(pParse))!=0 ){
    int lbl;
    int fileFormat;
    sqlite3BeginWriteOperation(pParse, 0, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( isVirtual ){
      sqlite3VdbeAddOp0(v, OP_VBegin);
    }
#endif

    /* If the file format and encoding in the database have not been set, 
    ** set them now.
    */
    sqlite3VdbeAddOp2(v, OP_ReadCookie, iDb, 1);   /* file_format */
    sqlite3VdbeUsesBtree(v, iDb);
    lbl = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_If, 0, lbl);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp1(v, OP_Integer, fileFormat);
    sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 1);
    sqlite3VdbeAddOp1(v, OP_Integer, ENC(db));
    sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 4);
    sqlite3VdbeResolveLabel(v, lbl);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left on the top of the stack.
    ** The rowid value is needed by the code that sqlite3EndTable will
    ** generate.
    */
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
    if( isView || isVirtual ){
      sqlite3VdbeAddOp0(v, OP_Integer);
    }else
#endif
    {
      sqlite3VdbeAddOp1(v, OP_CreateTable, iDb);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp0(v, OP_NewRowid);
    sqlite3VdbeAddOp0(v, OP_Dup);
    sqlite3VdbeAddOp0(v, OP_Null);
    sqlite3VdbeAddOp2(v, OP_Insert, 0, OPFLAG_APPEND);
    sqlite3VdbeAddOp0(v, OP_Close);
    sqlite3VdbeAddOp1(v, OP_Pull, 1);
  }

  /* Normal (non-error) return. */
  return;

  /* If an error occurs, we jump here */
begin_table_error:
................................................................................
** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqlite3ChangeCookie(sqlite3 *db, Vdbe *v, int iDb){
  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, 0);
  sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 0);
}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
**
................................................................................
    char *zType;    /* "view" or "table" */
    char *zType2;   /* "VIEW" or "TABLE" */
    char *zStmt;    /* Text of the CREATE TABLE or CREATE VIEW statement */

    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;

    sqlite3VdbeAddOp1(v, OP_Close, 0);

    /* Create the rootpage for the new table and push it onto the stack.
    ** A view has no rootpage, so just push a zero onto the stack for
    ** views.  Initialize zType at the same time.
    */
    if( p->pSelect==0 ){
      /* A regular table */
................................................................................
    ** as a schema-lock must have already been obtained to create it. Since
    ** a schema-lock excludes all other database users, the write-lock would
    ** be redundant.
    */
    if( pSelect ){
      SelectDest dest = {SRT_Table, 1, 0};
      Table *pSelTab;
      sqlite3VdbeAddOp1(v, OP_Dup, 0);
      sqlite3VdbeAddOp1(v, OP_Integer, iDb);
      sqlite3VdbeAddOp2(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;
      sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
      sqlite3VdbeAddOp1(v, OP_Close, 1);
      if( pParse->nErr==0 ){
        pSelTab = sqlite3ResultSetOfSelect(pParse, 0, pSelect);
        if( pSelTab==0 ) return;
        assert( p->aCol==0 );
        p->nCol = pSelTab->nCol;
        p->aCol = pSelTab->aCol;
        pSelTab->nCol = 0;
................................................................................
          pDb->zName
        );
      }
    }
#endif

    /* Reparse everything to update our internal data structures */
    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
        sqlite3MPrintf(db, "tbl_name='%q'",p->zName), P4_DYNAMIC);
  }


  /* Add the table to the in-memory representation of the database.
  */
  if( db->init.busy && pParse->nErr==0 ){
    Table *pOld;
................................................................................
** Write code to erase the table with root-page iTable from database iDb.
** Also write code to modify the sqlite_master table and internal schema
** if a root-page of another table is moved by the btree-layer whilst
** erasing iTable (this can happen with an auto-vacuum database).
*/ 
static void destroyRootPage(Parse *pParse, int iTable, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  sqlite3VdbeAddOp2(v, OP_Destroy, iTable, iDb);
#ifndef SQLITE_OMIT_AUTOVACUUM
  /* OP_Destroy pushes an integer onto the stack. If this integer
  ** is non-zero, then it is the root page number of a table moved to
  ** location iTable. The following code modifies the sqlite_master table to
  ** reflect this.
  **
  ** The "#0" in the SQL is a special constant that means whatever value
................................................................................
    Db *pDb = &db->aDb[iDb];
    sqlite3BeginWriteOperation(pParse, 1, iDb);

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      Vdbe *v = sqlite3GetVdbe(pParse);
      if( v ){
        sqlite3VdbeAddOp0(v, OP_VBegin);
      }
    }
#endif

    /* Drop all triggers associated with the table being dropped. Code
    ** is generated to remove entries from sqlite_master and/or
    ** sqlite_temp_master if required.
................................................................................
      destroyTable(pParse, pTab);
    }

    /* Remove the table entry from SQLite's internal schema and modify
    ** the schema cookie.
    */
    if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp4(v, OP_VDestroy, iDb, 0, 0, pTab->zName, 0);
    }
    sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);
    sqlite3ChangeCookie(db, v, iDb);
  }
  sqliteViewResetAll(db, iDb);

exit_drop_table:
  sqlite3SrcListDelete(pName);
}
................................................................................

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){
    sqlite3VdbeAddOp1(v, OP_MemLoad, memRootPage);
    tnum = 0;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp2(v, OP_Clear, tnum, iDb);
  }
  sqlite3VdbeAddOp1(v, OP_Integer, iDb);
  pKey = sqlite3IndexKeyinfo(pParse, pIndex);
  sqlite3VdbeAddOp4(v, OP_OpenWrite, iIdx, tnum, 0, 
                    (char *)pKey, P4_KEYINFO_HANDOFF);
  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
  sqlite3GenerateIndexKey(v, pIndex, iTab);
  if( pIndex->onError!=OE_None ){
    int curaddr = sqlite3VdbeCurrentAddr(v);
    int addr2 = curaddr+4;
    sqlite3VdbeChangeP2(v, curaddr-1, addr2);
    sqlite3VdbeAddOp1(v, OP_Rowid, iTab);
    sqlite3VdbeAddOp1(v, OP_AddImm, 1);
    sqlite3VdbeAddOp2(v, OP_IsUnique, iIdx, addr2);
    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, OE_Abort, 0,
                    "indexed columns are not unique", P4_STATIC);
    assert( db->mallocFailed || addr2==sqlite3VdbeCurrentAddr(v) );
  }
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iIdx, 0);
  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);
  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 
** be NULL for a primary key or an index that is created to satisfy a
** UNIQUE constraint.  If pTable and pIndex are NULL, use pParse->pNewTable
................................................................................
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto exit_create_index;


    /* Create the rootpage for the index
    */
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3VdbeAddOp1(v, OP_CreateIndex, iDb);
    sqlite3VdbeAddOp2(v, OP_MemStore, iMem, 0);

    /* Gather the complete text of the CREATE INDEX statement into
    ** the zStmt variable
    */
    if( pStart && pEnd ){
      /* A named index with an explicit CREATE INDEX statement */
      zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
................................................................................
    sqlite3NestedParse(pParse, 
        "INSERT INTO %Q.%s VALUES('index',%Q,%Q,#0,%Q);",
        db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
        pIndex->zName,
        pTab->zName,
        zStmt
    );
    sqlite3VdbeAddOp1(v, OP_Pop, 1);
    sqlite3_free(zStmt);

    /* Fill the index with data and reparse the schema. Code an OP_Expire
    ** to invalidate all pre-compiled statements.
    */
    if( pTblName ){
      sqlite3RefillIndex(pParse, pIndex, iMem);
      sqlite3ChangeCookie(db, v, iDb);
      sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
         sqlite3MPrintf(db, "name='%q'", pIndex->zName), P4_DYNAMIC);
      sqlite3VdbeAddOp1(v, OP_Expire, 0);
    }
  }

  /* When adding an index to the list of indices for a table, make
  ** sure all indices labeled OE_Replace come after all those labeled
  ** OE_Ignore.  This is necessary for the correct operation of UPDATE
  ** and INSERT.
................................................................................
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){
  Vdbe *v;
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp2(v, OP_ReadCookie, iDb, 1);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp1(v, OP_Integer, minFormat);
    sqlite3VdbeAddOp2(v, OP_Ge, 0, sqlite3VdbeCurrentAddr(v)+3);
    sqlite3VdbeAddOp1(v, OP_Integer, minFormat);
    sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 1);
  }
}

/*
** Fill the Index.aiRowEst[] array with default information - information
** to be used when we have not run the ANALYZE command.
**
................................................................................
    sqlite3NestedParse(pParse,
       "DELETE FROM %Q.%s WHERE name=%Q",
       db->aDb[iDb].zName, SCHEMA_TABLE(iDb),
       pIndex->zName
    );
    sqlite3ChangeCookie(db, v, iDb);
    destroyRootPage(pParse, pIndex->tnum, iDb);
    sqlite3VdbeAddOp4(v, OP_DropIndex, iDb, 0, 0, pIndex->zName, 0);
  }

exit_drop_index:
  sqlite3SrcListDelete(pName);
}

/*
................................................................................
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "BEGIN", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
      sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
      sqlite3VdbeUsesBtree(v, i);
    }
  }
  sqlite3VdbeAddOp2(v, OP_AutoCommit, 0, 0);
}

/*
** Commit a transaction
*/
void sqlite3CommitTransaction(Parse *pParse){
  sqlite3 *db;
................................................................................

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "COMMIT", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 0);
  }
}

/*
** Rollback a transaction
*/
void sqlite3RollbackTransaction(Parse *pParse){
................................................................................

  if( pParse==0 || (db=pParse->db)==0 || db->aDb[0].pBt==0 ) return;
  if( pParse->nErr || db->mallocFailed ) return;
  if( sqlite3AuthCheck(pParse, SQLITE_TRANSACTION, "ROLLBACK", 0, 0) ) return;

  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp2(v, OP_AutoCommit, 1, 1);
  }
}

/*
** Make sure the TEMP database is open and available for use.  Return
** the number of errors.  Leave any error messages in the pParse structure.
*/
................................................................................
  Vdbe *v;
  int mask;

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;  /* This only happens if there was a prior error */
  db = pParse->db;
  if( pParse->cookieGoto==0 ){
    pParse->cookieGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0)+1;
  }
  if( iDb>=0 ){
    assert( iDb<db->nDb );
    assert( db->aDb[iDb].pBt!=0 || iDb==1 );
    assert( iDb<SQLITE_MAX_ATTACHED+2 );
    mask = 1<<iDb;
    if( (pParse->cookieMask & mask)==0 ){
................................................................................
*/
void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  sqlite3CodeVerifySchema(pParse, iDb);
  pParse->writeMask |= 1<<iDb;
  if( setStatement && pParse->nested==0 ){
    sqlite3VdbeAddOp1(v, OP_Statement, iDb);
  }
  if( (OMIT_TEMPDB || iDb!=1) && pParse->db->aDb[1].pBt!=0 ){
    sqlite3BeginWriteOperation(pParse, setStatement, 1);
  }
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.139 2008/01/02 16:27:10 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  if( IsVirtual(pTab) ) return;
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  VdbeComment((v, "%s", pTab->zName));
  sqlite3VdbeAddOp(v, opcode, iCur, pTab->tnum);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
}


/*
** Generate code for a DELETE FROM statement.
**
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
................................................................................
  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);

  if( triggers_exist ){
    int iGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
        -1, oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
        addr, &old_col_mask, 0);
    iEndBeforeTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
        oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
        addr, &old_col_mask, 0);
    iEndAfterTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.
  */
  if( isView ){
................................................................................
  }

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
    memCnt = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt);
  }

  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.  Note, however, that
  ** this means that the row change count will be incorrect.
  */
  if( pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
................................................................................
    if( db->flags & SQLITE_CountRows ){
      /* If counting rows deleted, just count the total number of
      ** entries in the table. */
      int addr2;
      if( !isView ){
        sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
      }
      sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
      addr2 = sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
      sqlite3VdbeAddOp(v, OP_Next, iCur, addr2);
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    }
    if( !isView ){
      sqlite3VdbeAddOp(v, OP_Clear, pTab->tnum, iDb);
      if( !pParse->nested ){
        sqlite3VdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
      }
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        assert( pIdx->pSchema==pTab->pSchema );
        sqlite3VdbeAddOp(v, OP_Clear, pIdx->tnum, iDb);
      }
    }
  } 
  /* The usual case: There is a WHERE clause so we have to scan through
  ** the table and pick which records to delete.
  */
  else{
................................................................................
    /* Begin the database scan
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
    if( pWInfo==0 ) goto delete_from_cleanup;

    /* Remember the rowid of every item to be deleted.
    */
    sqlite3VdbeAddOp(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0);
    sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0);
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
    }

    /* End the database scan loop.
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( triggers_exist ){
      sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    end = sqlite3VdbeMakeLabel(v);
................................................................................

    /* This is the beginning of the delete loop. If a trigger encounters
    ** an IGNORE constraint, it jumps back to here.
    */
    if( triggers_exist ){
      sqlite3VdbeResolveLabel(v, addr);
    }
    addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, end);
    sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);

    if( triggers_exist ){
      int mem1 = pParse->nMem++;
      if( !isView ){
        sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
      }
      sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
      sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
      if( old_col_mask ){
        sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
      }else{
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      }
      sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);

      /* Jump back and run the BEFORE triggers */
      sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginBeforeTrigger);
      sqlite3VdbeJumpHere(v, iEndBeforeTrigger);

      if( !isView ){
        sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
      }
    }

    if( !isView ){
      /* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
      if( IsVirtual(pTab) ){
        pParse->pVirtualLock = pTab;

        sqlite3VdbeOp3(v, OP_VUpdate, 0, 1, (const char*)pTab->pVtab, P3_VTAB);
      }else
#endif
      {
        sqlite3GenerateRowDelete(db, v, pTab, iCur, pParse->nested==0);
      }
    }

    /* If there are row triggers, close all cursors then invoke
    ** the AFTER triggers
    */
    if( triggers_exist ){
      /* Jump back and run the AFTER triggers */
      sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginAfterTrigger);
      sqlite3VdbeJumpHere(v, iEndAfterTrigger);
    }

    /* End of the delete loop */
    sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
    sqlite3VdbeResolveLabel(v, end);

    /* Close the cursors after the loop if there are no row triggers */
    if( !isView  && !IsVirtual(pTab) ){
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
      }
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    }
  }

  /*
  ** Return the number of rows that were deleted. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
    sqlite3VdbeAddOp(v, OP_ResultRow, memCnt, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", P3_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(pTabList);
  sqlite3ExprDelete(pWhere);
  return;
................................................................................
  sqlite3 *db,       /* The database containing the index */
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  int count          /* Increment the row change counter */
){
  int addr;
  addr = sqlite3VdbeAddOp(v, OP_NotExists, iCur, 0);
  sqlite3GenerateRowIndexDelete(v, pTab, iCur, 0);
  sqlite3VdbeAddOp(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
  if( count ){
    sqlite3VdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
  }
  sqlite3VdbeJumpHere(v, addr);
}

/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table.
................................................................................
){
  int i;
  Index *pIdx;

  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    if( aIdxUsed!=0 && aIdxUsed[i-1]==0 ) continue;
    sqlite3GenerateIndexKey(v, pIdx, iCur);
    sqlite3VdbeAddOp(v, OP_IdxDelete, iCur+i, 0);
  }
}

/*
** Generate code that will assemble an index key and put it on the top
** of the tack.  The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
................................................................................
  Vdbe *v,           /* Generate code into this VDBE */
  Index *pIdx,       /* The index for which to generate a key */
  int iCur           /* Cursor number for the pIdx->pTable table */
){
  int j;
  Table *pTab = pIdx->pTable;

  sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
  for(j=0; j<pIdx->nColumn; j++){
    int idx = pIdx->aiColumn[j];
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp(v, OP_Dup, j, 0);
    }else{
      sqlite3VdbeAddOp(v, OP_Column, iCur, idx);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  sqlite3VdbeAddOp(v, OP_MakeIdxRec, pIdx->nColumn, 0);
  sqlite3IndexAffinityStr(v, pIdx);
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.140 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.
................................................................................
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v;
  if( IsVirtual(pTab) ) return;
  v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
  sqlite3VdbeAddOp1(v, OP_Integer, iDb);
  VdbeComment((v, "%s", pTab->zName));
  sqlite3VdbeAddOp2(v, opcode, iCur, pTab->tnum);
  sqlite3VdbeAddOp2(v, OP_SetNumColumns, iCur, pTab->nCol);
}


/*
** Generate code for a DELETE FROM statement.
**
**     DELETE FROM table_wxyz WHERE a<5 AND b NOT NULL;
................................................................................
  if( v==0 ){
    goto delete_from_cleanup;
  }
  if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
  sqlite3BeginWriteOperation(pParse, triggers_exist, iDb);

  if( triggers_exist ){
    int iGoto = sqlite3VdbeAddOp0(v, OP_Goto);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_BEFORE, pTab,
        -1, oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
        addr, &old_col_mask, 0);
    iEndBeforeTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    (void)sqlite3CodeRowTrigger(pParse, TK_DELETE, 0, TRIGGER_AFTER, pTab, -1,
        oldIdx, (pParse->trigStack)?pParse->trigStack->orconf:OE_Default,
        addr, &old_col_mask, 0);
    iEndAfterTrigger = sqlite3VdbeAddOp0(v, OP_Goto);
    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to delete from a view, realize that view into
  ** a ephemeral table.
  */
  if( isView ){
................................................................................
  }

  /* Initialize the counter of the number of rows deleted, if
  ** we are counting rows.
  */
  if( db->flags & SQLITE_CountRows ){
    memCnt = pParse->nMem++;
    sqlite3VdbeAddOp2(v, OP_MemInt, 0, memCnt);
  }

  /* Special case: A DELETE without a WHERE clause deletes everything.
  ** It is easier just to erase the whole table.  Note, however, that
  ** this means that the row change count will be incorrect.
  */
  if( pWhere==0 && !triggers_exist && !IsVirtual(pTab) ){
................................................................................
    if( db->flags & SQLITE_CountRows ){
      /* If counting rows deleted, just count the total number of
      ** entries in the table. */
      int addr2;
      if( !isView ){
        sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
      }
      sqlite3VdbeAddOp2(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
      addr2 = sqlite3VdbeAddOp2(v, OP_MemIncr, 1, memCnt);
      sqlite3VdbeAddOp2(v, OP_Next, iCur, addr2);
      sqlite3VdbeAddOp1(v, OP_Close, iCur);
    }
    if( !isView ){
      sqlite3VdbeAddOp2(v, OP_Clear, pTab->tnum, iDb);
      if( !pParse->nested ){
        sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
      }
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        assert( pIdx->pSchema==pTab->pSchema );
        sqlite3VdbeAddOp2(v, OP_Clear, pIdx->tnum, iDb);
      }
    }
  } 
  /* The usual case: There is a WHERE clause so we have to scan through
  ** the table and pick which records to delete.
  */
  else{
................................................................................
    /* Begin the database scan
    */
    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
    if( pWInfo==0 ) goto delete_from_cleanup;

    /* Remember the rowid of every item to be deleted.
    */
    sqlite3VdbeAddOp1(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur);
    sqlite3VdbeAddOp0(v, OP_FifoWrite);
    if( db->flags & SQLITE_CountRows ){
      sqlite3VdbeAddOp2(v, OP_MemIncr, 1, memCnt);
    }

    /* End the database scan loop.
    */
    sqlite3WhereEnd(pWInfo);

    /* Open the pseudo-table used to store OLD if there are triggers.
    */
    if( triggers_exist ){
      sqlite3VdbeAddOp1(v, OP_OpenPseudo, oldIdx);
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    }

    /* Delete every item whose key was written to the list during the
    ** database scan.  We have to delete items after the scan is complete
    ** because deleting an item can change the scan order.
    */
    end = sqlite3VdbeMakeLabel(v);
................................................................................

    /* This is the beginning of the delete loop. If a trigger encounters
    ** an IGNORE constraint, it jumps back to here.
    */
    if( triggers_exist ){
      sqlite3VdbeResolveLabel(v, addr);
    }
    addr = sqlite3VdbeAddOp2(v, OP_FifoRead, 0, end);
    sqlite3VdbeAddOp1(v, OP_StackDepth, -1);

    if( triggers_exist ){
      int mem1 = pParse->nMem++;
      if( !isView ){
        sqlite3VdbeAddOp1(v, OP_MemStore, mem1);
      }
      sqlite3VdbeAddOp2(v, OP_NotExists, iCur, addr);
      sqlite3VdbeAddOp1(v, OP_Rowid, iCur);
      if( old_col_mask ){
        sqlite3VdbeAddOp1(v, OP_RowData, iCur);
      }else{
        sqlite3VdbeAddOp0(v, OP_Null);
      }
      sqlite3VdbeAddOp1(v, OP_Insert, oldIdx);

      /* Jump back and run the BEFORE triggers */
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
      sqlite3VdbeJumpHere(v, iEndBeforeTrigger);

      if( !isView ){
        sqlite3VdbeAddOp1(v, OP_MemLoad, mem1);
      }
    }

    if( !isView ){
      /* Delete the row */
#ifndef SQLITE_OMIT_VIRTUALTABLE
      if( IsVirtual(pTab) ){
        pParse->pVirtualLock = pTab;
        sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, 0,
                          (const char*)pTab->pVtab, P4_VTAB);
      }else
#endif
      {
        sqlite3GenerateRowDelete(db, v, pTab, iCur, pParse->nested==0);
      }
    }

    /* If there are row triggers, close all cursors then invoke
    ** the AFTER triggers
    */
    if( triggers_exist ){
      /* Jump back and run the AFTER triggers */
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
      sqlite3VdbeJumpHere(v, iEndAfterTrigger);
    }

    /* End of the delete loop */
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
    sqlite3VdbeResolveLabel(v, end);

    /* Close the cursors after the loop if there are no row triggers */
    if( !isView  && !IsVirtual(pTab) ){
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqlite3VdbeAddOp2(v, OP_Close, iCur + i, pIdx->tnum);
      }
      sqlite3VdbeAddOp1(v, OP_Close, iCur);
    }
  }

  /*
  ** Return the number of rows that were deleted. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
    sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows deleted", P4_STATIC);
  }

delete_from_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3SrcListDelete(pTabList);
  sqlite3ExprDelete(pWhere);
  return;
................................................................................
  sqlite3 *db,       /* The database containing the index */
  Vdbe *v,           /* Generate code into this VDBE */
  Table *pTab,       /* Table containing the row to be deleted */
  int iCur,          /* Cursor number for the table */
  int count          /* Increment the row change counter */
){
  int addr;
  addr = sqlite3VdbeAddOp1(v, OP_NotExists, iCur);
  sqlite3GenerateRowIndexDelete(v, pTab, iCur, 0);
  sqlite3VdbeAddOp2(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
  if( count ){
    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
  }
  sqlite3VdbeJumpHere(v, addr);
}

/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table.
................................................................................
){
  int i;
  Index *pIdx;

  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    if( aIdxUsed!=0 && aIdxUsed[i-1]==0 ) continue;
    sqlite3GenerateIndexKey(v, pIdx, iCur);
    sqlite3VdbeAddOp1(v, OP_IdxDelete, iCur+i);
  }
}

/*
** Generate code that will assemble an index key and put it on the top
** of the tack.  The key with be for index pIdx which is an index on pTab.
** iCur is the index of a cursor open on the pTab table and pointing to
................................................................................
  Vdbe *v,           /* Generate code into this VDBE */
  Index *pIdx,       /* The index for which to generate a key */
  int iCur           /* Cursor number for the pIdx->pTable table */
){
  int j;
  Table *pTab = pIdx->pTable;

  sqlite3VdbeAddOp1(v, OP_Rowid, iCur);
  for(j=0; j<pIdx->nColumn; j++){
    int idx = pIdx->aiColumn[j];
    if( idx==pTab->iPKey ){
      sqlite3VdbeAddOp1(v, OP_Dup, j);
    }else{
      sqlite3VdbeAddOp2(v, OP_Column, iCur, idx);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  sqlite3VdbeAddOp1(v, OP_MakeIdxRec, pIdx->nColumn);
  sqlite3IndexAffinityStr(v, pIdx);
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.324 2008/01/02 16:27:10 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
  Expr *pRight,     /* The right operand */
  int opcode,       /* The comparison opcode */
  int dest,         /* Jump here if true.  */
  int jumpIfNull    /* If true, jump if either operand is NULL */
){
  int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
  CollSeq *p3 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
  return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (void*)p3, P3_COLLSEQ);

}

/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqlite3_malloc().  The calling function
** is responsible for making sure the node eventually gets freed.
*/
................................................................................
  if( v==0 ) return 0;
  p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
  if( p==0 ){
    return 0;  /* Malloc failed */
  }
  depth = atoi((char*)&pToken->z[1]);
  p->iTable = pParse->nMem++;
  sqlite3VdbeAddOp(v, OP_Dup, depth, 0);
  sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1);
  return p;
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
*/
................................................................................
    if( iCol<0 ){
      int iMem = pParse->nMem++;
      int iAddr;
      Table *pTab = p->pSrc->a[0].pTab;
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeUsesBtree(v, iDb);

      sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
      iAddr = sqlite3VdbeAddOp(v, OP_If, 0, iMem);
      sqlite3VdbeAddOp(v, OP_MemInt, 1, iMem);

      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
      eType = IN_INDEX_ROWID;

      sqlite3VdbeJumpHere(v, iAddr);
    }else{
      /* The collation sequence used by the comparison. If an index is to 
................................................................................
          int iAddr;
          char *pKey;
  
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
          sqlite3VdbeUsesBtree(v, iDb);

          sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
          iAddr = sqlite3VdbeAddOp(v, OP_If, 0, iMem);
          sqlite3VdbeAddOp(v, OP_MemInt, 1, iMem);
  
          sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
          VdbeComment((v, "%s", pIdx->zName));

          sqlite3VdbeOp3(v,OP_OpenRead,iTab,pIdx->tnum,pKey,P3_KEYINFO_HANDOFF);
          eType = IN_INDEX_INDEX;
          sqlite3VdbeAddOp(v, OP_SetNumColumns, iTab, pIdx->nColumn);

          sqlite3VdbeJumpHere(v, iAddr);
        }
      }
    }
  }

................................................................................
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
    testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
    assert( testAddr>0 || pParse->db->mallocFailed );
    sqlite3VdbeAddOp(v, OP_MemInt, 1, mem);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;
      int addr;        /* Address of OP_OpenEphemeral instruction */
................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, pExpr->iTable, 0);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;
      sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);

      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
................................................................................
          if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 3);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2);
          sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);
          sqlite3VdbeAddOp(v, OP_IdxInsert, pExpr->iTable, 0);
        }
      }
      sqlite3VdbeChangeP3(v, addr, (void *)&keyInfo, P3_KEYINFO);
      break;
    }

    case TK_EXISTS:
    case TK_SELECT: {
      /* This has to be a scalar SELECT.  Generate code to put the
      ** value of this select in a memory cell and record the number
................................................................................
      Select *pSel;
      SelectDest dest;

      pSel = pExpr->pSelect;
      dest.iParm = pParse->nMem++;
      if( pExpr->op==TK_SELECT ){
        dest.eDest = SRT_Mem;
        sqlite3VdbeAddOp(v, OP_MemNull, 0, dest.iParm);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp(v, OP_MemInt, 0, dest.iParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      sqlite3ExprDelete(pSel->pLimit);
      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
      if( sqlite3Select(pParse, pSel, &dest, 0, 0, 0, 0) ){
        return;
      }
................................................................................
  if( z ){
    double value;
    char *zV;
    assert( !isdigit(z[n]) );
    sqlite3AtoF(z, &value);
    if( negateFlag ) value = -value;
    zV = dup8bytes(v, (char*)&value);
    sqlite3VdbeOp3(v, OP_Real, 0, 0, zV, P3_REAL);
  }
}


/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
................................................................................
static void codeInteger(Vdbe *v, const char *z, int n, int negateFlag){
  assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
  if( z ){
    int i;
    assert( !isdigit(z[n]) );
    if( sqlite3GetInt32(z, &i) ){
      if( negateFlag ) i = -i;
      sqlite3VdbeAddOp(v, OP_Integer, i, 0);
    }else if( sqlite3FitsIn64Bits(z, negateFlag) ){
      i64 value;
      char *zV;
      sqlite3Atoi64(z, &value);
      if( negateFlag ) value = -value;
      zV = dup8bytes(v, (char*)&value);
      sqlite3VdbeOp3(v, OP_Int64, 0, 0, zV, P3_INT64);
    }else{
      codeReal(v, z, n, negateFlag);
    }
  }
}


................................................................................
** table pTab and push that column value on the stack.  There
** is an open cursor to pTab in iTable.  If iColumn<0 then
** code is generated that extracts the rowid.
*/
void sqlite3ExprCodeGetColumn(Vdbe *v, Table *pTab, int iColumn, int iTable){
  if( iColumn<0 ){
    int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
    sqlite3VdbeAddOp(v, op, iTable, 0);
  }else if( pTab==0 ){
    sqlite3VdbeAddOp(v, OP_Column, iTable, iColumn);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite3VdbeAddOp(v, op, iTable, iColumn);
    sqlite3ColumnDefault(v, pTab, iColumn);
#ifndef SQLITE_OMIT_FLOATING_POINT
    if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
      sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
    }
#endif
  }
}

/*
** Generate code into the current Vdbe to evaluate the given
................................................................................
void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
  Vdbe *v = pParse->pVdbe;
  int op;
  int stackChng = 1;    /* Amount of change to stack depth */

  if( v==0 ) return;
  if( pExpr==0 ){
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    return;
  }
  op = pExpr->op;
  switch( op ){
    case TK_AGG_COLUMN: {
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0);
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx,
                              pCol->iSorterColumn);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        assert( pParse->ckOffset>0 );
        sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
      }else{
        sqlite3ExprCodeGetColumn(v, pExpr->pTab, pExpr->iColumn, pExpr->iTable);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, (char*)pExpr->token.z, pExpr->token.n, 0);
................................................................................
    }
    case TK_FLOAT: {
      codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0);
      break;
    }
    case TK_STRING: {
      sqlite3DequoteExpr(pParse->db, pExpr);

      sqlite3VdbeOp3(v,OP_String8, 0, 0, (char*)pExpr->token.z, pExpr->token.n);
      break;
    }
    case TK_NULL: {
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      break;
    }
#ifndef SQLITE_OMIT_BLOB_LITERAL
    case TK_BLOB: {
      int n;
      const char *z;
      assert( TK_BLOB==OP_HexBlob );
      n = pExpr->token.n - 3;
      z = (char*)pExpr->token.z + 2;
      assert( n>=0 );
      if( n==0 ){
        z = "";
      }
      sqlite3VdbeOp3(v, op, 0, 0, z, n);
      break;
    }
#endif
    case TK_VARIABLE: {
      sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
      if( pExpr->token.n>1 ){
        sqlite3VdbeChangeP3(v, -1, (char*)pExpr->token.z, pExpr->token.n);
      }
      break;
    }
    case TK_REGISTER: {
      sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0);
      break;
    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      int aff, to_op;
      sqlite3ExprCode(pParse, pExpr->pLeft);
................................................................................
      aff = sqlite3AffinityType(&pExpr->token);
      to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
      assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
      assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
      assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
      assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
      assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
      sqlite3VdbeAddOp(v, to_op, 0, 0);
      stackChng = 0;
      break;
    }
#endif /* SQLITE_OMIT_CAST */
    case TK_LT:
    case TK_LE:
    case TK_GT:
................................................................................
      assert( TK_BITOR==OP_BitOr );
      assert( TK_SLASH==OP_Divide );
      assert( TK_LSHIFT==OP_ShiftLeft );
      assert( TK_RSHIFT==OP_ShiftRight );
      assert( TK_CONCAT==OP_Concat );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      sqlite3VdbeAddOp(v, op, 0, 0);
      stackChng = -1;
      break;
    }
    case TK_UMINUS: {
      Expr *pLeft = pExpr->pLeft;
      assert( pLeft );
      if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
................................................................................
      /* Fall through into TK_NOT */
    }
    case TK_BITNOT:
    case TK_NOT: {
      assert( TK_BITNOT==OP_BitNot );
      assert( TK_NOT==OP_Not );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 0, 0);
      stackChng = 0;
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      int dest;
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
      sqlite3ExprCode(pParse, pExpr->pLeft);
      dest = sqlite3VdbeCurrentAddr(v) + 2;
      sqlite3VdbeAddOp(v, op, 1, dest);
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
      stackChng = 0;
      break;
    }
    case TK_AGG_FUNCTION: {
      AggInfo *pInfo = pExpr->pAggInfo;
      if( pInfo==0 ){
        sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
            &pExpr->span);
      }else{
        sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0);
      }
      break;
    }
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pList = pExpr->pList;
      int nExpr = pList ? pList->nExpr : 0;
................................................................................
        }
        if( pDef->needCollSeq && !pColl ){
          pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
        }
      }
      if( pDef->needCollSeq ){
        if( !pColl ) pColl = pParse->db->pDfltColl; 
        sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
      }
      sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF);

      stackChng = 1-nExpr;
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      if( pExpr->iColumn==0 ){
        sqlite3CodeSubselect(pParse, pExpr);
      }
      sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
      VdbeComment((v, "load subquery result"));
      break;
    }
    case TK_IN: {
      int addr;
      char affinity;
      int ckOffset = pParse->ckOffset;
................................................................................
      int eType;
      int iLabel = sqlite3VdbeMakeLabel(v);

      eType = sqlite3FindInIndex(pParse, pExpr, 0);

      /* Figure out the affinity to use to create a key from the results
      ** of the expression. affinityStr stores a static string suitable for
      ** P3 of OP_MakeRecord.
      */
      affinity = comparisonAffinity(pExpr);

      sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
      pParse->ckOffset = (ckOffset ? (ckOffset+1) : 0);

      /* Code the <expr> from "<expr> IN (...)". The temporary table
      ** pExpr->iTable contains the values that make up the (...) set.
      */
      sqlite3ExprCode(pParse, pExpr->pLeft);
      addr = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4);            /* addr + 0 */
      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, iLabel);
      if( eType==IN_INDEX_ROWID ){
        int iAddr = sqlite3VdbeCurrentAddr(v)+3;
        sqlite3VdbeAddOp(v, OP_MustBeInt, 1, iAddr);
        sqlite3VdbeAddOp(v, OP_NotExists, pExpr->iTable, iAddr);
        sqlite3VdbeAddOp(v, OP_Goto, pExpr->iTable, iLabel);
      }else{

        sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);   /* addr + 4 */
        sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, iLabel);
      }
      sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);                  /* addr + 6 */

      sqlite3VdbeResolveLabel(v, iLabel);

      break;
    }
#endif
    case TK_BETWEEN: {
      Expr *pLeft = pExpr->pLeft;
      struct ExprList_item *pLItem = pExpr->pList->a;
      Expr *pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      pLItem++;
      pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
      sqlite3VdbeAddOp(v, OP_And, 0, 0);
      break;
    }
    case TK_UPLUS: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      stackChng = 0;
      break;
    }
................................................................................
      expr_end_label = sqlite3VdbeMakeLabel(v);
      if( pExpr->pLeft ){
        sqlite3ExprCode(pParse, pExpr->pLeft);
      }
      for(i=0; i<nExpr; i=i+2){
        sqlite3ExprCode(pParse, aListelem[i].pExpr);
        if( pExpr->pLeft ){
          sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
          jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
                                 OP_Ne, 0, 1);
          sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
        }else{
          jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
        }
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
        sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
        sqlite3VdbeJumpHere(v, jumpInst);
      }
      if( pExpr->pLeft ){
        sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      }
      if( pExpr->pRight ){
        sqlite3ExprCode(pParse, pExpr->pRight);
      }else{
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      }
      sqlite3VdbeResolveLabel(v, expr_end_label);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      if( !pParse->trigStack ){
................................................................................
        return;
      }
      if( pExpr->iColumn!=OE_Ignore ){
         assert( pExpr->iColumn==OE_Rollback ||
                 pExpr->iColumn == OE_Abort ||
                 pExpr->iColumn == OE_Fail );
         sqlite3DequoteExpr(pParse->db, pExpr);
         sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
                        (char*)pExpr->token.z, pExpr->token.n);
      } else {
         assert( pExpr->iColumn == OE_Ignore );
         sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
         sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
         VdbeComment((v, "raise(IGNORE)"));
      }
      stackChng = 0;
      break;
    }
#endif
  }
................................................................................
  if( v==0 ) return;
  addr1 = sqlite3VdbeCurrentAddr(v);
  sqlite3ExprCode(pParse, pExpr);
  addr2 = sqlite3VdbeCurrentAddr(v);
  if( addr2>addr1+1
   || ((pOp = sqlite3VdbeGetOp(v, addr1))!=0 && pOp->opcode==OP_Function) ){
    iMem = pExpr->iTable = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
    pExpr->op = TK_REGISTER;
  }
}
#endif

/*
** Generate code to evaluate an expression and store the result in
................................................................................
int sqlite3ExprIntoReg(Parse *pParse, Expr *pExpr, int target){
  Vdbe *v = pParse->pVdbe;
  if( v==0 ) return -1;
  sqlite3ExprCode(pParse, pExpr);
  if( target<0 ){
    target = pParse->nMem++;
  }
  sqlite3VdbeAddOp(v, OP_MemStore, target, 1);
  return target;
}

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
................................................................................
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression "x BETWEEN y AND z" is implemented as:
      **
      ** 1 IF (x < y) GOTO 3
      ** 2 IF (x <= z) GOTO <dest>
      ** 3 ...
      */
      int addr;
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pList->a[0].pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);

      pRight = pExpr->pList->a[1].pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);

      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeJumpHere(v, addr);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
      break;
    }
  }
  pParse->ckOffset = ckOffset;
}

/*
................................................................................
      sqlite3ExprCode(pParse, pExpr->pRight);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression is "x BETWEEN y AND z". It is implemented as:
      **
      ** 1 IF (x >= y) GOTO 3
      ** 2 GOTO <dest>
      ** 3 IF (x > z) GOTO <dest>
      */
      int addr;
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pList->a[0].pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      addr = sqlite3VdbeCurrentAddr(v);
      codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull);

      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, dest);
      pRight = pExpr->pList->a[1].pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
      break;
    }
  }
  pParse->ckOffset = ckOffset;
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.325 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**
................................................................................
  Expr *pRight,     /* The right operand */
  int opcode,       /* The comparison opcode */
  int dest,         /* Jump here if true.  */
  int jumpIfNull    /* If true, jump if either operand is NULL */
){
  int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
  CollSeq *p3 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
  return sqlite3VdbeAddOp4(pParse->pVdbe, opcode, p1, dest, 0,
                           (void*)p3, P4_COLLSEQ);
}

/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqlite3_malloc().  The calling function
** is responsible for making sure the node eventually gets freed.
*/
................................................................................
  if( v==0 ) return 0;
  p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
  if( p==0 ){
    return 0;  /* Malloc failed */
  }
  depth = atoi((char*)&pToken->z[1]);
  p->iTable = pParse->nMem++;
  sqlite3VdbeAddOp1(v, OP_Dup, depth);
  sqlite3VdbeAddOp2(v, OP_MemStore, p->iTable, 1);
  return p;
}

/*
** Join two expressions using an AND operator.  If either expression is
** NULL, then just return the other expression.
*/
................................................................................
    if( iCol<0 ){
      int iMem = pParse->nMem++;
      int iAddr;
      Table *pTab = p->pSrc->a[0].pTab;
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeUsesBtree(v, iDb);

      sqlite3VdbeAddOp1(v, OP_MemLoad, iMem);
      iAddr = sqlite3VdbeAddOp2(v, OP_If, 0, iMem);
      sqlite3VdbeAddOp2(v, OP_MemInt, 1, iMem);

      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
      eType = IN_INDEX_ROWID;

      sqlite3VdbeJumpHere(v, iAddr);
    }else{
      /* The collation sequence used by the comparison. If an index is to 
................................................................................
          int iAddr;
          char *pKey;
  
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
          sqlite3VdbeUsesBtree(v, iDb);

          sqlite3VdbeAddOp1(v, OP_MemLoad, iMem);
          iAddr = sqlite3VdbeAddOp2(v, OP_If, 0, iMem);
          sqlite3VdbeAddOp2(v, OP_MemInt, 1, iMem);
  
          sqlite3VdbeAddOp1(v, OP_Integer, iDb);
          VdbeComment((v, "%s", pIdx->zName));
          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, 0,
                               pKey,P4_KEYINFO_HANDOFF);
          eType = IN_INDEX_INDEX;
          sqlite3VdbeAddOp2(v, OP_SetNumColumns, iTab, pIdx->nColumn);

          sqlite3VdbeJumpHere(v, iAddr);
        }
      }
    }
  }

................................................................................
  **    *  We are inside a trigger
  **
  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp1(v, OP_MemLoad, mem);
    testAddr = sqlite3VdbeAddOp0(v, OP_If);
    assert( testAddr>0 || pParse->db->mallocFailed );
    sqlite3VdbeAddOp2(v, OP_MemInt, 1, mem);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;
      int addr;        /* Address of OP_OpenEphemeral instruction */
................................................................................
      ** column is used to build the index keys. If both 'x' and the
      ** SELECT... statement are columns, then numeric affinity is used
      ** if either column has NUMERIC or INTEGER affinity. If neither
      ** 'x' nor the SELECT... statement are columns, then numeric affinity
      ** is used.
      */
      pExpr->iTable = pParse->nTab++;
      addr = sqlite3VdbeAddOp1(v, OP_OpenEphemeral, pExpr->iTable);
      memset(&keyInfo, 0, sizeof(keyInfo));
      keyInfo.nField = 1;
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, pExpr->iTable, 1);

      if( pExpr->pSelect ){
        /* Case 1:     expr IN (SELECT ...)
        **
        ** Generate code to write the results of the select into the temporary
        ** table allocated and opened above.
        */
................................................................................
          if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 3);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2);
          sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &affinity, 1);
          sqlite3VdbeAddOp1(v, OP_IdxInsert, pExpr->iTable);
        }
      }
      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      break;
    }

    case TK_EXISTS:
    case TK_SELECT: {
      /* This has to be a scalar SELECT.  Generate code to put the
      ** value of this select in a memory cell and record the number
................................................................................
      Select *pSel;
      SelectDest dest;

      pSel = pExpr->pSelect;
      dest.iParm = pParse->nMem++;
      if( pExpr->op==TK_SELECT ){
        dest.eDest = SRT_Mem;
        sqlite3VdbeAddOp2(v, OP_MemNull, 0, dest.iParm);
        VdbeComment((v, "Init subquery result"));
      }else{
        dest.eDest = SRT_Exists;
        sqlite3VdbeAddOp2(v, OP_MemInt, 0, dest.iParm);
        VdbeComment((v, "Init EXISTS result"));
      }
      sqlite3ExprDelete(pSel->pLimit);
      pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
      if( sqlite3Select(pParse, pSel, &dest, 0, 0, 0, 0) ){
        return;
      }
................................................................................
  if( z ){
    double value;
    char *zV;
    assert( !isdigit(z[n]) );
    sqlite3AtoF(z, &value);
    if( negateFlag ) value = -value;
    zV = dup8bytes(v, (char*)&value);
    sqlite3VdbeAddOp4(v, OP_Real, 0, 0, 0, zV, P4_REAL);
  }
}


/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
................................................................................
static void codeInteger(Vdbe *v, const char *z, int n, int negateFlag){
  assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
  if( z ){
    int i;
    assert( !isdigit(z[n]) );
    if( sqlite3GetInt32(z, &i) ){
      if( negateFlag ) i = -i;
      sqlite3VdbeAddOp1(v, OP_Integer, i);
    }else if( sqlite3FitsIn64Bits(z, negateFlag) ){
      i64 value;
      char *zV;
      sqlite3Atoi64(z, &value);
      if( negateFlag ) value = -value;
      zV = dup8bytes(v, (char*)&value);
      sqlite3VdbeAddOp4(v, OP_Int64, 0, 0, 0, zV, P4_INT64);
    }else{
      codeReal(v, z, n, negateFlag);
    }
  }
}


................................................................................
** table pTab and push that column value on the stack.  There
** is an open cursor to pTab in iTable.  If iColumn<0 then
** code is generated that extracts the rowid.
*/
void sqlite3ExprCodeGetColumn(Vdbe *v, Table *pTab, int iColumn, int iTable){
  if( iColumn<0 ){
    int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
    sqlite3VdbeAddOp1(v, op, iTable);
  }else if( pTab==0 ){
    sqlite3VdbeAddOp2(v, OP_Column, iTable, iColumn);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite3VdbeAddOp2(v, op, iTable, iColumn);
    sqlite3ColumnDefault(v, pTab, iColumn);
#ifndef SQLITE_OMIT_FLOATING_POINT
    if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
      sqlite3VdbeAddOp0(v, OP_RealAffinity);
    }
#endif
  }
}

/*
** Generate code into the current Vdbe to evaluate the given
................................................................................
void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
  Vdbe *v = pParse->pVdbe;
  int op;
  int stackChng = 1;    /* Amount of change to stack depth */

  if( v==0 ) return;
  if( pExpr==0 ){
    sqlite3VdbeAddOp0(v, OP_Null);
    return;
  }
  op = pExpr->op;
  switch( op ){
    case TK_AGG_COLUMN: {
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        sqlite3VdbeAddOp1(v, OP_MemLoad, pCol->iMem);
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp2(v, OP_Column, pAggInfo->sortingIdx,
                              pCol->iSorterColumn);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        assert( pParse->ckOffset>0 );
        sqlite3VdbeAddOp2(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
      }else{
        sqlite3ExprCodeGetColumn(v, pExpr->pTab, pExpr->iColumn, pExpr->iTable);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, (char*)pExpr->token.z, pExpr->token.n, 0);
................................................................................
    }
    case TK_FLOAT: {
      codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0);
      break;
    }
    case TK_STRING: {
      sqlite3DequoteExpr(pParse->db, pExpr);
      sqlite3VdbeAddOp4(v,OP_String8, 0, 0, 0,
                        (char*)pExpr->token.z, pExpr->token.n);
      break;
    }
    case TK_NULL: {
      sqlite3VdbeAddOp0(v, OP_Null);
      break;
    }
#ifndef SQLITE_OMIT_BLOB_LITERAL
    case TK_BLOB: {
      int n;
      const char *z;
      assert( TK_BLOB==OP_HexBlob );
      n = pExpr->token.n - 3;
      z = (char*)pExpr->token.z + 2;
      assert( n>=0 );
      if( n==0 ){
        z = "";
      }
      sqlite3VdbeAddOp4(v, op, 0, 0, 0, z, n);
      break;
    }
#endif
    case TK_VARIABLE: {
      sqlite3VdbeAddOp1(v, OP_Variable, pExpr->iTable);
      if( pExpr->token.n>1 ){
        sqlite3VdbeChangeP4(v, -1, (char*)pExpr->token.z, pExpr->token.n);
      }
      break;
    }
    case TK_REGISTER: {
      sqlite3VdbeAddOp1(v, OP_MemLoad, pExpr->iTable);
      break;
    }
#ifndef SQLITE_OMIT_CAST
    case TK_CAST: {
      /* Expressions of the form:   CAST(pLeft AS token) */
      int aff, to_op;
      sqlite3ExprCode(pParse, pExpr->pLeft);
................................................................................
      aff = sqlite3AffinityType(&pExpr->token);
      to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
      assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
      assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
      assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
      assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
      assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
      sqlite3VdbeAddOp0(v, to_op);
      stackChng = 0;
      break;
    }
#endif /* SQLITE_OMIT_CAST */
    case TK_LT:
    case TK_LE:
    case TK_GT:
................................................................................
      assert( TK_BITOR==OP_BitOr );
      assert( TK_SLASH==OP_Divide );
      assert( TK_LSHIFT==OP_ShiftLeft );
      assert( TK_RSHIFT==OP_ShiftRight );
      assert( TK_CONCAT==OP_Concat );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3ExprCode(pParse, pExpr->pRight);
      sqlite3VdbeAddOp0(v, op);
      stackChng = -1;
      break;
    }
    case TK_UMINUS: {
      Expr *pLeft = pExpr->pLeft;
      assert( pLeft );
      if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
................................................................................
      /* Fall through into TK_NOT */
    }
    case TK_BITNOT:
    case TK_NOT: {
      assert( TK_BITNOT==OP_BitNot );
      assert( TK_NOT==OP_Not );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp0(v, op);
      stackChng = 0;
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      int dest;
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3VdbeAddOp1(v, OP_Integer, 1);
      sqlite3ExprCode(pParse, pExpr->pLeft);
      dest = sqlite3VdbeCurrentAddr(v) + 2;
      sqlite3VdbeAddOp2(v, op, 1, dest);
      sqlite3VdbeAddOp1(v, OP_AddImm, -1);
      stackChng = 0;
      break;
    }
    case TK_AGG_FUNCTION: {
      AggInfo *pInfo = pExpr->pAggInfo;
      if( pInfo==0 ){
        sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
            &pExpr->span);
      }else{
        sqlite3VdbeAddOp1(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem);
      }
      break;
    }
    case TK_CONST_FUNC:
    case TK_FUNCTION: {
      ExprList *pList = pExpr->pList;
      int nExpr = pList ? pList->nExpr : 0;
................................................................................
        }
        if( pDef->needCollSeq && !pColl ){
          pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
        }
      }
      if( pDef->needCollSeq ){
        if( !pColl ) pColl = pParse->db->pDfltColl; 
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
      }
      sqlite3VdbeAddOp4(v, OP_Function, constMask, nExpr, 0,
                        (char*)pDef, P4_FUNCDEF);
      stackChng = 1-nExpr;
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      if( pExpr->iColumn==0 ){
        sqlite3CodeSubselect(pParse, pExpr);
      }
      sqlite3VdbeAddOp1(v, OP_MemLoad, pExpr->iColumn);
      VdbeComment((v, "load subquery result"));
      break;
    }
    case TK_IN: {
      int addr;
      char affinity;
      int ckOffset = pParse->ckOffset;
................................................................................
      int eType;
      int iLabel = sqlite3VdbeMakeLabel(v);

      eType = sqlite3FindInIndex(pParse, pExpr, 0);

      /* Figure out the affinity to use to create a key from the results
      ** of the expression. affinityStr stores a static string suitable for
      ** P4 of OP_MakeRecord.
      */
      affinity = comparisonAffinity(pExpr);

      sqlite3VdbeAddOp1(v, OP_Integer, 1);
      pParse->ckOffset = (ckOffset ? (ckOffset+1) : 0);

      /* Code the <expr> from "<expr> IN (...)". The temporary table
      ** pExpr->iTable contains the values that make up the (...) set.
      */
      sqlite3ExprCode(pParse, pExpr->pLeft);
      addr = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_NotNull, -1, addr+4);            /* addr + 0 */
      sqlite3VdbeAddOp1(v, OP_Pop, 2);
      sqlite3VdbeAddOp0(v, OP_Null);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iLabel);
      if( eType==IN_INDEX_ROWID ){
        int iAddr = sqlite3VdbeCurrentAddr(v)+3;
        sqlite3VdbeAddOp2(v, OP_MustBeInt, 1, iAddr);
        sqlite3VdbeAddOp2(v, OP_NotExists, pExpr->iTable, iAddr);
        sqlite3VdbeAddOp2(v, OP_Goto, pExpr->iTable, iLabel);
      }else{
        sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0,
                             &affinity, 1);   /* addr + 4 */
        sqlite3VdbeAddOp2(v, OP_Found, pExpr->iTable, iLabel);
      }

      sqlite3VdbeAddOp1(v, OP_AddImm, -1);                     /* addr + 6 */
      sqlite3VdbeResolveLabel(v, iLabel);

      break;
    }
#endif
    case TK_BETWEEN: {
      Expr *pLeft = pExpr->pLeft;
      struct ExprList_item *pLItem = pExpr->pList->a;
      Expr *pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp0(v, OP_Dup);
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
      sqlite3VdbeAddOp1(v, OP_Pull, 1);
      pLItem++;
      pRight = pLItem->pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
      sqlite3VdbeAddOp0(v, OP_And);
      break;
    }
    case TK_UPLUS: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      stackChng = 0;
      break;
    }
................................................................................
      expr_end_label = sqlite3VdbeMakeLabel(v);
      if( pExpr->pLeft ){
        sqlite3ExprCode(pParse, pExpr->pLeft);
      }
      for(i=0; i<nExpr; i=i+2){
        sqlite3ExprCode(pParse, aListelem[i].pExpr);
        if( pExpr->pLeft ){
          sqlite3VdbeAddOp2(v, OP_Dup, 1, 1);
          jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
                                 OP_Ne, 0, 1);
          sqlite3VdbeAddOp1(v, OP_Pop, 1);
        }else{
          jumpInst = sqlite3VdbeAddOp2(v, OP_IfNot, 1, 0);
        }
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, expr_end_label);
        sqlite3VdbeJumpHere(v, jumpInst);
      }
      if( pExpr->pLeft ){
        sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
      }
      if( pExpr->pRight ){
        sqlite3ExprCode(pParse, pExpr->pRight);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
      }
      sqlite3VdbeResolveLabel(v, expr_end_label);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      if( !pParse->trigStack ){
................................................................................
        return;
      }
      if( pExpr->iColumn!=OE_Ignore ){
         assert( pExpr->iColumn==OE_Rollback ||
                 pExpr->iColumn == OE_Abort ||
                 pExpr->iColumn == OE_Fail );
         sqlite3DequoteExpr(pParse->db, pExpr);
         sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn, 0,
                        (char*)pExpr->token.z, pExpr->token.n);
      } else {
         assert( pExpr->iColumn == OE_Ignore );
         sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
         sqlite3VdbeAddOp2(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
         VdbeComment((v, "raise(IGNORE)"));
      }
      stackChng = 0;
      break;
    }
#endif
  }
................................................................................
  if( v==0 ) return;
  addr1 = sqlite3VdbeCurrentAddr(v);
  sqlite3ExprCode(pParse, pExpr);
  addr2 = sqlite3VdbeCurrentAddr(v);
  if( addr2>addr1+1
   || ((pOp = sqlite3VdbeGetOp(v, addr1))!=0 && pOp->opcode==OP_Function) ){
    iMem = pExpr->iTable = pParse->nMem++;
    sqlite3VdbeAddOp2(v, OP_MemStore, iMem, 0);
    pExpr->op = TK_REGISTER;
  }
}
#endif

/*
** Generate code to evaluate an expression and store the result in
................................................................................
int sqlite3ExprIntoReg(Parse *pParse, Expr *pExpr, int target){
  Vdbe *v = pParse->pVdbe;
  if( v==0 ) return -1;
  sqlite3ExprCode(pParse, pExpr);
  if( target<0 ){
    target = pParse->nMem++;
  }
  sqlite3VdbeAddOp2(v, OP_MemStore, target, 1);
  return target;
}

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack.
**
................................................................................
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      assert( TK_ISNULL==OP_IsNull );
      assert( TK_NOTNULL==OP_NotNull );
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp2(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression "x BETWEEN y AND z" is implemented as:
      **
      ** 1 IF (x < y) GOTO 3
      ** 2 IF (x <= z) GOTO <dest>
      ** 3 ...
      */
      int addr;
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pList->a[0].pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp2(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);

      pRight = pExpr->pList->a[1].pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);

      sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
      sqlite3VdbeJumpHere(v, addr);
      sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp2(v, OP_If, jumpIfNull, dest);
      break;
    }
  }
  pParse->ckOffset = ckOffset;
}

/*
................................................................................
      sqlite3ExprCode(pParse, pExpr->pRight);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      sqlite3VdbeAddOp2(v, op, 1, dest);
      break;
    }
    case TK_BETWEEN: {
      /* The expression is "x BETWEEN y AND z". It is implemented as:
      **
      ** 1 IF (x >= y) GOTO 3
      ** 2 GOTO <dest>
      ** 3 IF (x > z) GOTO <dest>
      */
      int addr;
      Expr *pLeft = pExpr->pLeft;
      Expr *pRight = pExpr->pList->a[0].pExpr;
      sqlite3ExprCode(pParse, pLeft);
      sqlite3VdbeAddOp2(v, OP_Dup, 0, 0);
      sqlite3ExprCode(pParse, pRight);
      addr = sqlite3VdbeCurrentAddr(v);
      codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull);

      sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, dest);
      pRight = pExpr->pList->a[1].pExpr;
      sqlite3ExprCode(pParse, pRight);
      codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp2(v, OP_IfNot, jumpIfNull, dest);
      break;
    }
  }
  pParse->ckOffset = ckOffset;
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.201 2008/01/02 16:27:10 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
**
**  Character      Column affinity
**  ------------------------------
**  'a'            TEXT
**  'b'            NONE
................................................................................
    }
    for(n=0; n<pIdx->nColumn; n++){
      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
    }
    pIdx->zColAff[pIdx->nColumn] = '\0';
  }
 
  sqlite3VdbeChangeP3(v, -1, pIdx->zColAff, 0);
}

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for table pTab. A column affinity string has one character
** for each column indexed by the index, according to the affinity of the
** column:
**
**  Character      Column affinity
**  ------------------------------
**  'a'            TEXT
................................................................................
      zColAff[i] = pTab->aCol[i].affinity;
    }
    zColAff[pTab->nCol] = '\0';

    pTab->zColAff = zColAff;
  }

  sqlite3VdbeChangeP3(v, -1, pTab->zColAff, 0);
}

/*
** Return non-zero if the table pTab in database iDb or any of its indices
** have been opened at any point in the VDBE program beginning at location
** iStartAddr throught the end of the program.  This is used to see if 
** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can 
................................................................................
          if( tnum==pIndex->tnum ){
            return 1;
          }
        }
      }
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pOp->opcode==OP_VOpen && pOp->p3.p==(const char*)pTab->pVtab ){
      assert( pOp->p3.p!=0 );
      assert( pOp->p3type==P3_VTAB );
      return 1;
    }
#endif
  }
  return 0;
}

................................................................................
    int iCur = pParse->nTab;
    int addr;
    assert( v );
    addr = sqlite3VdbeCurrentAddr(v);
    memId = pParse->nMem+1;
    pParse->nMem += 2;
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    sqlite3VdbeAddOp(v, OP_Rewind, iCur, addr+13);
    sqlite3VdbeAddOp(v, OP_Column, iCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp(v, OP_Ne, 0x100, addr+12);
    sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, memId-1, 1);
    sqlite3VdbeAddOp(v, OP_Column, iCur, 1);
    sqlite3VdbeAddOp(v, OP_MemStore, memId, 1);
    sqlite3VdbeAddOp(v, OP_Goto, 0, addr+13);
    sqlite3VdbeAddOp(v, OP_Next, iCur, addr+4);
    sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
  }
  return memId;
}

/*
** Update the maximum rowid for an autoincrement calculation.
**
................................................................................
** This routine should be called when the top of the stack holds a
** new rowid that is about to be inserted.  If that new rowid is
** larger than the maximum rowid in the memId memory cell, then the
** memory cell is updated.  The stack is unchanged.
*/
static void autoIncStep(Parse *pParse, int memId){
  if( memId>0 ){
    sqlite3VdbeAddOp(pParse->pVdbe, OP_MemMax, memId, 0);
  }
}

/*
** After doing one or more inserts, the maximum rowid is stored
** in mem[memId].  Generate code to write this value back into the
** the sqlite_sequence table.
................................................................................
    int iCur = pParse->nTab;
    Vdbe *v = pParse->pVdbe;
    Db *pDb = &pParse->db->aDb[iDb];
    int addr;
    assert( v );
    addr = sqlite3VdbeCurrentAddr(v);
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    sqlite3VdbeAddOp(v, OP_MemLoad, memId-1, 0);
    sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+7);
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_NewRowid, iCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp(v, OP_MemLoad, memId, 0);
    sqlite3VdbeAddOp(v, OP_MakeRecord, 2, 0);
    sqlite3VdbeAddOp(v, OP_Insert, iCur, OPFLAG_APPEND);
    sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
  }
}
#else
/*
** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
** above are all no-ops
*/
................................................................................
  ** results in a temporary table. (Template 3.)
  */
  if( pSelect ){
    /* Data is coming from a SELECT.  Generate code to implement that SELECT
    */
    SelectDest dest = {SRT_Subroutine, 0, 0};
    int rc, iInitCode;
    iInitCode = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iSelectLoop = sqlite3VdbeCurrentAddr(v);
    iInsertBlock = sqlite3VdbeMakeLabel(v);
    dest.iParm = iInsertBlock;

    /* Resolve the expressions in the SELECT statement and execute it. */
    rc = sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
    if( rc || pParse->nErr || db->mallocFailed ){
      goto insert_cleanup;
    }

    iCleanup = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
    ** should be written into a temporary table.  Set to FALSE if each
    ** row of the SELECT can be written directly into the result table.
    **
................................................................................

    if( useTempTable ){
      /* Generate the subroutine that SELECT calls to process each row of
      ** the result.  Store the result in a temporary table
      */
      srcTab = pParse->nTab++;
      sqlite3VdbeResolveLabel(v, iInsertBlock);
      sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
      sqlite3VdbeAddOp(v, OP_NewRowid, srcTab, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_Insert, srcTab, OPFLAG_APPEND);
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeJumpHere(v, iInitCode);
      sqlite3VdbeAddOp(v, OP_OpenEphemeral, srcTab, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, srcTab, nColumn);
      sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
      sqlite3VdbeResolveLabel(v, iCleanup);
    }else{
      sqlite3VdbeJumpHere(v, iInitCode);
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
    ** clause
................................................................................
  if( pColumn==0 && nColumn>0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( triggers_exist ){
    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemInt, 0, iCntMem);
  }

  /* If this is not a view, open the table and and all indices */
  if( !isView ){
    base = pParse->nTab;
    sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
  }
................................................................................
  /* If the data source is a temporary table, then we have to create
  ** a loop because there might be multiple rows of data.  If the data
  ** source is a subroutine call from the SELECT statement, then we need
  ** to launch the SELECT statement processing.
  */
  if( useTempTable ){
    iBreak = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Rewind, srcTab, iBreak);
    iCont = sqlite3VdbeCurrentAddr(v);
  }else if( pSelect ){
    sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
    sqlite3VdbeResolveLabel(v, iInsertBlock);
    sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
  }

  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqlite3VdbeMakeLabel(v);
  if( triggers_exist & TRIGGER_BEFORE ){

................................................................................
    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,
    ** we do not know what the unique ID will be (because the insert has
    ** not happened yet) so we substitute a rowid of -1
    */
    if( keyColumn<0 ){
      sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
    }else if( useTempTable ){
      sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
    }else{
      assert( pSelect==0 );  /* Otherwise useTempTable is true */
      sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
      sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp(v, OP_Integer, -1, 0);
      sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
    }

    /* Cannot have triggers on a virtual table. If it were possible,
    ** this block would have to account for hidden column.
    */
    assert(!IsVirtual(pTab));

................................................................................
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
      }else if( useTempTable ){
        sqlite3VdbeAddOp(v, OP_Column, srcTab, j); 
      }else{
        assert( pSelect==0 ); /* Otherwise useTempTable is true */
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
      }
    }
    sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);

    /* Fire BEFORE or INSTEAD OF triggers */
    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab, 
        newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
    }
  }
................................................................................
  ** record number is a randomly generate integer created by NewRowid
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */
  if( !isView ){
    if( IsVirtual(pTab) ){
      /* The row that the VUpdate opcode will delete:  none */
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    }
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqlite3VdbeAddOp(v, OP_Column, srcTab, keyColumn);
      }else if( pSelect ){
        sqlite3VdbeAddOp(v, OP_Dup, nColumn - keyColumn - 1, 1);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
        if( pOp && pOp->opcode==OP_Null ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
................................................................................
          pOp->p2 = counterMem;
        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
        sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
        sqlite3VdbeAddOp(v, OP_NewRowid, base, counterMem);
        sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
      }
    }else if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    }else{
      sqlite3VdbeAddOp(v, OP_NewRowid, base, counterMem);
      appendFlag = 1;
    }
    autoIncStep(pParse, counterMem);

    /* Push onto the stack, data for all columns of the new entry, beginning
    ** with the first column.
    */
................................................................................
    nHidden = 0;
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
        ** Whenever this column is read, the record number will be substituted
        ** in its place.  So will fill this column with a NULL to avoid
        ** taking up data space with information that will never be used. */
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
        continue;
      }
      if( pColumn==0 ){
        if( IsHiddenColumn(&pTab->aCol[i]) ){
          assert( IsVirtual(pTab) );
          j = -1;
          nHidden++;
................................................................................
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
      }else if( useTempTable ){
        sqlite3VdbeAddOp(v, OP_Column, srcTab, j); 
      }else if( pSelect ){
        sqlite3VdbeAddOp(v, OP_Dup, i+nColumn-j+IsVirtual(pTab), 1);
      }else{
        sqlite3ExprCode(pParse, pList->a[j].pExpr);
      }
    }

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.
    */
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      pParse->pVirtualLock = pTab;
      sqlite3VdbeOp3(v, OP_VUpdate, 1, pTab->nCol+2,
                     (const char*)pTab->pVtab, P3_VTAB);
    }else
#endif
    {
      sqlite3GenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
                                     0, onError, endOfLoop);
      sqlite3CompleteInsertion(pParse, pTab, base, 0,0,0,
                            (triggers_exist & TRIGGER_AFTER)!=0 ? newIdx : -1,
................................................................................
                            appendFlag);
    }
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqlite3VdbeAddOp(v, OP_MemIncr, 1, iCntMem);
  }

  if( triggers_exist ){
    /* Code AFTER triggers */
    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
          newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
................................................................................
    }
  }

  /* The bottom of the loop, if the data source is a SELECT statement
  */
  sqlite3VdbeResolveLabel(v, endOfLoop);
  if( useTempTable ){
    sqlite3VdbeAddOp(v, OP_Next, srcTab, iCont);
    sqlite3VdbeResolveLabel(v, iBreak);
    sqlite3VdbeAddOp(v, OP_Close, srcTab, 0);
  }else if( pSelect ){
    sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
    sqlite3VdbeAddOp(v, OP_Return, 0, 0);
    sqlite3VdbeResolveLabel(v, iCleanup);
  }

  if( !IsVirtual(pTab) && !isView ){
    /* Close all tables opened */
    sqlite3VdbeAddOp(v, OP_Close, base, 0);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqlite3VdbeAddOp(v, OP_Close, idx+base, 0);
    }
  }

  /* Update the sqlite_sequence table by storing the content of the
  ** counter value in memory counterMem back into the sqlite_sequence
  ** table.
  */
................................................................................

  /*
  ** Return the number of rows inserted. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
    sqlite3VdbeAddOp(v, OP_ResultRow, iCntMem, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", P3_STATIC);
  }

insert_cleanup:
  sqlite3SrcListDelete(pTabList);
  sqlite3ExprListDelete(pList);
  sqlite3SelectDelete(pSelect);
  sqlite3IdListDelete(pColumn);
................................................................................
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
      onError = OE_Abort;
    }
    sqlite3VdbeAddOp(v, OP_Dup, nCol-1-i, 1);
    addr = sqlite3VdbeAddOp(v, OP_NotNull, 1, 0);
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        char *zMsg = 0;
        sqlite3VdbeAddOp(v, OP_Halt, SQLITE_CONSTRAINT, onError);
        sqlite3SetString(&zMsg, pTab->zName, ".", pTab->aCol[i].zName,
                        " may not be NULL", (char*)0);
        sqlite3VdbeChangeP3(v, -1, zMsg, P3_DYNAMIC);
        break;
      }
      case OE_Ignore: {
        sqlite3VdbeAddOp(v, OP_Pop, nCol+1+hasTwoRowids, 0);
        sqlite3VdbeAddOp(v, OP_Goto, 0, ignoreDest);
        break;
      }
      case OE_Replace: {
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
        sqlite3VdbeAddOp(v, OP_Push, nCol-i, 0);
        break;
      }
    }
    sqlite3VdbeJumpHere(v, addr);
  }

  /* Test all CHECK constraints
................................................................................
    assert( pParse->ckOffset==0 );
    pParse->ckOffset = nCol;
    sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, 1);
    assert( pParse->ckOffset==nCol );
    pParse->ckOffset = 0;
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    if( onError==OE_Ignore ){
      sqlite3VdbeAddOp(v, OP_Pop, nCol+1+hasTwoRowids, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, ignoreDest);
    }else{
      sqlite3VdbeAddOp(v, OP_Halt, SQLITE_CONSTRAINT, onError);
    }
    sqlite3VdbeResolveLabel(v, allOk);
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
  ** of the new record does not previously exist.  Except, if this
................................................................................
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    
    if( isUpdate ){
      sqlite3VdbeAddOp(v, OP_Dup, nCol+1, 1);
      sqlite3VdbeAddOp(v, OP_Dup, nCol+1, 1);
      jumpInst1 = sqlite3VdbeAddOp(v, OP_Eq, 0, 0);
    }
    sqlite3VdbeAddOp(v, OP_Dup, nCol, 1);
    jumpInst2 = sqlite3VdbeAddOp(v, OP_NotExists, base, 0);
    switch( onError ){
      default: {
        onError = OE_Abort;
        /* Fall thru into the next case */
      }
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError,
                         "PRIMARY KEY must be unique", P3_STATIC);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowIndexDelete(v, pTab, base, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp(v, OP_Dup, nCol+hasTwoRowids, 1);
          sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp(v, OP_Pop, nCol+1+hasTwoRowids, 0);
        sqlite3VdbeAddOp(v, OP_Goto, 0, ignoreDest);
        break;
      }
    }
    sqlite3VdbeJumpHere(v, jumpInst2);
    if( isUpdate ){
      sqlite3VdbeJumpHere(v, jumpInst1);
      sqlite3VdbeAddOp(v, OP_Dup, nCol+1, 1);
      sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
    }
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */
  extra = -1;
  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
    if( aIdxUsed && aIdxUsed[iCur]==0 ) continue;  /* Skip unused indices */
    extra++;

    /* Create a key for accessing the index entry */
    sqlite3VdbeAddOp(v, OP_Dup, nCol+extra, 1);
    for(i=0; i<pIdx->nColumn; i++){
      int idx = pIdx->aiColumn[i];
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp(v, OP_Dup, i+extra+nCol+1, 1);
      }else{
        sqlite3VdbeAddOp(v, OP_Dup, i+extra+nCol-idx, 1);
      }
    }
    jumpInst1 = sqlite3VdbeAddOp(v, OP_MakeIdxRec, pIdx->nColumn, 0);
    sqlite3IndexAffinityStr(v, pIdx);

    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
    if( overrideError!=OE_Default ){
      onError = overrideError;
................................................................................
    if( seenReplace ){
      if( onError==OE_Ignore ) onError = OE_Replace;
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    

    /* Check to see if the new index entry will be unique */
    sqlite3VdbeAddOp(v, OP_Dup, extra+nCol+1+hasTwoRowids, 1);
    jumpInst2 = sqlite3VdbeAddOp(v, OP_IsUnique, base+iCur+1, 0);

    /* Generate code that executes if the new index entry is not unique */
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:
................................................................................
          }else{
            sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], "%s", zCol);
            n1 += n2;
          }
        }
        sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], 
            pIdx->nColumn>1 ? " are not unique" : " is not unique");
        sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError, zErrMsg, 0);
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp(v, OP_Pop, nCol+extra+3+hasTwoRowids, 0);
        sqlite3VdbeAddOp(v, OP_Goto, 0, ignoreDest);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowDelete(pParse->db, v, pTab, base, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRowids, 1);
          sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
        }
        seenReplace = 1;
        break;
      }
    }
#if NULL_DISTINCT_FOR_UNIQUE
    sqlite3VdbeJumpHere(v, jumpInst1);
................................................................................

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aIdxUsed && aIdxUsed[i]==0 ) continue;
    sqlite3VdbeAddOp(v, OP_IdxInsert, base+i+1, 0);
  }
  sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
  sqlite3TableAffinityStr(v, pTab);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){
    sqlite3VdbeAddOp(v, OP_Dup, 1, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 1, 0);
    sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);
  }
#endif
  if( pParse->nested ){
    pik_flags = 0;
  }else{
    pik_flags = OPFLAG_NCHANGE;
    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
  }
  if( appendBias ){
    pik_flags |= OPFLAG_APPEND;
  }
  sqlite3VdbeAddOp(v, OP_Insert, base, pik_flags);
  if( !pParse->nested ){
    sqlite3VdbeChangeP3(v, -1, pTab->zName, P3_STATIC);
  }
  
  if( isUpdate && rowidChng ){
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
  }
}

/*
** Generate code that will open cursors for a table and for all
** indices of that table.  The "base" parameter is the cursor number used
** for the table.  Indices are opened on subsequent cursors.
................................................................................
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  sqlite3OpenTable(pParse, base, iDb, pTab, op);
  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
    VdbeComment((v, "%s", pIdx->zName));
    sqlite3VdbeOp3(v, op, i+base, pIdx->tnum, (char*)pKey, P3_KEYINFO_HANDOFF);

  }
  if( pParse->nTab<=base+i ){
    pParse->nTab = base+i;
  }
}


................................................................................
    ** the rowids might change which will mess up indexing.
    **
    ** Or if the destination has a UNIQUE index and is not empty,
    ** we also disallow the transfer optimization because we cannot
    ** insure that all entries in the union of DEST and SRC will be
    ** unique.
    */
    addr1 = sqlite3VdbeAddOp(v, OP_Rewind, iDest, 0);
    emptyDestTest = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
  }else{
    emptyDestTest = 0;
  }
  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
  emptySrcTest = sqlite3VdbeAddOp(v, OP_Rewind, iSrc, 0);
  if( pDest->iPKey>=0 ){
    addr1 = sqlite3VdbeAddOp(v, OP_Rowid, iSrc, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    addr2 = sqlite3VdbeAddOp(v, OP_NotExists, iDest, 0);
    sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, onError, 
                      "PRIMARY KEY must be unique", P3_STATIC);
    sqlite3VdbeJumpHere(v, addr2);
    autoIncStep(pParse, counterMem);
  }else if( pDest->pIndex==0 ){
    addr1 = sqlite3VdbeAddOp(v, OP_NewRowid, iDest, 0);
  }else{
    addr1 = sqlite3VdbeAddOp(v, OP_Rowid, iSrc, 0);
    assert( pDest->autoInc==0 );
  }
  sqlite3VdbeAddOp(v, OP_RowData, iSrc, 0);
  sqlite3VdbeOp3(v, OP_Insert, iDest,
                    OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND,
                    pDest->zName, 0);
  sqlite3VdbeAddOp(v, OP_Next, iSrc, addr1);
  autoIncEnd(pParse, iDbDest, pDest, counterMem);
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    assert( pSrcIdx );
    sqlite3VdbeAddOp(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp(v, OP_Close, iDest, 0);
    sqlite3VdbeAddOp(v, OP_Integer, iDbSrc, 0);
    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
    VdbeComment((v, "%s", pSrcIdx->zName));
    sqlite3VdbeOp3(v, OP_OpenRead, iSrc, pSrcIdx->tnum, 
                   (char*)pKey, P3_KEYINFO_HANDOFF);
    sqlite3VdbeAddOp(v, OP_Integer, iDbDest, 0);
    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
    VdbeComment((v, "%s", pDestIdx->zName));
    sqlite3VdbeOp3(v, OP_OpenWrite, iDest, pDestIdx->tnum, 
                   (char*)pKey, P3_KEYINFO_HANDOFF);
    addr1 = sqlite3VdbeAddOp(v, OP_Rewind, iSrc, 0);
    sqlite3VdbeAddOp(v, OP_RowKey, iSrc, 0);
    sqlite3VdbeAddOp(v, OP_IdxInsert, iDest, 1);
    sqlite3VdbeAddOp(v, OP_Next, iSrc, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
  }
  sqlite3VdbeJumpHere(v, emptySrcTest);
  sqlite3VdbeAddOp(v, OP_Close, iSrc, 0);
  sqlite3VdbeAddOp(v, OP_Close, iDest, 0);
  if( emptyDestTest ){
    sqlite3VdbeAddOp(v, OP_Halt, SQLITE_OK, 0);
    sqlite3VdbeJumpHere(v, emptyDestTest);
    sqlite3VdbeAddOp(v, OP_Close, iDest, 0);
    return 0;
  }else{
    return 1;
  }
}
#endif /* SQLITE_OMIT_XFER_OPT */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.202 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:
**
**  Character      Column affinity
**  ------------------------------
**  'a'            TEXT
**  'b'            NONE
................................................................................
    }
    for(n=0; n<pIdx->nColumn; n++){
      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
    }
    pIdx->zColAff[pIdx->nColumn] = '\0';
  }
 
  sqlite3VdbeChangeP4(v, -1, pIdx->zColAff, 0);
}

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for table pTab. A column affinity string has one character
** for each column indexed by the index, according to the affinity of the
** column:
**
**  Character      Column affinity
**  ------------------------------
**  'a'            TEXT
................................................................................
      zColAff[i] = pTab->aCol[i].affinity;
    }
    zColAff[pTab->nCol] = '\0';

    pTab->zColAff = zColAff;
  }

  sqlite3VdbeChangeP4(v, -1, pTab->zColAff, 0);
}

/*
** Return non-zero if the table pTab in database iDb or any of its indices
** have been opened at any point in the VDBE program beginning at location
** iStartAddr throught the end of the program.  This is used to see if 
** a statement of the form  "INSERT INTO <iDb, pTab> SELECT ..." can 
................................................................................
          if( tnum==pIndex->tnum ){
            return 1;
          }
        }
      }
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pOp->opcode==OP_VOpen && pOp->p4.p==(const char*)pTab->pVtab ){
      assert( pOp->p4.p!=0 );
      assert( pOp->p4type==P4_VTAB );
      return 1;
    }
#endif
  }
  return 0;
}

................................................................................
    int iCur = pParse->nTab;
    int addr;
    assert( v );
    addr = sqlite3VdbeCurrentAddr(v);
    memId = pParse->nMem+1;
    pParse->nMem += 2;
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);
    sqlite3VdbeAddOp2(v, OP_Rewind, iCur, addr+13);
    sqlite3VdbeAddOp2(v, OP_Column, iCur, 0);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp2(v, OP_Ne, 0x100, addr+12);
    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
    sqlite3VdbeAddOp2(v, OP_MemStore, memId-1, 1);
    sqlite3VdbeAddOp2(v, OP_Column, iCur, 1);
    sqlite3VdbeAddOp2(v, OP_MemStore, memId, 1);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addr+13);
    sqlite3VdbeAddOp2(v, OP_Next, iCur, addr+4);
    sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  }
  return memId;
}

/*
** Update the maximum rowid for an autoincrement calculation.
**
................................................................................
** This routine should be called when the top of the stack holds a
** new rowid that is about to be inserted.  If that new rowid is
** larger than the maximum rowid in the memId memory cell, then the
** memory cell is updated.  The stack is unchanged.
*/
static void autoIncStep(Parse *pParse, int memId){
  if( memId>0 ){
    sqlite3VdbeAddOp2(pParse->pVdbe, OP_MemMax, memId, 0);
  }
}

/*
** After doing one or more inserts, the maximum rowid is stored
** in mem[memId].  Generate code to write this value back into the
** the sqlite_sequence table.
................................................................................
    int iCur = pParse->nTab;
    Vdbe *v = pParse->pVdbe;
    Db *pDb = &pParse->db->aDb[iDb];
    int addr;
    assert( v );
    addr = sqlite3VdbeCurrentAddr(v);
    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);
    sqlite3VdbeAddOp2(v, OP_MemLoad, memId-1, 0);
    sqlite3VdbeAddOp2(v, OP_NotNull, -1, addr+7);
    sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp2(v, OP_NewRowid, iCur, 0);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp2(v, OP_MemLoad, memId, 0);
    sqlite3VdbeAddOp2(v, OP_MakeRecord, 2, 0);
    sqlite3VdbeAddOp2(v, OP_Insert, iCur, OPFLAG_APPEND);
    sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  }
}
#else
/*
** If SQLITE_OMIT_AUTOINCREMENT is defined, then the three routines
** above are all no-ops
*/
................................................................................
  ** results in a temporary table. (Template 3.)
  */
  if( pSelect ){
    /* Data is coming from a SELECT.  Generate code to implement that SELECT
    */
    SelectDest dest = {SRT_Subroutine, 0, 0};
    int rc, iInitCode;
    iInitCode = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    iSelectLoop = sqlite3VdbeCurrentAddr(v);
    iInsertBlock = sqlite3VdbeMakeLabel(v);
    dest.iParm = iInsertBlock;

    /* Resolve the expressions in the SELECT statement and execute it. */
    rc = sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);
    if( rc || pParse->nErr || db->mallocFailed ){
      goto insert_cleanup;
    }

    iCleanup = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iCleanup);
    assert( pSelect->pEList );
    nColumn = pSelect->pEList->nExpr;

    /* Set useTempTable to TRUE if the result of the SELECT statement
    ** should be written into a temporary table.  Set to FALSE if each
    ** row of the SELECT can be written directly into the result table.
    **
................................................................................

    if( useTempTable ){
      /* Generate the subroutine that SELECT calls to process each row of
      ** the result.  Store the result in a temporary table
      */
      srcTab = pParse->nTab++;
      sqlite3VdbeResolveLabel(v, iInsertBlock);
      sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);
      sqlite3VdbeAddOp2(v, OP_MakeRecord, nColumn, 0);
      sqlite3VdbeAddOp2(v, OP_NewRowid, srcTab, 0);
      sqlite3VdbeAddOp2(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Insert, srcTab, OPFLAG_APPEND);
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeJumpHere(v, iInitCode);
      sqlite3VdbeAddOp2(v, OP_OpenEphemeral, srcTab, 0);
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, srcTab, nColumn);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
      sqlite3VdbeResolveLabel(v, iCleanup);
    }else{
      sqlite3VdbeJumpHere(v, iInitCode);
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
    ** clause
................................................................................
  if( pColumn==0 && nColumn>0 ){
    keyColumn = pTab->iPKey;
  }

  /* Open the temp table for FOR EACH ROW triggers
  */
  if( triggers_exist ){
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, newIdx, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqlite3VdbeAddOp2(v, OP_MemInt, 0, iCntMem);
  }

  /* If this is not a view, open the table and and all indices */
  if( !isView ){
    base = pParse->nTab;
    sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
  }
................................................................................
  /* If the data source is a temporary table, then we have to create
  ** a loop because there might be multiple rows of data.  If the data
  ** source is a subroutine call from the SELECT statement, then we need
  ** to launch the SELECT statement processing.
  */
  if( useTempTable ){
    iBreak = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp2(v, OP_Rewind, srcTab, iBreak);
    iCont = sqlite3VdbeCurrentAddr(v);
  }else if( pSelect ){
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iSelectLoop);
    sqlite3VdbeResolveLabel(v, iInsertBlock);
    sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);
  }

  /* Run the BEFORE and INSTEAD OF triggers, if there are any
  */
  endOfLoop = sqlite3VdbeMakeLabel(v);
  if( triggers_exist & TRIGGER_BEFORE ){

................................................................................
    /* build the NEW.* reference row.  Note that if there is an INTEGER
    ** PRIMARY KEY into which a NULL is being inserted, that NULL will be
    ** translated into a unique ID for the row.  But on a BEFORE trigger,
    ** we do not know what the unique ID will be (because the insert has
    ** not happened yet) so we substitute a rowid of -1
    */
    if( keyColumn<0 ){
      sqlite3VdbeAddOp2(v, OP_Integer, -1, 0);
    }else if( useTempTable ){
      sqlite3VdbeAddOp2(v, OP_Column, srcTab, keyColumn);
    }else{
      assert( pSelect==0 );  /* Otherwise useTempTable is true */
      sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
      sqlite3VdbeAddOp2(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Integer, -1, 0);
      sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    }

    /* Cannot have triggers on a virtual table. If it were possible,
    ** this block would have to account for hidden column.
    */
    assert(!IsVirtual(pTab));

................................................................................
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( pColumn && j>=pColumn->nId ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
      }else if( useTempTable ){
        sqlite3VdbeAddOp2(v, OP_Column, srcTab, j); 
      }else{
        assert( pSelect==0 ); /* Otherwise useTempTable is true */
        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr);
      }
    }
    sqlite3VdbeAddOp2(v, OP_MakeRecord, pTab->nCol, 0);

    /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
    ** do not attempt any conversions before assembling the record.
    ** If this is a real table, attempt conversions as required by the
    ** table column affinities.
    */
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    sqlite3VdbeAddOp2(v, OP_Insert, newIdx, 0);

    /* Fire BEFORE or INSTEAD OF triggers */
    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_BEFORE, pTab, 
        newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
    }
  }
................................................................................
  ** record number is a randomly generate integer created by NewRowid
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */
  if( !isView ){
    if( IsVirtual(pTab) ){
      /* The row that the VUpdate opcode will delete:  none */
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
    }
    if( keyColumn>=0 ){
      if( useTempTable ){
        sqlite3VdbeAddOp2(v, OP_Column, srcTab, keyColumn);
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_Dup, nColumn - keyColumn - 1, 1);
      }else{
        VdbeOp *pOp;
        sqlite3ExprCode(pParse, pList->a[keyColumn].pExpr);
        pOp = sqlite3VdbeGetOp(v, sqlite3VdbeCurrentAddr(v) - 1);
        if( pOp && pOp->opcode==OP_Null ){
          appendFlag = 1;
          pOp->opcode = OP_NewRowid;
................................................................................
          pOp->p2 = counterMem;
        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        sqlite3VdbeAddOp2(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
        sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
        sqlite3VdbeAddOp2(v, OP_NewRowid, base, counterMem);
        sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
      }
    }else if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
    }else{
      sqlite3VdbeAddOp2(v, OP_NewRowid, base, counterMem);
      appendFlag = 1;
    }
    autoIncStep(pParse, counterMem);

    /* Push onto the stack, data for all columns of the new entry, beginning
    ** with the first column.
    */
................................................................................
    nHidden = 0;
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
        ** Whenever this column is read, the record number will be substituted
        ** in its place.  So will fill this column with a NULL to avoid
        ** taking up data space with information that will never be used. */
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        continue;
      }
      if( pColumn==0 ){
        if( IsHiddenColumn(&pTab->aCol[i]) ){
          assert( IsVirtual(pTab) );
          j = -1;
          nHidden++;
................................................................................
        for(j=0; j<pColumn->nId; j++){
          if( pColumn->a[j].idx==i ) break;
        }
      }
      if( j<0 || nColumn==0 || (pColumn && j>=pColumn->nId) ){
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
      }else if( useTempTable ){
        sqlite3VdbeAddOp2(v, OP_Column, srcTab, j); 
      }else if( pSelect ){
        sqlite3VdbeAddOp2(v, OP_Dup, i+nColumn-j+IsVirtual(pTab), 1);
      }else{
        sqlite3ExprCode(pParse, pList->a[j].pExpr);
      }
    }

    /* Generate code to check constraints and generate index keys and
    ** do the insertion.
    */
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( IsVirtual(pTab) ){
      pParse->pVirtualLock = pTab;
      sqlite3VdbeAddOp4(v, OP_VUpdate, 1, pTab->nCol+2, 0,
                     (const char*)pTab->pVtab, P4_VTAB);
    }else
#endif
    {
      sqlite3GenerateConstraintChecks(pParse, pTab, base, 0, keyColumn>=0,
                                     0, onError, endOfLoop);
      sqlite3CompleteInsertion(pParse, pTab, base, 0,0,0,
                            (triggers_exist & TRIGGER_AFTER)!=0 ? newIdx : -1,
................................................................................
                            appendFlag);
    }
  }

  /* Update the count of rows that are inserted
  */
  if( (db->flags & SQLITE_CountRows)!=0 ){
    sqlite3VdbeAddOp2(v, OP_MemIncr, 1, iCntMem);
  }

  if( triggers_exist ){
    /* Code AFTER triggers */
    if( sqlite3CodeRowTrigger(pParse, TK_INSERT, 0, TRIGGER_AFTER, pTab,
          newIdx, -1, onError, endOfLoop, 0, 0) ){
      goto insert_cleanup;
................................................................................
    }
  }

  /* The bottom of the loop, if the data source is a SELECT statement
  */
  sqlite3VdbeResolveLabel(v, endOfLoop);
  if( useTempTable ){
    sqlite3VdbeAddOp2(v, OP_Next, srcTab, iCont);
    sqlite3VdbeResolveLabel(v, iBreak);
    sqlite3VdbeAddOp2(v, OP_Close, srcTab, 0);
  }else if( pSelect ){
    sqlite3VdbeAddOp2(v, OP_Pop, nColumn, 0);
    sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
    sqlite3VdbeResolveLabel(v, iCleanup);
  }

  if( !IsVirtual(pTab) && !isView ){
    /* Close all tables opened */
    sqlite3VdbeAddOp2(v, OP_Close, base, 0);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqlite3VdbeAddOp2(v, OP_Close, idx+base, 0);
    }
  }

  /* Update the sqlite_sequence table by storing the content of the
  ** counter value in memory counterMem back into the sqlite_sequence
  ** table.
  */
................................................................................

  /*
  ** Return the number of rows inserted. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && pParse->nested==0 && !pParse->trigStack ){
    sqlite3VdbeAddOp2(v, OP_ResultRow, iCntMem, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows inserted", P4_STATIC);
  }

insert_cleanup:
  sqlite3SrcListDelete(pTabList);
  sqlite3ExprListDelete(pList);
  sqlite3SelectDelete(pSelect);
  sqlite3IdListDelete(pColumn);
................................................................................
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    if( onError==OE_Replace && pTab->aCol[i].pDflt==0 ){
      onError = OE_Abort;
    }
    sqlite3VdbeAddOp2(v, OP_Dup, nCol-1-i, 1);
    addr = sqlite3VdbeAddOp2(v, OP_NotNull, 1, 0);
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        char *zMsg = 0;
        sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_CONSTRAINT, onError);
        sqlite3SetString(&zMsg, pTab->zName, ".", pTab->aCol[i].zName,
                        " may not be NULL", (char*)0);
        sqlite3VdbeChangeP4(v, -1, zMsg, P4_DYNAMIC);
        break;
      }
      case OE_Ignore: {
        sqlite3VdbeAddOp2(v, OP_Pop, nCol+1+hasTwoRowids, 0);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        break;
      }
      case OE_Replace: {
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
        sqlite3VdbeAddOp2(v, OP_Push, nCol-i, 0);
        break;
      }
    }
    sqlite3VdbeJumpHere(v, addr);
  }

  /* Test all CHECK constraints
................................................................................
    assert( pParse->ckOffset==0 );
    pParse->ckOffset = nCol;
    sqlite3ExprIfTrue(pParse, pTab->pCheck, allOk, 1);
    assert( pParse->ckOffset==nCol );
    pParse->ckOffset = 0;
    onError = overrideError!=OE_Default ? overrideError : OE_Abort;
    if( onError==OE_Ignore ){
      sqlite3VdbeAddOp2(v, OP_Pop, nCol+1+hasTwoRowids, 0);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
    }else{
      sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_CONSTRAINT, onError);
    }
    sqlite3VdbeResolveLabel(v, allOk);
  }
#endif /* !defined(SQLITE_OMIT_CHECK) */

  /* If we have an INTEGER PRIMARY KEY, make sure the primary key
  ** of the new record does not previously exist.  Except, if this
................................................................................
    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    
    if( isUpdate ){
      sqlite3VdbeAddOp2(v, OP_Dup, nCol+1, 1);
      sqlite3VdbeAddOp2(v, OP_Dup, nCol+1, 1);
      jumpInst1 = sqlite3VdbeAddOp2(v, OP_Eq, 0, 0);
    }
    sqlite3VdbeAddOp2(v, OP_Dup, nCol, 1);
    jumpInst2 = sqlite3VdbeAddOp2(v, OP_NotExists, base, 0);
    switch( onError ){
      default: {
        onError = OE_Abort;
        /* Fall thru into the next case */
      }
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
                         "PRIMARY KEY must be unique", P4_STATIC);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowIndexDelete(v, pTab, base, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp2(v, OP_Dup, nCol+hasTwoRowids, 1);
          sqlite3VdbeAddOp2(v, OP_MoveGe, base, 0);
        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp2(v, OP_Pop, nCol+1+hasTwoRowids, 0);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        break;
      }
    }
    sqlite3VdbeJumpHere(v, jumpInst2);
    if( isUpdate ){
      sqlite3VdbeJumpHere(v, jumpInst1);
      sqlite3VdbeAddOp2(v, OP_Dup, nCol+1, 1);
      sqlite3VdbeAddOp2(v, OP_MoveGe, base, 0);
    }
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */
  extra = -1;
  for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
    if( aIdxUsed && aIdxUsed[iCur]==0 ) continue;  /* Skip unused indices */
    extra++;

    /* Create a key for accessing the index entry */
    sqlite3VdbeAddOp2(v, OP_Dup, nCol+extra, 1);
    for(i=0; i<pIdx->nColumn; i++){
      int idx = pIdx->aiColumn[i];
      if( idx==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_Dup, i+extra+nCol+1, 1);
      }else{
        sqlite3VdbeAddOp2(v, OP_Dup, i+extra+nCol-idx, 1);
      }
    }
    jumpInst1 = sqlite3VdbeAddOp2(v, OP_MakeIdxRec, pIdx->nColumn, 0);
    sqlite3IndexAffinityStr(v, pIdx);

    /* Find out what action to take in case there is an indexing conflict */
    onError = pIdx->onError;
    if( onError==OE_None ) continue;  /* pIdx is not a UNIQUE index */
    if( overrideError!=OE_Default ){
      onError = overrideError;
................................................................................
    if( seenReplace ){
      if( onError==OE_Ignore ) onError = OE_Replace;
      else if( onError==OE_Fail ) onError = OE_Abort;
    }
    

    /* Check to see if the new index entry will be unique */
    sqlite3VdbeAddOp2(v, OP_Dup, extra+nCol+1+hasTwoRowids, 1);
    jumpInst2 = sqlite3VdbeAddOp2(v, OP_IsUnique, base+iCur+1, 0);

    /* Generate code that executes if the new index entry is not unique */
    assert( onError==OE_Rollback || onError==OE_Abort || onError==OE_Fail
        || onError==OE_Ignore || onError==OE_Replace );
    switch( onError ){
      case OE_Rollback:
      case OE_Abort:
................................................................................
          }else{
            sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], "%s", zCol);
            n1 += n2;
          }
        }
        sqlite3_snprintf(sizeof(zErrMsg)-n1, &zErrMsg[n1], 
            pIdx->nColumn>1 ? " are not unique" : " is not unique");
        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0, zErrMsg,0);
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp2(v, OP_Pop, nCol+extra+3+hasTwoRowids, 0);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowDelete(pParse->db, v, pTab, base, 0);
        if( isUpdate ){
          sqlite3VdbeAddOp2(v, OP_Dup, nCol+extra+1+hasTwoRowids, 1);
          sqlite3VdbeAddOp2(v, OP_MoveGe, base, 0);
        }
        seenReplace = 1;
        break;
      }
    }
#if NULL_DISTINCT_FOR_UNIQUE
    sqlite3VdbeJumpHere(v, jumpInst1);
................................................................................

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
  for(i=nIdx-1; i>=0; i--){
    if( aIdxUsed && aIdxUsed[i]==0 ) continue;
    sqlite3VdbeAddOp2(v, OP_IdxInsert, base+i+1, 0);
  }
  sqlite3VdbeAddOp2(v, OP_MakeRecord, pTab->nCol, 0);
  sqlite3TableAffinityStr(v, pTab);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){
    sqlite3VdbeAddOp2(v, OP_Dup, 1, 0);
    sqlite3VdbeAddOp2(v, OP_Dup, 1, 0);
    sqlite3VdbeAddOp2(v, OP_Insert, newIdx, 0);
  }
#endif
  if( pParse->nested ){
    pik_flags = 0;
  }else{
    pik_flags = OPFLAG_NCHANGE;
    pik_flags |= (isUpdate?OPFLAG_ISUPDATE:OPFLAG_LASTROWID);
  }
  if( appendBias ){
    pik_flags |= OPFLAG_APPEND;
  }
  sqlite3VdbeAddOp2(v, OP_Insert, base, pik_flags);
  if( !pParse->nested ){
    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_STATIC);
  }
  
  if( isUpdate && rowidChng ){
    sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
  }
}

/*
** Generate code that will open cursors for a table and for all
** indices of that table.  The "base" parameter is the cursor number used
** for the table.  Indices are opened on subsequent cursors.
................................................................................
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  sqlite3OpenTable(pParse, base, iDb, pTab, op);
  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp2(v, OP_Integer, iDb, 0);
    VdbeComment((v, "%s", pIdx->zName));
    sqlite3VdbeAddOp4(v, op, i+base, pIdx->tnum, 0,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
  }
  if( pParse->nTab<=base+i ){
    pParse->nTab = base+i;
  }
}


................................................................................
    ** the rowids might change which will mess up indexing.
    **
    ** Or if the destination has a UNIQUE index and is not empty,
    ** we also disallow the transfer optimization because we cannot
    ** insure that all entries in the union of DEST and SRC will be
    ** unique.
    */
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iDest, 0);
    emptyDestTest = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
  }else{
    emptyDestTest = 0;
  }
  sqlite3OpenTable(pParse, iSrc, iDbSrc, pSrc, OP_OpenRead);
  emptySrcTest = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
  if( pDest->iPKey>=0 ){
    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Dup, 0, 0);
    addr2 = sqlite3VdbeAddOp2(v, OP_NotExists, iDest, 0);
    sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
                      "PRIMARY KEY must be unique", P4_STATIC);
    sqlite3VdbeJumpHere(v, addr2);
    autoIncStep(pParse, counterMem);
  }else if( pDest->pIndex==0 ){
    addr1 = sqlite3VdbeAddOp2(v, OP_NewRowid, iDest, 0);
  }else{
    addr1 = sqlite3VdbeAddOp2(v, OP_Rowid, iSrc, 0);
    assert( pDest->autoInc==0 );
  }
  sqlite3VdbeAddOp2(v, OP_RowData, iSrc, 0);
  sqlite3VdbeAddOp4(v, OP_Insert, iDest, 0,
                    OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND,
                    pDest->zName, 0);
  sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1);
  autoIncEnd(pParse, iDbDest, pDest, counterMem);
  for(pDestIdx=pDest->pIndex; pDestIdx; pDestIdx=pDestIdx->pNext){
    for(pSrcIdx=pSrc->pIndex; pSrcIdx; pSrcIdx=pSrcIdx->pNext){
      if( xferCompatibleIndex(pDestIdx, pSrcIdx) ) break;
    }
    assert( pSrcIdx );
    sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
    sqlite3VdbeAddOp2(v, OP_Integer, iDbSrc, 0);
    pKey = sqlite3IndexKeyinfo(pParse, pSrcIdx);
    VdbeComment((v, "%s", pSrcIdx->zName));
    sqlite3VdbeAddOp4(v, OP_OpenRead, iSrc, pSrcIdx->tnum, 0,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    sqlite3VdbeAddOp2(v, OP_Integer, iDbDest, 0);
    pKey = sqlite3IndexKeyinfo(pParse, pDestIdx);
    VdbeComment((v, "%s", pDestIdx->zName));
    sqlite3VdbeAddOp4(v, OP_OpenWrite, iDest, pDestIdx->tnum, 0,
                      (char*)pKey, P4_KEYINFO_HANDOFF);
    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_RowKey, iSrc, 0);
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iDest, 1);
    sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
  }
  sqlite3VdbeJumpHere(v, emptySrcTest);
  sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
  sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
  if( emptyDestTest ){
    sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_OK, 0);
    sqlite3VdbeJumpHere(v, emptyDestTest);
    sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);
    return 0;
  }else{
    return 1;
  }
}
#endif /* SQLITE_OMIT_XFER_OPT */

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.154 2008/01/02 00:34:37 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)
................................................................................

/*
** Generate code to return a single integer value.
*/
static void returnSingleInt(Parse *pParse, const char *zLabel, int value){
  Vdbe *v = sqlite3GetVdbe(pParse);
  int mem = pParse->nMem++;
  sqlite3VdbeAddOp(v, OP_MemInt, value, mem);
  if( pParse->explain==0 ){
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, P3_STATIC);
  }
  sqlite3VdbeAddOp(v, OP_ResultRow, mem, 1);
}

#ifndef SQLITE_OMIT_FLAG_PRAGMAS
/*
** Check to see if zRight and zLeft refer to a pragma that queries
** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
** Also, implement the pragma.
................................................................................
            db->flags &= ~p->mask;
          }

          /* Many of the flag-pragmas modify the code generated by the SQL 
          ** compiler (eg. count_changes). So add an opcode to expire all
          ** compiled SQL statements after modifying a pragma value.
          */
          sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
        }
      }

      return 1;
    }
  }
  return 0;
................................................................................
      { OP_Callback,    1, 0,        0},
    };
    int addr;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeUsesBtree(v, iDb);
    if( !zRight ){
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P3_STATIC);
      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+5, SQLITE_DEFAULT_CACHE_SIZE);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp(v, OP_Integer, size, 0);
      sqlite3VdbeAddOp(v, OP_ReadCookie, iDb, 2);
      addr = sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeAddOp(v, OP_Ge, 0, addr+3);
      sqlite3VdbeAddOp(v, OP_Negative, 0, 0);
      sqlite3VdbeAddOp(v, OP_SetCookie, iDb, 2);
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
  }else

  /*
  **  PRAGMA [database.]page_size
................................................................................
    }

    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
      zRet = "exclusive";
    }
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P3_STATIC);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, zRet, 0);
    sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
  }else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [database.]auto_vacuum
  **  PRAGMA [database.]auto_vacuum=N
  **
................................................................................
    if( sqlite3ReadSchema(pParse) ){
      goto pragma_out;
    }
    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
      iLimit = 0x7fffffff;
    }
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3VdbeAddOp(v, OP_MemInt, iLimit, 0);
    addr = sqlite3VdbeAddOp(v, OP_IncrVacuum, iDb, 0);
    sqlite3VdbeAddOp(v, OP_Callback, 0, 0);
    sqlite3VdbeAddOp(v, OP_MemIncr, -1, 0);
    sqlite3VdbeAddOp(v, OP_IfMemPos, 0, addr);
    sqlite3VdbeJumpHere(v, addr);
  }else
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
  /*
  **  PRAGMA [database.]cache_size
................................................................................
  **
  */
  if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
    if( !zRight ){
      if( sqlite3_temp_directory ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "temp_store_directory", P3_STATIC);
        sqlite3VdbeOp3(v, OP_String8, 0, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
      }
    }else{
      if( zRight[0] 
       && !sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE) 
      ){
        sqlite3ErrorMsg(pParse, "not a writable directory");
        goto pragma_out;
................................................................................
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      int i;
      int nHidden = 0;
      Column *pCol;
      sqlite3VdbeSetNumCols(v, 6);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P3_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P3_STATIC);
      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P3_STATIC);
      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P3_STATIC);
      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P3_STATIC);
      sqlite3ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        const Token *pDflt;
        if( IsHiddenColumn(pCol) ){
          nHidden++;
          continue;
        }
        sqlite3VdbeAddOp(v, OP_Integer, i-nHidden, 0);
        sqlite3VdbeOp3(v, OP_String8, 0, 0, pCol->zName, 0);
        sqlite3VdbeOp3(v, OP_String8, 0, 0,
           pCol->zType ? pCol->zType : "", 0);
        sqlite3VdbeAddOp(v, OP_Integer, pCol->notNull, 0);
        if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){
          sqlite3VdbeOp3(v, OP_String8, 0, 0, (char*)pDflt->z, pDflt->n);
        }else{
          sqlite3VdbeAddOp(v, OP_Null, 0, 0);
        }
        sqlite3VdbeAddOp(v, OP_Integer, pCol->isPrimKey, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 6, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pIdx = sqlite3FindIndex(db, zRight, zDb);
    if( pIdx ){
      int i;
      pTab = pIdx->pTable;
      sqlite3VdbeSetNumCols(v, 3);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P3_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P3_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P3_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite3VdbeAddOp(v, OP_Integer, i, 0);
        sqlite3VdbeAddOp(v, OP_Integer, cnum, 0);
        assert( pTab->nCol>cnum );
        sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->aCol[cnum].zName, 0);
        sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
................................................................................
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pIdx = pTab->pIndex;
      if( pIdx ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 3);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P3_STATIC);
        while(pIdx){
          sqlite3VdbeAddOp(v, OP_Integer, i, 0);
          sqlite3VdbeOp3(v, OP_String8, 0, 0, pIdx->zName, 0);
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->onError!=OE_None, 0);
          sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
          ++i;
          pIdx = pIdx->pNext;
        }
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
    int i;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 3);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P3_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite3VdbeAddOp(v, OP_Integer, i, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0, db->aDb[i].zName, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0,
           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
      sqlite3VdbeAddOp(v, OP_Callback, 3, 0);
    }
  }else

  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P3_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeAddOp(v, OP_Integer, i++, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0, pColl->zName, 0);
      sqlite3VdbeAddOp(v, OP_Callback, 2, 0);
    }
  }else
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE_OMIT_FOREIGN_KEY
  if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
    FKey *pFK;
................................................................................
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pFK = pTab->pFKey;
      if( pFK ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 5);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P3_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P3_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P3_STATIC);
        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P3_STATIC);
        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P3_STATIC);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            char *zCol = pFK->aCol[j].zCol;
            sqlite3VdbeAddOp(v, OP_Integer, i, 0);
            sqlite3VdbeAddOp(v, OP_Integer, j, 0);
            sqlite3VdbeOp3(v, OP_String8, 0, 0, pFK->zTo, 0);
            sqlite3VdbeOp3(v, OP_String8, 0, 0,
                             pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
            sqlite3VdbeOp3(v, zCol ? OP_String8 : OP_Null, 0, 0, zCol, 0);
            sqlite3VdbeAddOp(v, OP_Callback, 5, 0);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else
................................................................................
    };

    int isQuick = (zLeft[0]=='q');

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P3_STATIC);

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){
      mxErr = atoi(zRight);
      if( mxErr<=0 ){
        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
      }
    }
    sqlite3VdbeAddOp(v, OP_MemInt, mxErr, 0);

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;
      Hash *pTbls;
      int cnt = 0;

      if( OMIT_TEMPDB && i==1 ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
      sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Do an integrity check of the B-Tree
      */
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        sqlite3VdbeAddOp(v, OP_Integer, pTab->tnum, 0);
        cnt++;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->tnum, 0);
          cnt++;
        }
      }
      if( cnt==0 ) continue;
      sqlite3VdbeAddOp(v, OP_IntegrityCk, 0, i);
      addr = sqlite3VdbeAddOp(v, OP_IsNull, -1, 0);
      sqlite3VdbeOp3(v, OP_String8, 0, 0,
         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
         P3_DYNAMIC);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_Concat, 0, 0);
      sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Make sure all the indices are constructed correctly.
      */
      for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
        sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
        sqlite3VdbeJumpHere(v, addr);
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp(v, OP_MemInt, 0, 1);
        loopTop = sqlite3VdbeAddOp(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp(v, OP_MemIncr, 1, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_MemIncr,    -1,  0,  0},
            { OP_String8,     0,  0,  "rowid "},
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  " missing from index "},
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      2,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqlite3GenerateIndexKey(v, pIdx, 1);
          jmp2 = sqlite3VdbeAddOp(v, OP_Found, j+2, 0);
          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqlite3VdbeChangeP3(v, addr+4, pIdx->zName, P3_STATIC);
          sqlite3VdbeJumpHere(v, jmp2);
        }
        sqlite3VdbeAddOp(v, OP_Next, 1, loopTop+1);
        sqlite3VdbeJumpHere(v, loopTop);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          static const VdbeOpList cntIdx[] = {
             { OP_MemInt,       0,  2,  0},
             { OP_Rewind,       0,  0,  0},  /* 1 */
             { OP_MemIncr,      1,  2,  0},
             { OP_Next,         0,  0,  0},  /* 3 */
................................................................................
             { OP_MemIncr,     -1,  0,  0},
             { OP_String8,      0,  0,  "wrong # of entries in index "},
             { OP_String8,      0,  0,  0},  /* 9 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqlite3VdbeAddOp(v, OP_IfMemPos, 0, 0);
          sqlite3VdbeAddOp(v, OP_Halt, 0, 0);
          sqlite3VdbeJumpHere(v, addr);
          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqlite3VdbeChangeP1(v, addr+1, j+2);
          sqlite3VdbeChangeP2(v, addr+1, addr+4);
          sqlite3VdbeChangeP1(v, addr+3, j+2);
          sqlite3VdbeChangeP2(v, addr+3, addr+2);
          sqlite3VdbeJumpHere(v, addr+6);
          sqlite3VdbeChangeP3(v, addr+9, pIdx->zName, P3_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP1(v, addr+1, mxErr);
    sqlite3VdbeJumpHere(v, addr+2);
  }else
................................................................................
      { "UTF16",    0                  }, /* SQLITE_UTF16NATIVE */
      { 0, 0 }
    };
    const struct EncName *pEnc;
    if( !zRight ){    /* "PRAGMA encoding" */
      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P3_STATIC);
      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
      for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
        if( pEnc->enc==ENC(pParse->db) ){
          sqlite3VdbeChangeP3(v, -1, pEnc->zName, P3_STATIC);
          break;
        }
      }
      sqlite3VdbeAddOp(v, OP_Callback, 1, 0);
    }else{                        /* "PRAGMA encoding = XXX" */
      /* Only change the value of sqlite.enc if the database handle is not
      ** initialized. If the main database exists, the new sqlite.enc value
      ** will be overwritten when the schema is next loaded. If it does not
      ** already exists, it will be created to use the new encoding value.
      */
      if( 
................................................................................
        { OP_ReadCookie,      0,  0,  0},    /* 0 */
        { OP_Callback,        1,  0,  0}
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP2(v, addr, iCookie);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P3_TRANSIENT);
    }
  }else
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
................................................................................
  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static const char *const azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    Vdbe *v = sqlite3GetVdbe(pParse);
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P3_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P3_STATIC);
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      Pager *pPager;
      const char *zState = "unknown";
      int j;
      if( db->aDb[i].zName==0 ) continue;
      sqlite3VdbeOp3(v, OP_String8, 0, 0, db->aDb[i].zName, P3_STATIC);
      pBt = db->aDb[i].pBt;
      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
        zState = "closed";
      }else if( sqlite3_file_control(db, db->aDb[i].zName, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeOp3(v, OP_String8, 0, 0, zState, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_Callback, 2, 0);
    }
  }else
#endif

#ifdef SQLITE_SSE
  /*
  ** Check to see if the sqlite_statements table exists.  Create it
................................................................................
  {}

  if( v ){
    /* Code an OP_Expire at the end of each PRAGMA program to cause
    ** the VDBE implementing the pragma to expire. Most (all?) pragmas
    ** are only valid for a single execution.
    */
    sqlite3VdbeAddOp(v, OP_Expire, 1, 0);

    /*
    ** Reset the safety level, in case the fullfsync flag or synchronous
    ** setting changed.
    */
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    if( db->autoCommit ){

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.155 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/
#if !defined(SQLITE_OMIT_PRAGMA) && !defined(SQLITE_OMIT_PARSER)
................................................................................

/*
** Generate code to return a single integer value.
*/
static void returnSingleInt(Parse *pParse, const char *zLabel, int value){
  Vdbe *v = sqlite3GetVdbe(pParse);
  int mem = pParse->nMem++;
  sqlite3VdbeAddOp2(v, OP_MemInt, value, mem);
  if( pParse->explain==0 ){
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLabel, P4_STATIC);
  }
  sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
}

#ifndef SQLITE_OMIT_FLAG_PRAGMAS
/*
** Check to see if zRight and zLeft refer to a pragma that queries
** or changes one of the flags in db->flags.  Return 1 if so and 0 if not.
** Also, implement the pragma.
................................................................................
            db->flags &= ~p->mask;
          }

          /* Many of the flag-pragmas modify the code generated by the SQL 
          ** compiler (eg. count_changes). So add an opcode to expire all
          ** compiled SQL statements after modifying a pragma value.
          */
          sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
        }
      }

      return 1;
    }
  }
  return 0;
................................................................................
      { OP_Callback,    1, 0,        0},
    };
    int addr;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeUsesBtree(v, iDb);
    if( !zRight ){
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cache_size", P4_STATIC);
      addr = sqlite3VdbeAddOpList(v, ArraySize(getCacheSize), getCacheSize);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP1(v, addr+5, SQLITE_DEFAULT_CACHE_SIZE);
    }else{
      int size = atoi(zRight);
      if( size<0 ) size = -size;
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp2(v, OP_Integer, size, 0);
      sqlite3VdbeAddOp2(v, OP_ReadCookie, iDb, 2);
      addr = sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
      sqlite3VdbeAddOp2(v, OP_Ge, 0, addr+3);
      sqlite3VdbeAddOp2(v, OP_Negative, 0, 0);
      sqlite3VdbeAddOp2(v, OP_SetCookie, iDb, 2);
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
  }else

  /*
  **  PRAGMA [database.]page_size
................................................................................
    }

    assert(eMode==PAGER_LOCKINGMODE_NORMAL||eMode==PAGER_LOCKINGMODE_EXCLUSIVE);
    if( eMode==PAGER_LOCKINGMODE_EXCLUSIVE ){
      zRet = "exclusive";
    }
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "locking_mode", P4_STATIC);
    sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, zRet, 0);
    sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
  }else
#endif /* SQLITE_OMIT_PAGER_PRAGMAS */

  /*
  **  PRAGMA [database.]auto_vacuum
  **  PRAGMA [database.]auto_vacuum=N
  **
................................................................................
    if( sqlite3ReadSchema(pParse) ){
      goto pragma_out;
    }
    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
      iLimit = 0x7fffffff;
    }
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3VdbeAddOp2(v, OP_MemInt, iLimit, 0);
    addr = sqlite3VdbeAddOp2(v, OP_IncrVacuum, iDb, 0);
    sqlite3VdbeAddOp2(v, OP_Callback, 0, 0);
    sqlite3VdbeAddOp2(v, OP_MemIncr, -1, 0);
    sqlite3VdbeAddOp2(v, OP_IfMemPos, 0, addr);
    sqlite3VdbeJumpHere(v, addr);
  }else
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
  /*
  **  PRAGMA [database.]cache_size
................................................................................
  **
  */
  if( sqlite3StrICmp(zLeft, "temp_store_directory")==0 ){
    if( !zRight ){
      if( sqlite3_temp_directory ){
        sqlite3VdbeSetNumCols(v, 1);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, 
            "temp_store_directory", P4_STATIC);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, sqlite3_temp_directory, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
      }
    }else{
      if( zRight[0] 
       && !sqlite3OsAccess(db->pVfs, zRight, SQLITE_ACCESS_READWRITE) 
      ){
        sqlite3ErrorMsg(pParse, "not a writable directory");
        goto pragma_out;
................................................................................
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      int i;
      int nHidden = 0;
      Column *pCol;
      sqlite3VdbeSetNumCols(v, 6);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "cid", P4_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "type", P4_STATIC);
      sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "notnull", P4_STATIC);
      sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "dflt_value", P4_STATIC);
      sqlite3VdbeSetColName(v, 5, COLNAME_NAME, "pk", P4_STATIC);
      sqlite3ViewGetColumnNames(pParse, pTab);
      for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){
        const Token *pDflt;
        if( IsHiddenColumn(pCol) ){
          nHidden++;
          continue;
        }
        sqlite3VdbeAddOp2(v, OP_Integer, i-nHidden, 0);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pCol->zName, 0);
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
           pCol->zType ? pCol->zType : "", 0);
        sqlite3VdbeAddOp2(v, OP_Integer, pCol->notNull, 0);
        if( pCol->pDflt && (pDflt = &pCol->pDflt->span)->z ){
          sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, (char*)pDflt->z, pDflt->n);
        }else{
          sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        }
        sqlite3VdbeAddOp2(v, OP_Integer, pCol->isPrimKey, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 6, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_info")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    pIdx = sqlite3FindIndex(db, zRight, zDb);
    if( pIdx ){
      int i;
      pTab = pIdx->pTable;
      sqlite3VdbeSetNumCols(v, 3);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seqno", P4_STATIC);
      sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "cid", P4_STATIC);
      sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "name", P4_STATIC);
      for(i=0; i<pIdx->nColumn; i++){
        int cnum = pIdx->aiColumn[i];
        sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
        sqlite3VdbeAddOp2(v, OP_Integer, cnum, 0);
        assert( pTab->nCol>cnum );
        sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pTab->aCol[cnum].zName, 0);
        sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "index_list")==0 && zRight ){
    Index *pIdx;
    Table *pTab;
................................................................................
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pIdx = pTab->pIndex;
      if( pIdx ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 3);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "unique", P4_STATIC);
        while(pIdx){
          sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
          sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pIdx->zName, 0);
          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->onError!=OE_None, 0);
          sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
          ++i;
          pIdx = pIdx->pNext;
        }
      }
    }
  }else

  if( sqlite3StrICmp(zLeft, "database_list")==0 ){
    int i;
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 3);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
    sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "file", P4_STATIC);
    for(i=0; i<db->nDb; i++){
      if( db->aDb[i].pBt==0 ) continue;
      assert( db->aDb[i].zName!=0 );
      sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, db->aDb[i].zName, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
           sqlite3BtreeGetFilename(db->aDb[i].pBt), 0);
      sqlite3VdbeAddOp2(v, OP_Callback, 3, 0);
    }
  }else

  if( sqlite3StrICmp(zLeft, "collation_list")==0 ){
    int i = 0;
    HashElem *p;
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "seq", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "name", P4_STATIC);
    for(p=sqliteHashFirst(&db->aCollSeq); p; p=sqliteHashNext(p)){
      CollSeq *pColl = (CollSeq *)sqliteHashData(p);
      sqlite3VdbeAddOp2(v, OP_Integer, i++, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pColl->zName, 0);
      sqlite3VdbeAddOp2(v, OP_Callback, 2, 0);
    }
  }else
#endif /* SQLITE_OMIT_SCHEMA_PRAGMAS */

#ifndef SQLITE_OMIT_FOREIGN_KEY
  if( sqlite3StrICmp(zLeft, "foreign_key_list")==0 && zRight ){
    FKey *pFK;
................................................................................
    pTab = sqlite3FindTable(db, zRight, zDb);
    if( pTab ){
      v = sqlite3GetVdbe(pParse);
      pFK = pTab->pFKey;
      if( pFK ){
        int i = 0; 
        sqlite3VdbeSetNumCols(v, 5);
        sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "id", P4_STATIC);
        sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "seq", P4_STATIC);
        sqlite3VdbeSetColName(v, 2, COLNAME_NAME, "table", P4_STATIC);
        sqlite3VdbeSetColName(v, 3, COLNAME_NAME, "from", P4_STATIC);
        sqlite3VdbeSetColName(v, 4, COLNAME_NAME, "to", P4_STATIC);
        while(pFK){
          int j;
          for(j=0; j<pFK->nCol; j++){
            char *zCol = pFK->aCol[j].zCol;
            sqlite3VdbeAddOp2(v, OP_Integer, i, 0);
            sqlite3VdbeAddOp2(v, OP_Integer, j, 0);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, pFK->zTo, 0);
            sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
                              pTab->aCol[pFK->aCol[j].iFrom].zName, 0);
            sqlite3VdbeAddOp4(v, zCol ? OP_String8 : OP_Null, 0, 0, 0, zCol, 0);
            sqlite3VdbeAddOp2(v, OP_Callback, 5, 0);
          }
          ++i;
          pFK = pFK->pNextFrom;
        }
      }
    }
  }else
................................................................................
    };

    int isQuick = (zLeft[0]=='q');

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "integrity_check", P4_STATIC);

    /* Set the maximum error count */
    mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
    if( zRight ){
      mxErr = atoi(zRight);
      if( mxErr<=0 ){
        mxErr = SQLITE_INTEGRITY_CHECK_ERROR_MAX;
      }
    }
    sqlite3VdbeAddOp2(v, OP_MemInt, mxErr, 0);

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;
      Hash *pTbls;
      int cnt = 0;

      if( OMIT_TEMPDB && i==1 ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp2(v, OP_IfMemPos, 0, 0);
      sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Do an integrity check of the B-Tree
      */
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        sqlite3VdbeAddOp2(v, OP_Integer, pTab->tnum, 0);
        cnt++;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3VdbeAddOp2(v, OP_Integer, pIdx->tnum, 0);
          cnt++;
        }
      }
      if( cnt==0 ) continue;
      sqlite3VdbeAddOp2(v, OP_IntegrityCk, 0, i);
      addr = sqlite3VdbeAddOp2(v, OP_IsNull, -1, 0);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0,
         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
         P4_DYNAMIC);
      sqlite3VdbeAddOp2(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Concat, 0, 0);
      sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Make sure all the indices are constructed correctly.
      */
      for(x=sqliteHashFirst(pTbls); x && !isQuick; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        addr = sqlite3VdbeAddOp2(v, OP_IfMemPos, 0, 0);
        sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
        sqlite3VdbeJumpHere(v, addr);
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp2(v, OP_MemInt, 0, 1);
        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp2(v, OP_MemIncr, 1, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_MemIncr,    -1,  0,  0},
            { OP_String8,     0,  0,  "rowid "},
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  " missing from index "},
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      2,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqlite3GenerateIndexKey(v, pIdx, 1);
          jmp2 = sqlite3VdbeAddOp2(v, OP_Found, j+2, 0);
          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_STATIC);
          sqlite3VdbeJumpHere(v, jmp2);
        }
        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
        sqlite3VdbeJumpHere(v, loopTop);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          static const VdbeOpList cntIdx[] = {
             { OP_MemInt,       0,  2,  0},
             { OP_Rewind,       0,  0,  0},  /* 1 */
             { OP_MemIncr,      1,  2,  0},
             { OP_Next,         0,  0,  0},  /* 3 */
................................................................................
             { OP_MemIncr,     -1,  0,  0},
             { OP_String8,      0,  0,  "wrong # of entries in index "},
             { OP_String8,      0,  0,  0},  /* 9 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqlite3VdbeAddOp2(v, OP_IfMemPos, 0, 0);
          sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
          sqlite3VdbeJumpHere(v, addr);
          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqlite3VdbeChangeP1(v, addr+1, j+2);
          sqlite3VdbeChangeP2(v, addr+1, addr+4);
          sqlite3VdbeChangeP1(v, addr+3, j+2);
          sqlite3VdbeChangeP2(v, addr+3, addr+2);
          sqlite3VdbeJumpHere(v, addr+6);
          sqlite3VdbeChangeP4(v, addr+9, pIdx->zName, P4_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP1(v, addr+1, mxErr);
    sqlite3VdbeJumpHere(v, addr+2);
  }else
................................................................................
      { "UTF16",    0                  }, /* SQLITE_UTF16NATIVE */
      { 0, 0 }
    };
    const struct EncName *pEnc;
    if( !zRight ){    /* "PRAGMA encoding" */
      if( sqlite3ReadSchema(pParse) ) goto pragma_out;
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "encoding", P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_String8, 0, 0);
      for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
        if( pEnc->enc==ENC(pParse->db) ){
          sqlite3VdbeChangeP4(v, -1, pEnc->zName, P4_STATIC);
          break;
        }
      }
      sqlite3VdbeAddOp2(v, OP_Callback, 1, 0);
    }else{                        /* "PRAGMA encoding = XXX" */
      /* Only change the value of sqlite.enc if the database handle is not
      ** initialized. If the main database exists, the new sqlite.enc value
      ** will be overwritten when the schema is next loaded. If it does not
      ** already exists, it will be created to use the new encoding value.
      */
      if( 
................................................................................
        { OP_ReadCookie,      0,  0,  0},    /* 0 */
        { OP_Callback,        1,  0,  0}
      };
      int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
      sqlite3VdbeChangeP1(v, addr, iDb);
      sqlite3VdbeChangeP2(v, addr, iCookie);
      sqlite3VdbeSetNumCols(v, 1);
      sqlite3VdbeSetColName(v, 0, COLNAME_NAME, zLeft, P4_TRANSIENT);
    }
  }else
#endif /* SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS */

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
  /*
  ** Report the current state of file logs for all databases
................................................................................
  if( sqlite3StrICmp(zLeft, "lock_status")==0 ){
    static const char *const azLockName[] = {
      "unlocked", "shared", "reserved", "pending", "exclusive"
    };
    int i;
    Vdbe *v = sqlite3GetVdbe(pParse);
    sqlite3VdbeSetNumCols(v, 2);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "database", P4_STATIC);
    sqlite3VdbeSetColName(v, 1, COLNAME_NAME, "status", P4_STATIC);
    for(i=0; i<db->nDb; i++){
      Btree *pBt;
      Pager *pPager;
      const char *zState = "unknown";
      int j;
      if( db->aDb[i].zName==0 ) continue;
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, db->aDb[i].zName, P4_STATIC);
      pBt = db->aDb[i].pBt;
      if( pBt==0 || (pPager = sqlite3BtreePager(pBt))==0 ){
        zState = "closed";
      }else if( sqlite3_file_control(db, db->aDb[i].zName, 
                                     SQLITE_FCNTL_LOCKSTATE, &j)==SQLITE_OK ){
         zState = azLockName[j];
      }
      sqlite3VdbeAddOp4(v, OP_String8, 0, 0, 0, zState, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_Callback, 2, 0);
    }
  }else
#endif

#ifdef SQLITE_SSE
  /*
  ** Check to see if the sqlite_statements table exists.  Create it
................................................................................
  {}

  if( v ){
    /* Code an OP_Expire at the end of each PRAGMA program to cause
    ** the VDBE implementing the pragma to expire. Most (all?) pragmas
    ** are only valid for a single execution.
    */
    sqlite3VdbeAddOp2(v, OP_Expire, 1, 0);

    /*
    ** Reset the safety level, in case the fullfsync flag or synchronous
    ** setting changed.
    */
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
    if( db->autoCommit ){

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.68 2007/12/27 15:12:17 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  }
  rc = sParse.rc;

#ifndef SQLITE_OMIT_EXPLAIN
  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
    if( sParse.explain==2 ){
      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P3_STATIC);
    }else{
      sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P3_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P3_STATIC);
    }
  }
#endif

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

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the implementation of the sqlite3_prepare()
** interface, and routines that contribute to loading the database schema
** from disk.
**
** $Id: prepare.c,v 1.69 2008/01/03 00:01:24 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Fill the InitData structure with an error message that indicates
** that the database is corrupt.
................................................................................
  }
  rc = sParse.rc;

#ifndef SQLITE_OMIT_EXPLAIN
  if( rc==SQLITE_OK && sParse.pVdbe && sParse.explain ){
    if( sParse.explain==2 ){
      sqlite3VdbeSetNumCols(sParse.pVdbe, 3);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "order", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "from", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "detail", P4_STATIC);
    }else{
      sqlite3VdbeSetNumCols(sParse.pVdbe, 5);
      sqlite3VdbeSetColName(sParse.pVdbe, 0, COLNAME_NAME, "addr", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 1, COLNAME_NAME, "opcode", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 2, COLNAME_NAME, "p1", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 3, COLNAME_NAME, "p2", P4_STATIC);
      sqlite3VdbeSetColName(sParse.pVdbe, 4, COLNAME_NAME, "p3", P4_STATIC);
    }
  }
#endif

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

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.377 2008/01/02 17:11:14 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................
static void pushOntoSorter(
  Parse *pParse,         /* Parser context */
  ExprList *pOrderBy,    /* The ORDER BY clause */
  Select *pSelect        /* The whole SELECT statement */
){
  Vdbe *v = pParse->pVdbe;
  sqlite3ExprCodeExprList(pParse, pOrderBy);
  sqlite3VdbeAddOp(v, OP_Sequence, pOrderBy->iECursor, 0);
  sqlite3VdbeAddOp(v, OP_Pull, pOrderBy->nExpr + 1, 0);
  sqlite3VdbeAddOp(v, OP_MakeRecord, pOrderBy->nExpr + 2, 0);
  sqlite3VdbeAddOp(v, OP_IdxInsert, pOrderBy->iECursor, 0);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    addr1 = sqlite3VdbeAddOp(v, OP_IfMemZero, pSelect->iLimit+1, 0);
    sqlite3VdbeAddOp(v, OP_MemIncr, -1, pSelect->iLimit+1);
    addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp(v, OP_Last, pOrderBy->iECursor, 0);
    sqlite3VdbeAddOp(v, OP_Delete, pOrderBy->iECursor, 0);
    sqlite3VdbeJumpHere(v, addr2);
    pSelect->iLimit = -1;
  }
}

/*
** Add code to implement the OFFSET
................................................................................
  Vdbe *v,          /* Generate code into this VM */
  Select *p,        /* The SELECT statement being coded */
  int iContinue,    /* Jump here to skip the current record */
  int nPop          /* Number of times to pop stack when jumping */
){
  if( p->iOffset>=0 && iContinue!=0 ){
    int addr;
    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iOffset);
    addr = sqlite3VdbeAddOp(v, OP_IfMemNeg, p->iOffset, 0);
    if( nPop>0 ){
      sqlite3VdbeAddOp(v, OP_Pop, nPop, 0);
    }
    sqlite3VdbeAddOp(v, OP_Goto, 0, iContinue);
    VdbeComment((v, "skip OFFSET records"));
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Add code that will check to make sure the top N elements of the
................................................................................
*/
static void codeDistinct_OLD(
  Vdbe *v,           /* Generate code into this VM */
  int iTab,          /* A sorting index used to test for distinctness */
  int addrRepeat,    /* Jump to here if not distinct */
  int N              /* The top N elements of the stack must be distinct */
){
  sqlite3VdbeAddOp(v, OP_MakeRecord, -N, 0);
  sqlite3VdbeAddOp(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp(v, OP_Pop, N+1, 0);
  sqlite3VdbeAddOp(v, OP_Goto, 0, addrRepeat);
  VdbeComment((v, "skip indistinct records"));
  sqlite3VdbeAddOp(v, OP_IdxInsert, iTab, 0);
}

/*
** Add code that will check to make sure the top N elements of the
** stack are distinct.  iTab is a sorting index that holds previously
** seen combinations of the N values.  A new entry is made in iTab
** if the current N values are new.
................................................................................
*/
static void codeDistinct(
  Vdbe *v,           /* Generate code into this VM */
  int iTab,          /* A sorting index used to test for distinctness */
  int addrRepeat,    /* Jump to here if not distinct */
  int iMem           /* First element */
){
  sqlite3VdbeAddOp(v, OP_RegMakeRec, iMem, 0);
  sqlite3VdbeAddOp(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
  sqlite3VdbeAddOp(v, OP_Goto, 0, addrRepeat);
  VdbeComment((v, "skip indistinct records"));
  sqlite3VdbeAddOp(v, OP_IdxInsert, iTab, 0);
}

/*
** Generate an error message when a SELECT is used within a subexpression
** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
** column.  We do this in a subroutine because the error occurs in multiple
** places.
................................................................................
  if( nColumn>0 ){
    n = nColumn;
  }else{
    n = pEList->nExpr;
  }
  iMem = pParse->nMem;
  pParse->nMem += n+1;
  sqlite3VdbeAddOp(v, OP_MemInt, n, iMem);
  if( nColumn>0 ){
    for(i=0; i<nColumn; i++){
      sqlite3VdbeOp3Int(v, OP_Column, srcTab, i, iMem+i+1);
    }
  }else if( eDest!=SRT_Exists ){
    /* If the destination is an EXISTS(...) expression, the actual
    ** values returned by the SELECT are not required.
    */
    for(i=0; i<n; i++){
      sqlite3ExprIntoReg(pParse, pEList->a[i].pExpr, iMem+i+1);
................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
#ifndef SQLITE_OMIT_COMPOUND_SELECT
    case SRT_Union: {
      sqlite3VdbeAddOp(v, OP_RegMakeRec, iMem, 0);
      if( aff ){
        sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      }
      sqlite3VdbeAddOp(v, OP_IdxInsert, iParm, 0);
      break;
    }

    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_RegMakeRec, iMem, 0);
      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
      break;
    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp(v, OP_RegMakeRec, iMem, 0);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
        sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
        sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
      }
      break;
    }

#ifndef SQLITE_OMIT_SUBQUERY
    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
    ** item into the set table with bogus data.
    */
    case SRT_Set: {
      int addr2;

      assert( nColumn==1 );
      addr2 = sqlite3VdbeAddOp(v, OP_IfMemNull, iMem+1, 0);
      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
      if( pOrderBy ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        sqlite3VdbeAddOp(v, OP_MemLoad, iMem+1, 0);
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeOp3(v, OP_RegMakeRec, iMem, 0, &p->affinity, 1);
        sqlite3VdbeAddOp(v, OP_IdxInsert, iParm, 0);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

    /* If any row exist in the result set, record that fact and abort.
    */
    case SRT_Exists: {
      sqlite3VdbeAddOp(v, OP_MemInt, 1, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out
    ** of the scan loop.
    */
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemLoad, iMem+1, 0);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
        /* The LIMIT clause will jump out of the loop for us */
      }
      break;
    }
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */

    /* Send the data to the callback function or to a subroutine.  In the
    ** case of a subroutine, the subroutine itself is responsible for
    ** popping the data from the stack.
    */
    case SRT_Subroutine:
    case SRT_Callback: {
      if( pOrderBy ){
        sqlite3VdbeAddOp(v, OP_RegMakeRec, iMem, 0);
        pushOntoSorter(pParse, pOrderBy, p);
      }else if( eDest==SRT_Subroutine ){
        for(i=0; i<nColumn; i++) sqlite3VdbeAddOp(v, OP_MemLoad, iMem+i+1, 0);
        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp(v, OP_ResultRow, iMem+1, nColumn);
      }
      break;
    }

#if !defined(SQLITE_OMIT_TRIGGER)
    /* Discard the results.  This is used for SELECT statements inside
    ** the body of a TRIGGER.  The purpose of such selects is to call
................................................................................
    }
#endif
  }

  /* Jump to the end of the loop if the LIMIT is reached.
  */
  if( p->iLimit>=0 && pOrderBy==0 ){
    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
    sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, iBreak);
  }
  return 0;
}

/*
** Given an expression list, generate a KeyInfo structure that records
** the collating sequence for each expression in that expression list.
................................................................................
** KeyInfo structure is appropriate for initializing a virtual index to
** implement that clause.  If the ExprList is the result set of a SELECT
** then the KeyInfo structure is appropriate for initializing a virtual
** index to implement a DISTINCT test.
**
** Space to hold the KeyInfo structure is obtain from malloc.  The calling
** function is responsible for seeing that this structure is eventually
** freed.  Add the KeyInfo structure to the P3 field of an opcode using
** P3_KEYINFO_HANDOFF is the usual way of dealing with this.
*/
static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
  sqlite3 *db = pParse->db;
  int nExpr;
  KeyInfo *pInfo;
  struct ExprList_item *pItem;
  int i;
................................................................................

  int eDest = pDest->eDest;
  int iParm = pDest->iParm;

  iTab = pOrderBy->iECursor;
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp(v, OP_OpenPseudo, pseudoTab, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, pseudoTab, nColumn);
  }
  addr = 1 + sqlite3VdbeAddOp(v, OP_Sort, iTab, brk);
  codeOffset(v, p, cont, 0);
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
  }
  sqlite3VdbeAddOp(v, OP_Column, iTab, pOrderBy->nExpr + 1);
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
      sqlite3VdbeAddOp(v, OP_IdxInsert, iParm, 0);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    case SRT_Callback:
    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp(v, OP_Insert, pseudoTab, 0);
      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp(v, OP_Column, pseudoTab, i);
      }
      if( eDest==SRT_Callback ){
        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
      }else{
        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
      }
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }

  /* Jump to the end of the loop when the LIMIT is reached
  */
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
    sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, brk);
  }

  /* The bottom of the loop
  */
  sqlite3VdbeResolveLabel(v, cont);
  sqlite3VdbeAddOp(v, OP_Next, iTab, addr);
  sqlite3VdbeResolveLabel(v, brk);
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    sqlite3VdbeAddOp(v, OP_Close, pseudoTab, 0);
  }

}

/*
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
................................................................................
    const char *zOrigCol = 0;
    const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);

    /* The vdbe must make its own copy of the column-type and other 
    ** column specific strings, in case the schema is reset before this
    ** virtual machine is deleted.
    */
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P3_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P3_TRANSIENT);
  }
}

/*
** Generate code that will tell the VDBE the names of columns
** in the result set.  This information is used to provide the
** azCol[] values in the callback.
................................................................................
      }else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
        char *zName = 0;
        char *zTab;
 
        zTab = pTabList->a[j].zAlias;
        if( fullNames || zTab==0 ) zTab = pTab->zName;
        sqlite3SetString(&zName, zTab, ".", zCol, (char*)0);
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P3_DYNAMIC);
      }else{
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
      }
    }else if( p->span.z && p->span.z[0] ){
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
      /* sqlite3VdbeCompressSpace(v, addr); */
    }else{
................................................................................
  */
  if( p->pLimit ){
    p->iLimit = iLimit = pParse->nMem;
    pParse->nMem += 2;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pLimit);
    sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iLimit, 1);
    VdbeComment((v, "LIMIT counter"));
    sqlite3VdbeAddOp(v, OP_IfMemZero, iLimit, iBreak);
    sqlite3VdbeAddOp(v, OP_MemLoad, iLimit, 0);
  }
  if( p->pOffset ){
    p->iOffset = iOffset = pParse->nMem++;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pOffset);
    sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iOffset, p->pLimit==0);
    VdbeComment((v, "OFFSET counter"));
    addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iOffset, 0);
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    if( p->pLimit ){
      sqlite3VdbeAddOp(v, OP_Add, 0, 0);
    }
  }
  if( p->pLimit ){
    addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iLimit, 0);
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_MemInt, -1, iLimit+1);
    addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp(v, OP_MemStore, iLimit+1, 1);
    VdbeComment((v, "LIMIT+OFFSET"));
    sqlite3VdbeJumpHere(v, addr2);
  }
}

/*
** Allocate a virtual index to use for sorting.
*/
static void createSortingIndex(Parse *pParse, Select *p, ExprList *pOrderBy){
  if( pOrderBy ){
    int addr;
    assert( pOrderBy->iECursor==0 );
    pOrderBy->iECursor = pParse->nTab++;
    addr = sqlite3VdbeAddOp(pParse->pVdbe, OP_OpenEphemeral,
                            pOrderBy->iECursor, pOrderBy->nExpr+1);
    assert( p->addrOpenEphm[2] == -1 );
    p->addrOpenEphm[2] = addr;
  }
}

#ifndef SQLITE_OMIT_COMPOUND_SELECT
................................................................................
  }

  /* Create the destination temporary table if necessary
  */
  if( dest.eDest==SRT_EphemTab ){
    assert( p->pEList );
    assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
    aSetP2[nSetP2++] = sqlite3VdbeAddOp(v, OP_OpenEphemeral, dest.iParm, 0);
    dest.eDest = SRT_Table;
  }

  /* Generate code for the left and right SELECT statements.
  */
  pOrderBy = p->pOrderBy;
  switch( p->op ){
................................................................................
        if( rc ){
          goto multi_select_end;
        }
        p->pPrior = 0;
        p->iLimit = pPrior->iLimit;
        p->iOffset = pPrior->iOffset;
        if( p->iLimit>=0 ){
          addr = sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, 0);
          VdbeComment((v, "Jump ahead if LIMIT reached"));
        }
        rc = sqlite3Select(pParse, p, &dest, 0, 0, 0, aff);
        p->pPrior = pPrior;
        if( rc ){
          goto multi_select_end;
        }
................................................................................
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        if( processCompoundOrderBy(pParse, p, unionTab) ){
          rc = 1;
          goto multi_select_end;
        }
        addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, unionTab, 0);
        if( priorOp==SRT_Table ){
          assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
          aSetP2[nSetP2++] = addr;
        }else{
          assert( p->addrOpenEphm[0] == -1 );
          p->addrOpenEphm[0] = addr;
          p->pRightmost->usesEphm = 1;
................................................................................
          Select *pFirst = p;
          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
          generateColumnNames(pParse, 0, pFirst->pEList);
        }
        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
        iStart = sqlite3VdbeCurrentAddr(v);
        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
                             pOrderBy, -1, &dest, iCont, iBreak, 0);
        if( rc ){
          rc = 1;
          goto multi_select_end;
        }
        sqlite3VdbeResolveLabel(v, iCont);
        sqlite3VdbeAddOp(v, OP_Next, unionTab, iStart);
        sqlite3VdbeResolveLabel(v, iBreak);
        sqlite3VdbeAddOp(v, OP_Close, unionTab, 0);
      }
      break;
    }
    case TK_INTERSECT: {
      int tab1, tab2;
      int iCont, iBreak, iStart;
      Expr *pLimit, *pOffset;
................................................................................
      tab2 = pParse->nTab++;
      if( processCompoundOrderBy(pParse, p, tab1) ){
        rc = 1;
        goto multi_select_end;
      }
      createSortingIndex(pParse, p, pOrderBy);

      addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab1, 0);
      assert( p->addrOpenEphm[0] == -1 );
      p->addrOpenEphm[0] = addr;
      p->pRightmost->usesEphm = 1;
      assert( p->pEList );

      /* Code the SELECTs to our left into temporary table "tab1".
      */
................................................................................
      rc = sqlite3Select(pParse, pPrior, &intersectdest, 0, 0, 0, aff);
      if( rc ){
        goto multi_select_end;
      }

      /* Code the current SELECT into temporary table "tab2"
      */
      addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab2, 0);
      assert( p->addrOpenEphm[1] == -1 );
      p->addrOpenEphm[1] = addr;
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;
      pOffset = p->pOffset;
      p->pOffset = 0;
................................................................................
        Select *pFirst = p;
        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
        generateColumnNames(pParse, 0, pFirst->pEList);
      }
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
      iStart = sqlite3VdbeAddOp(v, OP_RowKey, tab1, 0);
      sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
                             pOrderBy, -1, &dest, iCont, iBreak, 0);
      if( rc ){
        rc = 1;
        goto multi_select_end;
      }
      sqlite3VdbeResolveLabel(v, iCont);
      sqlite3VdbeAddOp(v, OP_Next, tab1, iStart);
      sqlite3VdbeResolveLabel(v, iBreak);
      sqlite3VdbeAddOp(v, OP_Close, tab2, 0);
      sqlite3VdbeAddOp(v, OP_Close, tab1, 0);
      break;
    }
  }

  /* Make sure all SELECTs in the statement have the same number of elements
  ** in their result sets.
  */
................................................................................
        if( addr<0 ){
          /* If [0] is unused then [1] is also unused.  So we can
          ** always safely abort as soon as the first unused slot is found */
          assert( pLoop->addrOpenEphm[1]<0 );
          break;
        }
        sqlite3VdbeChangeP2(v, addr, nCol);
        sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO);
        pLoop->addrOpenEphm[i] = -1;
      }
    }

    if( pOrderBy ){
      struct ExprList_item *pOTerm = pOrderBy->a;
      int nOrderByExpr = pOrderBy->nExpr;
................................................................................
        *pSortOrder = pOTerm->sortOrder;
      }
      assert( p->pRightmost==p );
      assert( p->addrOpenEphm[2]>=0 );
      addr = p->addrOpenEphm[2];
      sqlite3VdbeChangeP2(v, addr, p->pOrderBy->nExpr+2);
      pKeyInfo->nField = nOrderByExpr;
      sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
      pKeyInfo = 0;
      generateSortTail(pParse, p, v, p->pEList->nExpr, &dest);
    }

    sqlite3_free(pKeyInfo);
  }

................................................................................
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return 0;

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp(v, OP_OpenEphemeral, pDest->iParm, 1);
  }

  /* Generating code to find the min or the max.  Basically all we have
  ** to do is find the first or the last entry in the chosen index.  If
  ** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
  ** or last entry in the main table.
  */
................................................................................
  base = pSrc->a[0].iCursor;
  brk = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, brk);
  if( pSrc->a[0].pSelect==0 ){
    sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
  }
  if( pIdx==0 ){
    sqlite3VdbeAddOp(v, seekOp, base, 0);
  }else{
    /* Even though the cursor used to open the index here is closed
    ** as soon as a single value has been read from it, allocate it
    ** using (pParse->nTab++) to prevent the cursor id from being 
    ** reused. This is important for statements of the form 
    ** "INSERT INTO x SELECT max() FROM x".
    */
    int iIdx;
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    iIdx = pParse->nTab++;
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
    sqlite3VdbeOp3(v, OP_OpenRead, iIdx, pIdx->tnum, 
        (char*)pKey, P3_KEYINFO_HANDOFF);
    if( seekOp==OP_Rewind ){
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp(v, OP_MakeRecord, 1, 0);
      seekOp = OP_MoveGt;
    }
    if( pIdx->aSortOrder[0]==SQLITE_SO_DESC ){
      /* Ticket #2514: invert the seek operator if we are using
      ** a descending index. */
      if( seekOp==OP_Last ){
        seekOp = OP_Rewind;
      }else{
        assert( seekOp==OP_MoveGt );
        seekOp = OP_MoveLt;
      }
    }
    sqlite3VdbeAddOp(v, seekOp, iIdx, 0);
    sqlite3VdbeAddOp(v, OP_IdxRowid, iIdx, 0);
    sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
    sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
  }
  eList.nExpr = 1;
  memset(&eListItem, 0, sizeof(eListItem));
  eList.a = &eListItem;
  eList.a[0].pExpr = pExpr;
  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, pDest, brk, brk, 0);
  sqlite3VdbeResolveLabel(v, brk);
  sqlite3VdbeAddOp(v, OP_Close, base, 0);
  
  return 1;
}

/*
** This routine resolves any names used in the result set of the
** supplied SELECT statement. If the SELECT statement being resolved
................................................................................
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pFunc;
  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
    return;
  }
  for(i=0; i<pAggInfo->nColumn; i++){
    sqlite3VdbeAddOp(v, OP_MemNull, 0, pAggInfo->aCol[i].iMem);
  }
  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
    sqlite3VdbeAddOp(v, OP_MemNull, 0, pFunc->iMem);
    if( pFunc->iDistinct>=0 ){
      Expr *pE = pFunc->pExpr;
      if( pE->pList==0 || pE->pList->nExpr!=1 ){
        sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
           "by an expression");
        pFunc->iDistinct = -1;
      }else{
        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
        sqlite3VdbeOp3(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 
                          (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
      }
    }
  }
}

/*
** Invoke the OP_AggFinalize opcode for every aggregate function
................................................................................
*/
static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pF;
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    ExprList *pList = pF->pExpr->pList;
    sqlite3VdbeOp3(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0,
                      (void*)pF->pFunc, P3_FUNCDEF);
  }
}

/*
** Update the accumulator memory cells for an aggregate based on
** the current cursor position.
*/
................................................................................
      assert( pList!=0 );  /* pList!=0 if pF->pFunc->needCollSeq is true */
      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
      }
      if( !pColl ){
        pColl = pParse->db->pDfltColl;
      }
      sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
    }
    sqlite3VdbeOp3(v, OP_AggStep, pF->iMem, nArg, (void*)pF->pFunc, P3_FUNCDEF);

    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
    }
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pExpr);
    sqlite3VdbeAddOp(v, OP_MemStore, pC->iMem, 1);
  }
  pAggInfo->directMode = 0;
}

#ifndef SQLITE_OMIT_TRIGGER
/*
** This function is used when a SELECT statement is used to create a
................................................................................
    KeyInfo *pKeyInfo;
    if( pParse->nErr ){
      goto select_end;
    }
    pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
    pOrderBy->iECursor = pParse->nTab++;
    p->addrOpenEphm[2] = addrSortIndex =

      sqlite3VdbeOp3(v, OP_OpenEphemeral, pOrderBy->iECursor, pOrderBy->nExpr+2,                     (char*)pKeyInfo, P3_KEYINFO_HANDOFF);

  }else{
    addrSortIndex = -1;
  }

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp(v, OP_OpenEphemeral, pDest->iParm, pEList->nExpr);
  }

  /* Set the limiter.
  */
  iEnd = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, iEnd);

................................................................................
  /* Open a virtual index to use for the distinct set.
  */
  if( isDistinct ){
    KeyInfo *pKeyInfo;
    assert( isAgg || pGroupBy );
    distinct = pParse->nTab++;
    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
    sqlite3VdbeOp3(v, OP_OpenEphemeral, distinct, 0, 
                        (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
  }else{
    distinct = -1;
  }

  /* Aggregate and non-aggregate queries are handled differently */
  if( !isAgg && pGroupBy==0 ){
    /* This case is for non-aggregate queries
................................................................................
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OpenEphemeral instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
      addrSortingIdx =
          sqlite3VdbeOp3(v, OP_OpenEphemeral, sAggInfo.sortingIdx,
                         sAggInfo.nSortingColumn,
                         (char*)pKeyInfo, P3_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = pParse->nMem++;
      iAbortFlag = pParse->nMem++;
      iAMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      iBMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      sqlite3VdbeAddOp(v, OP_MemInt, 0, iAbortFlag);
      VdbeComment((v, "clear abort flag"));
      sqlite3VdbeAddOp(v, OP_MemInt, 0, iUseFlag);
      VdbeComment((v, "indicate accumulator empty"));
      sqlite3VdbeAddOp(v, OP_Goto, 0, addrInitializeLoop);

      /* Generate a subroutine that outputs a single row of the result
      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
      ** is less than or equal to zero, the subroutine is a no-op.  If
      ** the processing calls for the query to abort, this subroutine
      ** increments the iAbortFlag memory location before returning in
      ** order to signal the caller to abort.
      */
      addrSetAbort = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_MemInt, 1, iAbortFlag);
      VdbeComment((v, "set abort flag"));
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
      addrOutputRow = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_IfMemPos, iUseFlag, addrOutputRow+2);
      VdbeComment((v, "Groupby result generator entry point"));
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
      finalizeAggFunctions(pParse, &sAggInfo);
      if( pHaving ){
        sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, 1);
      }
      rc = selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
                           distinct, pDest,
                           addrOutputRow+1, addrSetAbort, aff);
      if( rc ){
        goto select_end;
      }
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
      VdbeComment((v, "end groupby result generator"));

      /* Generate a subroutine that will reset the group-by accumulator
      */
      addrReset = sqlite3VdbeCurrentAddr(v);
      resetAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);

      /* Begin a loop that will extract all source rows in GROUP BY order.
      ** This might involve two separate loops with an OP_Sort in between, or
      ** it might be a single loop that uses an index to extract information
      ** in the right order to begin with.
      */
      sqlite3VdbeResolveLabel(v, addrInitializeLoop);
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy);
      if( pWInfo==0 ) goto select_end;
      if( pGroupBy==0 ){
        /* The optimizer is able to deliver rows in group by order so
        ** we do not have to sort.  The OP_OpenEphemeral table will be
        ** cancelled later because we still need to use the pKeyInfo
        */
................................................................................
        /* Rows are coming out in undetermined order.  We have to push
        ** each row into a sorting index, terminate the first loop,
        ** then loop over the sorting index in order to get the output
        ** in sorted order
        */
        groupBySort = 1;
        sqlite3ExprCodeExprList(pParse, pGroupBy);
        sqlite3VdbeAddOp(v, OP_Sequence, sAggInfo.sortingIdx, 0);
        j = pGroupBy->nExpr+1;
        for(i=0; i<sAggInfo.nColumn; i++){
          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
          if( pCol->iSorterColumn<j ) continue;
          sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable);
          j++;
        }
        sqlite3VdbeAddOp(v, OP_MakeRecord, j, 0);
        sqlite3VdbeAddOp(v, OP_IdxInsert, sAggInfo.sortingIdx, 0);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
      }

      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
      ** Then compare the current GROUP BY terms against the GROUP BY terms
      ** from the previous row currently stored in a0, a1, a2...
      */
      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
      for(j=0; j<pGroupBy->nExpr; j++){
        if( groupBySort ){
          sqlite3VdbeAddOp(v, OP_Column, sAggInfo.sortingIdx, j);
        }else{
          sAggInfo.directMode = 1;
          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr);
        }
        sqlite3VdbeAddOp(v, OP_MemStore, iBMem+j, j<pGroupBy->nExpr-1);
      }
      for(j=pGroupBy->nExpr-1; j>=0; j--){
        if( j<pGroupBy->nExpr-1 ){
          sqlite3VdbeAddOp(v, OP_MemLoad, iBMem+j, 0);
        }
        sqlite3VdbeAddOp(v, OP_MemLoad, iAMem+j, 0);
        if( j==0 ){
          sqlite3VdbeAddOp(v, OP_Eq, 0x200, addrProcessRow);
        }else{
          sqlite3VdbeAddOp(v, OP_Ne, 0x200, addrGroupByChange);
        }
        sqlite3VdbeChangeP3(v, -1, (void*)pKeyInfo->aColl[j], P3_COLLSEQ);
      }

      /* Generate code that runs whenever the GROUP BY changes.
      ** Change in the GROUP BY are detected by the previous code
      ** block.  If there were no changes, this block is skipped.
      **
      ** This code copies current group by terms in b0,b1,b2,...
      ** over to a0,a1,a2.  It then calls the output subroutine
      ** and resets the aggregate accumulator registers in preparation
      ** for the next GROUP BY batch.
      */
      sqlite3VdbeResolveLabel(v, addrGroupByChange);
      for(j=0; j<pGroupBy->nExpr; j++){
        sqlite3VdbeAddOp(v, OP_MemMove, iAMem+j, iBMem+j);
      }
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
      VdbeComment((v, "output one row"));
      sqlite3VdbeAddOp(v, OP_IfMemPos, iAbortFlag, addrEnd);
      VdbeComment((v, "check abort flag"));
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
      VdbeComment((v, "reset accumulator"));

      /* Update the aggregate accumulators based on the content of
      ** the current row
      */
      sqlite3VdbeResolveLabel(v, addrProcessRow);
      updateAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp(v, OP_MemInt, 1, iUseFlag);
      VdbeComment((v, "indicate data in accumulator"));

      /* End of the loop
      */
      if( groupBySort ){
        sqlite3VdbeAddOp(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
      }else{
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
      }

      /* Output the final row of result
      */
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
      VdbeComment((v, "output final row"));
      
    } /* endif pGroupBy */
    else {
      /* This case runs if the aggregate has no GROUP BY clause.  The
      ** processing is much simpler since there is only a single row
      ** of output.

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.378 2008/01/03 00:01:25 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.
................................................................................
static void pushOntoSorter(
  Parse *pParse,         /* Parser context */
  ExprList *pOrderBy,    /* The ORDER BY clause */
  Select *pSelect        /* The whole SELECT statement */
){
  Vdbe *v = pParse->pVdbe;
  sqlite3ExprCodeExprList(pParse, pOrderBy);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, 0);
  sqlite3VdbeAddOp2(v, OP_Pull, pOrderBy->nExpr + 1, 0);
  sqlite3VdbeAddOp2(v, OP_MakeRecord, pOrderBy->nExpr + 2, 0);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, 0);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    addr1 = sqlite3VdbeAddOp2(v, OP_IfMemZero, pSelect->iLimit+1, 0);
    sqlite3VdbeAddOp2(v, OP_MemIncr, -1, pSelect->iLimit+1);
    addr2 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp2(v, OP_Last, pOrderBy->iECursor, 0);
    sqlite3VdbeAddOp2(v, OP_Delete, pOrderBy->iECursor, 0);
    sqlite3VdbeJumpHere(v, addr2);
    pSelect->iLimit = -1;
  }
}

/*
** Add code to implement the OFFSET
................................................................................
  Vdbe *v,          /* Generate code into this VM */
  Select *p,        /* The SELECT statement being coded */
  int iContinue,    /* Jump here to skip the current record */
  int nPop          /* Number of times to pop stack when jumping */
){
  if( p->iOffset>=0 && iContinue!=0 ){
    int addr;
    sqlite3VdbeAddOp2(v, OP_MemIncr, -1, p->iOffset);
    addr = sqlite3VdbeAddOp2(v, OP_IfMemNeg, p->iOffset, 0);
    if( nPop>0 ){
      sqlite3VdbeAddOp2(v, OP_Pop, nPop, 0);
    }
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue);
    VdbeComment((v, "skip OFFSET records"));
    sqlite3VdbeJumpHere(v, addr);
  }
}

/*
** Add code that will check to make sure the top N elements of the
................................................................................
*/
static void codeDistinct_OLD(
  Vdbe *v,           /* Generate code into this VM */
  int iTab,          /* A sorting index used to test for distinctness */
  int addrRepeat,    /* Jump to here if not distinct */
  int N              /* The top N elements of the stack must be distinct */
){
  sqlite3VdbeAddOp2(v, OP_MakeRecord, -N, 0);
  sqlite3VdbeAddOp2(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp2(v, OP_Pop, N+1, 0);
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrRepeat);
  VdbeComment((v, "skip indistinct records"));
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, 0);
}

/*
** Add code that will check to make sure the top N elements of the
** stack are distinct.  iTab is a sorting index that holds previously
** seen combinations of the N values.  A new entry is made in iTab
** if the current N values are new.
................................................................................
*/
static void codeDistinct(
  Vdbe *v,           /* Generate code into this VM */
  int iTab,          /* A sorting index used to test for distinctness */
  int addrRepeat,    /* Jump to here if not distinct */
  int iMem           /* First element */
){
  sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, 0);
  sqlite3VdbeAddOp2(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrRepeat);
  VdbeComment((v, "skip indistinct records"));
  sqlite3VdbeAddOp2(v, OP_IdxInsert, iTab, 0);
}

/*
** Generate an error message when a SELECT is used within a subexpression
** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
** column.  We do this in a subroutine because the error occurs in multiple
** places.
................................................................................
  if( nColumn>0 ){
    n = nColumn;
  }else{
    n = pEList->nExpr;
  }
  iMem = pParse->nMem;
  pParse->nMem += n+1;
  sqlite3VdbeAddOp2(v, OP_MemInt, n, iMem);
  if( nColumn>0 ){
    for(i=0; i<nColumn; i++){
      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, iMem+i+1);
    }
  }else if( eDest!=SRT_Exists ){
    /* If the destination is an EXISTS(...) expression, the actual
    ** values returned by the SELECT are not required.
    */
    for(i=0; i<n; i++){
      sqlite3ExprIntoReg(pParse, pEList->a[i].pExpr, iMem+i+1);
................................................................................

  switch( eDest ){
    /* In this mode, write each query result to the key of the temporary
    ** table iParm.
    */
#ifndef SQLITE_OMIT_COMPOUND_SELECT
    case SRT_Union: {
      sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, 0);
      if( aff ){
        sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      }
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      break;
    }

    /* Construct a record from the query result, but instead of
    ** saving that record, use it as a key to delete elements from
    ** the temporary table iParm.
    */
    case SRT_Except: {
      int addr;
      addr = sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, 0);
      sqlite3VdbeChangeP4(v, -1, aff, P4_STATIC);
      sqlite3VdbeAddOp2(v, OP_NotFound, iParm, addr+3);
      sqlite3VdbeAddOp2(v, OP_Delete, iParm, 0);
      break;
    }
#endif

    /* Store the result as data using a unique key.
    */
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, 0);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, 0);
        sqlite3VdbeAddOp2(v, OP_Pull, 1, 0);
        sqlite3VdbeAddOp2(v, OP_Insert, iParm, OPFLAG_APPEND);
      }
      break;
    }

#ifndef SQLITE_OMIT_SUBQUERY
    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
    ** then there should be a single item on the stack.  Write this
    ** item into the set table with bogus data.
    */
    case SRT_Set: {
      int addr2;

      assert( nColumn==1 );
      addr2 = sqlite3VdbeAddOp2(v, OP_IfMemNull, iMem+1, 0);
      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affinity);
      if( pOrderBy ){
        /* At first glance you would think we could optimize out the
        ** ORDER BY in this case since the order of entries in the set
        ** does not matter.  But there might be a LIMIT clause, in which
        ** case the order does matter */
        sqlite3VdbeAddOp2(v, OP_MemLoad, iMem+1, 0);
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeAddOp4(v, OP_RegMakeRec, iMem, 0, 0, &p->affinity, 1);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

    /* If any row exist in the result set, record that fact and abort.
    */
    case SRT_Exists: {
      sqlite3VdbeAddOp2(v, OP_MemInt, 1, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out
    ** of the scan loop.
    */
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_MemLoad, iMem+1, 0);
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p);
      }else{
        sqlite3VdbeAddOp2(v, OP_MemStore, iParm, 1);
        /* The LIMIT clause will jump out of the loop for us */
      }
      break;
    }
#endif /* #ifndef SQLITE_OMIT_SUBQUERY */

    /* Send the data to the callback function or to a subroutine.  In the
    ** case of a subroutine, the subroutine itself is responsible for
    ** popping the data from the stack.
    */
    case SRT_Subroutine:
    case SRT_Callback: {
      if( pOrderBy ){
        sqlite3VdbeAddOp2(v, OP_RegMakeRec, iMem, 0);
        pushOntoSorter(pParse, pOrderBy, p);
      }else if( eDest==SRT_Subroutine ){
        for(i=0; i<nColumn; i++) sqlite3VdbeAddOp2(v, OP_MemLoad, iMem+i+1, 0);
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, iMem+1, nColumn);
      }
      break;
    }

#if !defined(SQLITE_OMIT_TRIGGER)
    /* Discard the results.  This is used for SELECT statements inside
    ** the body of a TRIGGER.  The purpose of such selects is to call
................................................................................
    }
#endif
  }

  /* Jump to the end of the loop if the LIMIT is reached.
  */
  if( p->iLimit>=0 && pOrderBy==0 ){
    sqlite3VdbeAddOp2(v, OP_MemIncr, -1, p->iLimit);
    sqlite3VdbeAddOp2(v, OP_IfMemZero, p->iLimit, iBreak);
  }
  return 0;
}

/*
** Given an expression list, generate a KeyInfo structure that records
** the collating sequence for each expression in that expression list.
................................................................................
** KeyInfo structure is appropriate for initializing a virtual index to
** implement that clause.  If the ExprList is the result set of a SELECT
** then the KeyInfo structure is appropriate for initializing a virtual
** index to implement a DISTINCT test.
**
** Space to hold the KeyInfo structure is obtain from malloc.  The calling
** function is responsible for seeing that this structure is eventually
** freed.  Add the KeyInfo structure to the P4 field of an opcode using
** P4_KEYINFO_HANDOFF is the usual way of dealing with this.
*/
static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
  sqlite3 *db = pParse->db;
  int nExpr;
  KeyInfo *pInfo;
  struct ExprList_item *pItem;
  int i;
................................................................................

  int eDest = pDest->eDest;
  int iParm = pDest->iParm;

  iTab = pOrderBy->iECursor;
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    pseudoTab = pParse->nTab++;
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, pseudoTab, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, pseudoTab, nColumn);
  }
  addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, brk);
  codeOffset(v, p, cont, 0);
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    sqlite3VdbeAddOp2(v, OP_Integer, 1, 0);
  }
  sqlite3VdbeAddOp2(v, OP_Column, iTab, pOrderBy->nExpr + 1);
  switch( eDest ){
    case SRT_Table:
    case SRT_EphemTab: {
      sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, 0);
      sqlite3VdbeAddOp2(v, OP_Pull, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Insert, iParm, OPFLAG_APPEND);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
      sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
      sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &p->affinity, 1);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, 0);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3VdbeAddOp2(v, OP_MemStore, iParm, 1);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    case SRT_Callback:
    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp2(v, OP_Insert, pseudoTab, 0);
      for(i=0; i<nColumn; i++){
        sqlite3VdbeAddOp2(v, OP_Column, pseudoTab, i);
      }
      if( eDest==SRT_Callback ){
        sqlite3VdbeAddOp2(v, OP_Callback, nColumn, 0);
      }else{
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }
      break;
    }
    default: {
      /* Do nothing */
      break;
    }
  }

  /* Jump to the end of the loop when the LIMIT is reached
  */
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp2(v, OP_MemIncr, -1, p->iLimit);
    sqlite3VdbeAddOp2(v, OP_IfMemZero, p->iLimit, brk);
  }

  /* The bottom of the loop
  */
  sqlite3VdbeResolveLabel(v, cont);
  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr);
  sqlite3VdbeResolveLabel(v, brk);
  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
    sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0);
  }

}

/*
** Return a pointer to a string containing the 'declaration type' of the
** expression pExpr. The string may be treated as static by the caller.
................................................................................
    const char *zOrigCol = 0;
    const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);

    /* The vdbe must make its own copy of the column-type and other 
    ** column specific strings, in case the schema is reset before this
    ** virtual machine is deleted.
    */
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P4_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P4_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P4_TRANSIENT);
    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P4_TRANSIENT);
  }
}

/*
** Generate code that will tell the VDBE the names of columns
** in the result set.  This information is used to provide the
** azCol[] values in the callback.
................................................................................
      }else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
        char *zName = 0;
        char *zTab;
 
        zTab = pTabList->a[j].zAlias;
        if( fullNames || zTab==0 ) zTab = pTab->zName;
        sqlite3SetString(&zName, zTab, ".", zCol, (char*)0);
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P4_DYNAMIC);
      }else{
        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
      }
    }else if( p->span.z && p->span.z[0] ){
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
      /* sqlite3VdbeCompressSpace(v, addr); */
    }else{
................................................................................
  */
  if( p->pLimit ){
    p->iLimit = iLimit = pParse->nMem;
    pParse->nMem += 2;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pLimit);
    sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp2(v, OP_MemStore, iLimit, 1);
    VdbeComment((v, "LIMIT counter"));
    sqlite3VdbeAddOp2(v, OP_IfMemZero, iLimit, iBreak);
    sqlite3VdbeAddOp2(v, OP_MemLoad, iLimit, 0);
  }
  if( p->pOffset ){
    p->iOffset = iOffset = pParse->nMem++;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pOffset);
    sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp2(v, OP_MemStore, iOffset, p->pLimit==0);
    VdbeComment((v, "OFFSET counter"));
    addr1 = sqlite3VdbeAddOp2(v, OP_IfMemPos, iOffset, 0);
    sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp2(v, OP_Integer, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    if( p->pLimit ){
      sqlite3VdbeAddOp2(v, OP_Add, 0, 0);
    }
  }
  if( p->pLimit ){
    addr1 = sqlite3VdbeAddOp2(v, OP_IfMemPos, iLimit, 0);
    sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp2(v, OP_MemInt, -1, iLimit+1);
    addr2 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp2(v, OP_MemStore, iLimit+1, 1);
    VdbeComment((v, "LIMIT+OFFSET"));
    sqlite3VdbeJumpHere(v, addr2);
  }
}

/*
** Allocate a virtual index to use for sorting.
*/
static void createSortingIndex(Parse *pParse, Select *p, ExprList *pOrderBy){
  if( pOrderBy ){
    int addr;
    assert( pOrderBy->iECursor==0 );
    pOrderBy->iECursor = pParse->nTab++;
    addr = sqlite3VdbeAddOp2(pParse->pVdbe, OP_OpenEphemeral,
                            pOrderBy->iECursor, pOrderBy->nExpr+1);
    assert( p->addrOpenEphm[2] == -1 );
    p->addrOpenEphm[2] = addr;
  }
}

#ifndef SQLITE_OMIT_COMPOUND_SELECT
................................................................................
  }

  /* Create the destination temporary table if necessary
  */
  if( dest.eDest==SRT_EphemTab ){
    assert( p->pEList );
    assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
    aSetP2[nSetP2++] = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, dest.iParm, 0);
    dest.eDest = SRT_Table;
  }

  /* Generate code for the left and right SELECT statements.
  */
  pOrderBy = p->pOrderBy;
  switch( p->op ){
................................................................................
        if( rc ){
          goto multi_select_end;
        }
        p->pPrior = 0;
        p->iLimit = pPrior->iLimit;
        p->iOffset = pPrior->iOffset;
        if( p->iLimit>=0 ){
          addr = sqlite3VdbeAddOp2(v, OP_IfMemZero, p->iLimit, 0);
          VdbeComment((v, "Jump ahead if LIMIT reached"));
        }
        rc = sqlite3Select(pParse, p, &dest, 0, 0, 0, aff);
        p->pPrior = pPrior;
        if( rc ){
          goto multi_select_end;
        }
................................................................................
        ** intermediate results.
        */
        unionTab = pParse->nTab++;
        if( processCompoundOrderBy(pParse, p, unionTab) ){
          rc = 1;
          goto multi_select_end;
        }
        addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, unionTab, 0);
        if( priorOp==SRT_Table ){
          assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
          aSetP2[nSetP2++] = addr;
        }else{
          assert( p->addrOpenEphm[0] == -1 );
          p->addrOpenEphm[0] = addr;
          p->pRightmost->usesEphm = 1;
................................................................................
          Select *pFirst = p;
          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
          generateColumnNames(pParse, 0, pFirst->pEList);
        }
        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak);
        iStart = sqlite3VdbeCurrentAddr(v);
        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
                             pOrderBy, -1, &dest, iCont, iBreak, 0);
        if( rc ){
          rc = 1;
          goto multi_select_end;
        }
        sqlite3VdbeResolveLabel(v, iCont);
        sqlite3VdbeAddOp2(v, OP_Next, unionTab, iStart);
        sqlite3VdbeResolveLabel(v, iBreak);
        sqlite3VdbeAddOp2(v, OP_Close, unionTab, 0);
      }
      break;
    }
    case TK_INTERSECT: {
      int tab1, tab2;
      int iCont, iBreak, iStart;
      Expr *pLimit, *pOffset;
................................................................................
      tab2 = pParse->nTab++;
      if( processCompoundOrderBy(pParse, p, tab1) ){
        rc = 1;
        goto multi_select_end;
      }
      createSortingIndex(pParse, p, pOrderBy);

      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab1, 0);
      assert( p->addrOpenEphm[0] == -1 );
      p->addrOpenEphm[0] = addr;
      p->pRightmost->usesEphm = 1;
      assert( p->pEList );

      /* Code the SELECTs to our left into temporary table "tab1".
      */
................................................................................
      rc = sqlite3Select(pParse, pPrior, &intersectdest, 0, 0, 0, aff);
      if( rc ){
        goto multi_select_end;
      }

      /* Code the current SELECT into temporary table "tab2"
      */
      addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, tab2, 0);
      assert( p->addrOpenEphm[1] == -1 );
      p->addrOpenEphm[1] = addr;
      p->pPrior = 0;
      pLimit = p->pLimit;
      p->pLimit = 0;
      pOffset = p->pOffset;
      p->pOffset = 0;
................................................................................
        Select *pFirst = p;
        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
        generateColumnNames(pParse, 0, pFirst->pEList);
      }
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak);
      iStart = sqlite3VdbeAddOp2(v, OP_RowKey, tab1, 0);
      sqlite3VdbeAddOp2(v, OP_NotFound, tab2, iCont);
      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
                             pOrderBy, -1, &dest, iCont, iBreak, 0);
      if( rc ){
        rc = 1;
        goto multi_select_end;
      }
      sqlite3VdbeResolveLabel(v, iCont);
      sqlite3VdbeAddOp2(v, OP_Next, tab1, iStart);
      sqlite3VdbeResolveLabel(v, iBreak);
      sqlite3VdbeAddOp2(v, OP_Close, tab2, 0);
      sqlite3VdbeAddOp2(v, OP_Close, tab1, 0);
      break;
    }
  }

  /* Make sure all SELECTs in the statement have the same number of elements
  ** in their result sets.
  */
................................................................................
        if( addr<0 ){
          /* If [0] is unused then [1] is also unused.  So we can
          ** always safely abort as soon as the first unused slot is found */
          assert( pLoop->addrOpenEphm[1]<0 );
          break;
        }
        sqlite3VdbeChangeP2(v, addr, nCol);
        sqlite3VdbeChangeP4(v, addr, (char*)pKeyInfo, P4_KEYINFO);
        pLoop->addrOpenEphm[i] = -1;
      }
    }

    if( pOrderBy ){
      struct ExprList_item *pOTerm = pOrderBy->a;
      int nOrderByExpr = pOrderBy->nExpr;
................................................................................
        *pSortOrder = pOTerm->sortOrder;
      }
      assert( p->pRightmost==p );
      assert( p->addrOpenEphm[2]>=0 );
      addr = p->addrOpenEphm[2];
      sqlite3VdbeChangeP2(v, addr, p->pOrderBy->nExpr+2);
      pKeyInfo->nField = nOrderByExpr;
      sqlite3VdbeChangeP4(v, addr, (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
      pKeyInfo = 0;
      generateSortTail(pParse, p, v, p->pEList->nExpr, &dest);
    }

    sqlite3_free(pKeyInfo);
  }

................................................................................
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return 0;

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, 1);
  }

  /* Generating code to find the min or the max.  Basically all we have
  ** to do is find the first or the last entry in the chosen index.  If
  ** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
  ** or last entry in the main table.
  */
................................................................................
  base = pSrc->a[0].iCursor;
  brk = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, brk);
  if( pSrc->a[0].pSelect==0 ){
    sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
  }
  if( pIdx==0 ){
    sqlite3VdbeAddOp2(v, seekOp, base, 0);
  }else{
    /* Even though the cursor used to open the index here is closed
    ** as soon as a single value has been read from it, allocate it
    ** using (pParse->nTab++) to prevent the cursor id from being 
    ** reused. This is important for statements of the form 
    ** "INSERT INTO x SELECT max() FROM x".
    */
    int iIdx;
    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
    iIdx = pParse->nTab++;
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp2(v, OP_Integer, iDb, 0);
    sqlite3VdbeAddOp4(v, OP_OpenRead, iIdx, pIdx->tnum, 0,
        (char*)pKey, P4_KEYINFO_HANDOFF);
    if( seekOp==OP_Rewind ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp2(v, OP_MakeRecord, 1, 0);
      seekOp = OP_MoveGt;
    }
    if( pIdx->aSortOrder[0]==SQLITE_SO_DESC ){
      /* Ticket #2514: invert the seek operator if we are using
      ** a descending index. */
      if( seekOp==OP_Last ){
        seekOp = OP_Rewind;
      }else{
        assert( seekOp==OP_MoveGt );
        seekOp = OP_MoveLt;
      }
    }
    sqlite3VdbeAddOp2(v, seekOp, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_Close, iIdx, 0);
    sqlite3VdbeAddOp2(v, OP_MoveGe, base, 0);
  }
  eList.nExpr = 1;
  memset(&eListItem, 0, sizeof(eListItem));
  eList.a = &eListItem;
  eList.a[0].pExpr = pExpr;
  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, pDest, brk, brk, 0);
  sqlite3VdbeResolveLabel(v, brk);
  sqlite3VdbeAddOp2(v, OP_Close, base, 0);
  
  return 1;
}

/*
** This routine resolves any names used in the result set of the
** supplied SELECT statement. If the SELECT statement being resolved
................................................................................
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pFunc;
  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
    return;
  }
  for(i=0; i<pAggInfo->nColumn; i++){
    sqlite3VdbeAddOp2(v, OP_MemNull, 0, pAggInfo->aCol[i].iMem);
  }
  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
    sqlite3VdbeAddOp2(v, OP_MemNull, 0, pFunc->iMem);
    if( pFunc->iDistinct>=0 ){
      Expr *pE = pFunc->pExpr;
      if( pE->pList==0 || pE->pList->nExpr!=1 ){
        sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
           "by an expression");
        pFunc->iDistinct = -1;
      }else{
        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
        sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0,
                          (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
      }
    }
  }
}

/*
** Invoke the OP_AggFinalize opcode for every aggregate function
................................................................................
*/
static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pF;
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    ExprList *pList = pF->pExpr->pList;
    sqlite3VdbeAddOp4(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0, 0,
                      (void*)pF->pFunc, P4_FUNCDEF);
  }
}

/*
** Update the accumulator memory cells for an aggregate based on
** the current cursor position.
*/
................................................................................
      assert( pList!=0 );  /* pList!=0 if pF->pFunc->needCollSeq is true */
      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
      }
      if( !pColl ){
        pColl = pParse->db->pDfltColl;
      }
      sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
    }
    sqlite3VdbeAddOp4(v, OP_AggStep, pF->iMem, nArg, 0, 
                      (void*)pF->pFunc, P4_FUNCDEF);
    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
    }
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pExpr);
    sqlite3VdbeAddOp2(v, OP_MemStore, pC->iMem, 1);
  }
  pAggInfo->directMode = 0;
}

#ifndef SQLITE_OMIT_TRIGGER
/*
** This function is used when a SELECT statement is used to create a
................................................................................
    KeyInfo *pKeyInfo;
    if( pParse->nErr ){
      goto select_end;
    }
    pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
    pOrderBy->iECursor = pParse->nTab++;
    p->addrOpenEphm[2] = addrSortIndex =
      sqlite3VdbeAddOp4(v, OP_OpenEphemeral,
                           pOrderBy->iECursor, pOrderBy->nExpr+2, 0,
                           (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
  }else{
    addrSortIndex = -1;
  }

  /* If the output is destined for a temporary table, open that table.
  */
  if( pDest->eDest==SRT_EphemTab ){
    sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pDest->iParm, pEList->nExpr);
  }

  /* Set the limiter.
  */
  iEnd = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, iEnd);

................................................................................
  /* Open a virtual index to use for the distinct set.
  */
  if( isDistinct ){
    KeyInfo *pKeyInfo;
    assert( isAgg || pGroupBy );
    distinct = pParse->nTab++;
    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
    sqlite3VdbeAddOp4(v, OP_OpenEphemeral, distinct, 0, 0,
                        (char*)pKeyInfo, P4_KEYINFO_HANDOFF);
  }else{
    distinct = -1;
  }

  /* Aggregate and non-aggregate queries are handled differently */
  if( !isAgg && pGroupBy==0 ){
    /* This case is for non-aggregate queries
................................................................................
      ** implement it.  Allocate that sorting index now.  If it turns out
      ** that we do not need it after all, the OpenEphemeral instruction
      ** will be converted into a Noop.  
      */
      sAggInfo.sortingIdx = pParse->nTab++;
      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
      addrSortingIdx =
          sqlite3VdbeAddOp4(v, OP_OpenEphemeral, sAggInfo.sortingIdx,
                         sAggInfo.nSortingColumn, 0,
                         (char*)pKeyInfo, P4_KEYINFO_HANDOFF);

      /* Initialize memory locations used by GROUP BY aggregate processing
      */
      iUseFlag = pParse->nMem++;
      iAbortFlag = pParse->nMem++;
      iAMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      iBMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      sqlite3VdbeAddOp2(v, OP_MemInt, 0, iAbortFlag);
      VdbeComment((v, "clear abort flag"));
      sqlite3VdbeAddOp2(v, OP_MemInt, 0, iUseFlag);
      VdbeComment((v, "indicate accumulator empty"));
      sqlite3VdbeAddOp2(v, OP_Goto, 0, addrInitializeLoop);

      /* Generate a subroutine that outputs a single row of the result
      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
      ** is less than or equal to zero, the subroutine is a no-op.  If
      ** the processing calls for the query to abort, this subroutine
      ** increments the iAbortFlag memory location before returning in
      ** order to signal the caller to abort.
      */
      addrSetAbort = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_MemInt, 1, iAbortFlag);
      VdbeComment((v, "set abort flag"));
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      addrOutputRow = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_IfMemPos, iUseFlag, addrOutputRow+2);
      VdbeComment((v, "Groupby result generator entry point"));
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      finalizeAggFunctions(pParse, &sAggInfo);
      if( pHaving ){
        sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, 1);
      }
      rc = selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
                           distinct, pDest,
                           addrOutputRow+1, addrSetAbort, aff);
      if( rc ){
        goto select_end;
      }
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);
      VdbeComment((v, "end groupby result generator"));

      /* Generate a subroutine that will reset the group-by accumulator
      */
      addrReset = sqlite3VdbeCurrentAddr(v);
      resetAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp2(v, OP_Return, 0, 0);

      /* Begin a loop that will extract all source rows in GROUP BY order.
      ** This might involve two separate loops with an OP_Sort in between, or
      ** it might be a single loop that uses an index to extract information
      ** in the right order to begin with.
      */
      sqlite3VdbeResolveLabel(v, addrInitializeLoop);
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrReset);
      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy);
      if( pWInfo==0 ) goto select_end;
      if( pGroupBy==0 ){
        /* The optimizer is able to deliver rows in group by order so
        ** we do not have to sort.  The OP_OpenEphemeral table will be
        ** cancelled later because we still need to use the pKeyInfo
        */
................................................................................
        /* Rows are coming out in undetermined order.  We have to push
        ** each row into a sorting index, terminate the first loop,
        ** then loop over the sorting index in order to get the output
        ** in sorted order
        */
        groupBySort = 1;
        sqlite3ExprCodeExprList(pParse, pGroupBy);
        sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx, 0);
        j = pGroupBy->nExpr+1;
        for(i=0; i<sAggInfo.nColumn; i++){
          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
          if( pCol->iSorterColumn<j ) continue;
          sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable);
          j++;
        }
        sqlite3VdbeAddOp2(v, OP_MakeRecord, j, 0);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, 0);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
      }

      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
      ** Then compare the current GROUP BY terms against the GROUP BY terms
      ** from the previous row currently stored in a0, a1, a2...
      */
      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
      for(j=0; j<pGroupBy->nExpr; j++){
        if( groupBySort ){
          sqlite3VdbeAddOp2(v, OP_Column, sAggInfo.sortingIdx, j);
        }else{
          sAggInfo.directMode = 1;
          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr);
        }
        sqlite3VdbeAddOp2(v, OP_MemStore, iBMem+j, j<pGroupBy->nExpr-1);
      }
      for(j=pGroupBy->nExpr-1; j>=0; j--){
        if( j<pGroupBy->nExpr-1 ){
          sqlite3VdbeAddOp2(v, OP_MemLoad, iBMem+j, 0);
        }
        sqlite3VdbeAddOp2(v, OP_MemLoad, iAMem+j, 0);
        if( j==0 ){
          sqlite3VdbeAddOp2(v, OP_Eq, 0x200, addrProcessRow);
        }else{
          sqlite3VdbeAddOp2(v, OP_Ne, 0x200, addrGroupByChange);
        }
        sqlite3VdbeChangeP4(v, -1, (void*)pKeyInfo->aColl[j], P4_COLLSEQ);
      }

      /* Generate code that runs whenever the GROUP BY changes.
      ** Change in the GROUP BY are detected by the previous code
      ** block.  If there were no changes, this block is skipped.
      **
      ** This code copies current group by terms in b0,b1,b2,...
      ** over to a0,a1,a2.  It then calls the output subroutine
      ** and resets the aggregate accumulator registers in preparation
      ** for the next GROUP BY batch.
      */
      sqlite3VdbeResolveLabel(v, addrGroupByChange);
      for(j=0; j<pGroupBy->nExpr; j++){
        sqlite3VdbeAddOp2(v, OP_MemMove, iAMem+j, iBMem+j);
      }
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrOutputRow);
      VdbeComment((v, "output one row"));
      sqlite3VdbeAddOp2(v, OP_IfMemPos, iAbortFlag, addrEnd);
      VdbeComment((v, "check abort flag"));
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrReset);
      VdbeComment((v, "reset accumulator"));

      /* Update the aggregate accumulators based on the content of
      ** the current row
      */
      sqlite3VdbeResolveLabel(v, addrProcessRow);
      updateAccumulator(pParse, &sAggInfo);
      sqlite3VdbeAddOp2(v, OP_MemInt, 1, iUseFlag);
      VdbeComment((v, "indicate data in accumulator"));

      /* End of the loop
      */
      if( groupBySort ){
        sqlite3VdbeAddOp2(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
      }else{
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
      }

      /* Output the final row of result
      */
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrOutputRow);
      VdbeComment((v, "output final row"));
      
    } /* endif pGroupBy */
    else {
      /* This case runs if the aggregate has no GROUP BY clause.  The
      ** processing is much simpler since there is only a single row
      ** of output.

**    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 1.630 2008/01/02 17:11:14 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
................................................................................
**
** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
** the speed a little by number the values consecutively.  
**
** But rather than start with 0 or 1, we begin with 'a'.  That way,
** when multiple affinity types are concatenated into a string and
** used as the P3 operand, they will be more readable.
**
** Note also that the numeric types are grouped together so that testing
** for a numeric type is a single comparison.
*/
#define SQLITE_AFF_TEXT     'a'
#define SQLITE_AFF_NONE     'b'
#define SQLITE_AFF_NUMERIC  'c'
................................................................................
** If there is a LIMIT clause, the parser sets nLimit to the value of the
** limit and nOffset to the value of the offset (or 0 if there is not
** offset).  But later on, nLimit and nOffset become the memory locations
** in the VDBE that record the limit and offset counters.
**
** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
** These addresses must be stored so that we can go back and fill in
** the P3_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
** the number of columns in P2 can be computed at the same time
** as the OP_OpenEphm instruction is coded because not
** enough information about the compound query is known at that point.
** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
** sequences for the ORDER BY clause.
*/

**    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 1.631 2008/01/03 00:01:25 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds
................................................................................
**
** These used to have mnemonic name like 'i' for SQLITE_AFF_INTEGER and
** 't' for SQLITE_AFF_TEXT.  But we can save a little space and improve
** the speed a little by number the values consecutively.  
**
** But rather than start with 0 or 1, we begin with 'a'.  That way,
** when multiple affinity types are concatenated into a string and
** used as the P4 operand, they will be more readable.
**
** Note also that the numeric types are grouped together so that testing
** for a numeric type is a single comparison.
*/
#define SQLITE_AFF_TEXT     'a'
#define SQLITE_AFF_NONE     'b'
#define SQLITE_AFF_NUMERIC  'c'
................................................................................
** If there is a LIMIT clause, the parser sets nLimit to the value of the
** limit and nOffset to the value of the offset (or 0 if there is not
** offset).  But later on, nLimit and nOffset become the memory locations
** in the VDBE that record the limit and offset counters.
**
** addrOpenEphm[] entries contain the address of OP_OpenEphemeral opcodes.
** These addresses must be stored so that we can go back and fill in
** the P4_KEYINFO and P2 parameters later.  Neither the KeyInfo nor
** the number of columns in P2 can be computed at the same time
** as the OP_OpenEphm instruction is coded because not
** enough information about the compound query is known at that point.
** The KeyInfo for addrOpenTran[0] and [1] contains collating sequences
** for the result set.  The KeyInfo for addrOpenTran[2] contains collating
** sequences for the ORDER BY clause.
*/

  fs_vfs.base.szOsFile = MAX(sizeof(tmp_file), sizeof(fs_file));
  return sqlite3_vfs_register(&fs_vfs.base, 0);
}

#ifdef SQLITE_TEST
  int SqlitetestOnefile_Init() {return fs_register();}
#endif

  fs_vfs.base.szOsFile = MAX(sizeof(tmp_file), sizeof(fs_file));
  return sqlite3_vfs_register(&fs_vfs.base, 0);
}

#ifdef SQLITE_TEST
  int SqlitetestOnefile_Init() {return fs_register();}
#endif

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
    sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0); 
    sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0); 
    sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, sqlite3MPrintf(
        db, "type='trigger' AND name='%q'", pTrig->name), P3_DYNAMIC
    );
  }

  if( db->init.busy ){
    int n;
    Table *pTab;
    Trigger *pDel;
................................................................................
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);
    sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0);
  }
}

/*
** Remove a trigger from the hash tables of the sqlite* pointer.
*/
void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
................................................................................
  TriggerStep * pTriggerStep = pStepList;
  int orconf;
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;

  assert( pTriggerStep!=0 );
  assert( v!=0 );
  sqlite3VdbeAddOp(v, OP_ContextPush, 0, 0);
  VdbeComment((v, "begin trigger %s", pStepList->pTrig->name));
  while( pTriggerStep ){
    orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
    pParse->trigStack->orconf = orconf;
    switch( pTriggerStep->op ){
      case TK_SELECT: {
        Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect);
................................................................................
          sqlite3SelectDelete(ss);
        }
        break;
      }
      case TK_UPDATE: {
        SrcList *pSrc;
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
        sqlite3Update(pParse, pSrc,
                sqlite3ExprListDup(db, pTriggerStep->pExprList), 
                sqlite3ExprDup(db, pTriggerStep->pWhere), orconf);
        sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
        break;
      }
      case TK_INSERT: {
        SrcList *pSrc;
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
        sqlite3Insert(pParse, pSrc,
          sqlite3ExprListDup(db, pTriggerStep->pExprList), 
          sqlite3SelectDup(db, pTriggerStep->pSelect), 
          sqlite3IdListDup(db, pTriggerStep->pIdList), orconf);
        sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
        break;
      }
      case TK_DELETE: {
        SrcList *pSrc;
        sqlite3VdbeAddOp(v, OP_ResetCount, 0, 0);
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3DeleteFrom(pParse, pSrc, 
                          sqlite3ExprDup(db, pTriggerStep->pWhere));
        sqlite3VdbeAddOp(v, OP_ResetCount, 1, 0);
        break;
      }
      default:
        assert(0);
    } 
    pTriggerStep = pTriggerStep->pNext;
  }
  sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
  VdbeComment((v, "end trigger %s", pStepList->pTrig->name));

  return 0;
}

/*
** This is called to code FOR EACH ROW triggers.

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
    sqlite3VdbeChangeP4(v, addr+2, pTrig->name, 0); 
    sqlite3VdbeChangeP4(v, addr+3, pTrig->table, 0); 
    sqlite3VdbeChangeP4(v, addr+6, (char*)pAll->z, pAll->n);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
        db, "type='trigger' AND name='%q'", pTrig->name), P4_DYNAMIC
    );
  }

  if( db->init.busy ){
    int n;
    Table *pTab;
    Trigger *pDel;
................................................................................
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);
    sqlite3VdbeChangeP4(v, base+1, pTrigger->name, 0);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp2(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp4(v, OP_DropTrigger, iDb, 0, 0, pTrigger->name, 0);
  }
}

/*
** Remove a trigger from the hash tables of the sqlite* pointer.
*/
void sqlite3UnlinkAndDeleteTrigger(sqlite3 *db, int iDb, const char *zName){
................................................................................
  TriggerStep * pTriggerStep = pStepList;
  int orconf;
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;

  assert( pTriggerStep!=0 );
  assert( v!=0 );
  sqlite3VdbeAddOp2(v, OP_ContextPush, 0, 0);
  VdbeComment((v, "begin trigger %s", pStepList->pTrig->name));
  while( pTriggerStep ){
    orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
    pParse->trigStack->orconf = orconf;
    switch( pTriggerStep->op ){
      case TK_SELECT: {
        Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect);
................................................................................
          sqlite3SelectDelete(ss);
        }
        break;
      }
      case TK_UPDATE: {
        SrcList *pSrc;
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
        sqlite3Update(pParse, pSrc,
                sqlite3ExprListDup(db, pTriggerStep->pExprList), 
                sqlite3ExprDup(db, pTriggerStep->pWhere), orconf);
        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
        break;
      }
      case TK_INSERT: {
        SrcList *pSrc;
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
        sqlite3Insert(pParse, pSrc,
          sqlite3ExprListDup(db, pTriggerStep->pExprList), 
          sqlite3SelectDup(db, pTriggerStep->pSelect), 
          sqlite3IdListDup(db, pTriggerStep->pIdList), orconf);
        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
        break;
      }
      case TK_DELETE: {
        SrcList *pSrc;
        sqlite3VdbeAddOp2(v, OP_ResetCount, 0, 0);
        pSrc = targetSrcList(pParse, pTriggerStep);
        sqlite3DeleteFrom(pParse, pSrc, 
                          sqlite3ExprDup(db, pTriggerStep->pWhere));
        sqlite3VdbeAddOp2(v, OP_ResetCount, 1, 0);
        break;
      }
      default:
        assert(0);
    } 
    pTriggerStep = pTriggerStep->pNext;
  }
  sqlite3VdbeAddOp2(v, OP_ContextPop, 0, 0);
  VdbeComment((v, "end trigger %s", pStepList->pTrig->name));

  return 0;
}

/*
** This is called to code FOR EACH ROW triggers.

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.148 2008/01/02 16:27:10 danielk1977 Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
  Expr *pWhere         /* WHERE clause of the UPDATE statement */
);
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P3 parameter of the 
** OP_Column to the default value, if any.
**
** The default value of a column is specified by a DEFAULT clause in the 
** column definition. This was either supplied by the user when the table
** was created, or added later to the table definition by an ALTER TABLE
** command. If the latter, then the row-records in the table btree on disk
** may not contain a value for the column and the default value, taken
** from the P3 parameter of the OP_Column instruction, is returned instead.
** If the former, then all row-records are guaranteed to include a value
** for the column and the P3 value is not required.
**
** Column definitions created by an ALTER TABLE command may only have 
** literal default values specified: a number, null or a string. (If a more
** complicated default expression value was provided, it is evaluated 
** when the ALTER TABLE is executed and one of the literal values written
** into the sqlite_master table.)
**
** Therefore, the P3 parameter is only required if the default value for
** the column is a literal number, string or null. The sqlite3ValueFromExpr()
** function is capable of transforming these types of expressions into
** sqlite3_value objects.
*/
void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){
  if( pTab && !pTab->pSelect ){
    sqlite3_value *pValue;
................................................................................
    u8 enc = ENC(sqlite3VdbeDb(v));
    Column *pCol = &pTab->aCol[i];
    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
    assert( i<pTab->nCol );
    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
                         pCol->affinity, &pValue);
    if( pValue ){
      sqlite3VdbeAddOp(v, OP_DfltValue, 0, 0);
      sqlite3VdbeChangeP3(v, -1, (const char *)pValue, P3_MEM);
    }
  }
}

/*
** Process an UPDATE statement.
**
................................................................................
  /* Generate the code for triggers.
  */
  if( triggers_exist ){
    int iGoto;

    /* Create pseudo-tables for NEW and OLD
    */
    sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    sqlite3VdbeAddOp(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);

    iGoto = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndBeforeTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndAfterTrigger = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to update a view, realize that view into
  ** a ephemeral table.
  */
  if( isView ){
................................................................................
  /* Begin the database scan
  */
  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
  if( pWInfo==0 ) goto update_cleanup;

  /* Remember the rowid of every item to be updated.
  */
  sqlite3VdbeAddOp(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0);
  sqlite3VdbeAddOp(v, OP_FifoWrite, 0, 0);

  /* End the database scan loop.
  */
  sqlite3WhereEnd(pWInfo);

  /* Initialize the count of updated rows
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
    memCnt = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt);
  }

  if( !isView && !IsVirtual(pTab) ){
    /* 
    ** Open every index that needs updating.  Note that if any
    ** index could potentially invoke a REPLACE conflict resolution 
    ** action, then we need to open all indices because we might need
................................................................................
          break;
        }
      }
    }
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] ){
        KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
        sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
        sqlite3VdbeOp3(v, OP_OpenWrite, iCur+i+1, pIdx->tnum,
                       (char*)pKey, P3_KEYINFO_HANDOFF);
        assert( pParse->nTab>iCur+i+1 );
      }
    }

  }
  
  /* Jump back to this point if a trigger encounters an IGNORE constraint. */
  if( triggers_exist ){
    sqlite3VdbeResolveLabel(v, addr);
  }

  /* Top of the update loop */
  addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
  sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
  sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);

  if( triggers_exist ){
    /* Make cursor iCur point to the record that is being updated.
    */
    sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);

    /* Generate the OLD table
    */
    sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
    if( !old_col_mask ){
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    }else{
      sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
    }
    sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);

    /* Generate the NEW table
    */
    if( chngRowid ){
      sqlite3ExprCodeAndCache(pParse, pRowidExpr);
    }else{
      sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){
        if( j<0 ){
          sqlite3VdbeAddOp(v, OP_Column, iCur, i);
          sqlite3ColumnDefault(v, pTab, i);
        }else{
          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
        }
      }else{
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      }
    }
    sqlite3VdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    if( pParse->nErr ) goto update_cleanup;
    sqlite3VdbeAddOp(v, OP_Insert, newIdx, 0);

    sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginBeforeTrigger);
    sqlite3VdbeJumpHere(v, iEndBeforeTrigger);

    if( !isView ){
      sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
    }
  }

  if( !isView && !IsVirtual(pTab) ){

    /* Loop over every record that needs updating.  We have to load
    ** the old data for each record to be updated because some columns
    ** might not change and we will need to copy the old value.
    ** Also, the old data is needed to delete the old index entries.
    ** So make the cursor point at the old record.
    */
    sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
    sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);

    /* If the record number will change, push the record number as it
    ** will be after the update. (The old record number is currently
    ** on top of the stack.)
    */
    if( chngRowid ){
      sqlite3ExprCode(pParse, pRowidExpr);
      sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
    }

    /* Compute new data for this record.  
    */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp(v, OP_Null, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( j<0 ){
        sqlite3VdbeAddOp(v, OP_Column, iCur, i);
        sqlite3ColumnDefault(v, pTab, i);
      }else{
        sqlite3ExprCode(pParse, pChanges->a[j].pExpr);
      }
    }

    /* Do constraint checks
................................................................................
    /* Delete the old indices for the current record.
    */
    sqlite3GenerateRowIndexDelete(v, pTab, iCur, aIdxUsed);

    /* If changing the record number, delete the old record.
    */
    if( chngRowid ){
      sqlite3VdbeAddOp(v, OP_Delete, iCur, 0);
    }

    /* Create the new index entries and the new record.
    */
    sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, -1, 0);
  }

  /* Increment the row counter 
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqlite3VdbeAddOp(v, OP_MemIncr, 1, memCnt);
  }

  /* If there are triggers, close all the cursors after each iteration
  ** through the loop.  The fire the after triggers.
  */
  if( triggers_exist ){
    sqlite3VdbeAddOp(v, OP_Goto, 0, iBeginAfterTrigger);
    sqlite3VdbeJumpHere(v, iEndAfterTrigger);
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
  sqlite3VdbeJumpHere(v, addr);

  /* Close all tables */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    if( openAll || aIdxUsed[i] ){
      sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
    }
  }
  sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
  if( triggers_exist ){
    sqlite3VdbeAddOp(v, OP_Close, newIdx, 0);
    sqlite3VdbeAddOp(v, OP_Close, oldIdx, 0);
  }

  /*
  ** Return the number of rows that were changed. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){
    sqlite3VdbeAddOp(v, OP_ResultRow, memCnt, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", P3_STATIC);
  }

update_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3_free(apIdx);
  sqlite3_free(aXRef);
  sqlite3SrcListDelete(pTabList);
................................................................................
  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
  
  /* Create the ephemeral table into which the update results will
  ** be stored.
  */
  assert( v );
  ephemTab = pParse->nTab++;
  sqlite3VdbeAddOp(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));

  /* fill the ephemeral table 
  */
  dest.iParm = ephemTab;
  sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);

  /*
  ** Generate code to scan the ephemeral table and call VDelete and
  ** VInsert
  */
  sqlite3VdbeAddOp(v, OP_Rewind, ephemTab, 0);
  addr = sqlite3VdbeCurrentAddr(v);
  sqlite3VdbeAddOp(v, OP_Column,  ephemTab, 0);
  if( pRowid ){
    sqlite3VdbeAddOp(v, OP_Column, ephemTab, 1);
  }else{
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
  }
  for(i=0; i<pTab->nCol; i++){
    sqlite3VdbeAddOp(v, OP_Column, ephemTab, i+1+(pRowid!=0));
  }
  pParse->pVirtualLock = pTab;
  sqlite3VdbeOp3(v, OP_VUpdate, 0, pTab->nCol+2, 
                     (const char*)pTab->pVtab, P3_VTAB);
  sqlite3VdbeAddOp(v, OP_Next, ephemTab, addr);
  sqlite3VdbeJumpHere(v, addr-1);
  sqlite3VdbeAddOp(v, OP_Close, ephemTab, 0);

  /* Cleanup */
  sqlite3SelectDelete(pSelect);  
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.149 2008/01/03 00:01:25 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */
................................................................................
  int *aXRef,          /* Mapping from columns of pTab to entries in pChanges */
  Expr *pWhere         /* WHERE clause of the UPDATE statement */
);
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P4 parameter of the 
** OP_Column to the default value, if any.
**
** The default value of a column is specified by a DEFAULT clause in the 
** column definition. This was either supplied by the user when the table
** was created, or added later to the table definition by an ALTER TABLE
** command. If the latter, then the row-records in the table btree on disk
** may not contain a value for the column and the default value, taken
** from the P4 parameter of the OP_Column instruction, is returned instead.
** If the former, then all row-records are guaranteed to include a value
** for the column and the P4 value is not required.
**
** Column definitions created by an ALTER TABLE command may only have 
** literal default values specified: a number, null or a string. (If a more
** complicated default expression value was provided, it is evaluated 
** when the ALTER TABLE is executed and one of the literal values written
** into the sqlite_master table.)
**
** Therefore, the P4 parameter is only required if the default value for
** the column is a literal number, string or null. The sqlite3ValueFromExpr()
** function is capable of transforming these types of expressions into
** sqlite3_value objects.
*/
void sqlite3ColumnDefault(Vdbe *v, Table *pTab, int i){
  if( pTab && !pTab->pSelect ){
    sqlite3_value *pValue;
................................................................................
    u8 enc = ENC(sqlite3VdbeDb(v));
    Column *pCol = &pTab->aCol[i];
    VdbeComment((v, "%s.%s", pTab->zName, pCol->zName));
    assert( i<pTab->nCol );
    sqlite3ValueFromExpr(sqlite3VdbeDb(v), pCol->pDflt, enc, 
                         pCol->affinity, &pValue);
    if( pValue ){
      sqlite3VdbeAddOp2(v, OP_DfltValue, 0, 0);
      sqlite3VdbeChangeP4(v, -1, (const char *)pValue, P4_MEM);
    }
  }
}

/*
** Process an UPDATE statement.
**
................................................................................
  /* Generate the code for triggers.
  */
  if( triggers_exist ){
    int iGoto;

    /* Create pseudo-tables for NEW and OLD
    */
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, oldIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, oldIdx, pTab->nCol);
    sqlite3VdbeAddOp2(v, OP_OpenPseudo, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_SetNumColumns, newIdx, pTab->nCol);

    iGoto = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    addr = sqlite3VdbeMakeLabel(v);
    iBeginBeforeTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab,
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndBeforeTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    iBeginAfterTrigger = sqlite3VdbeCurrentAddr(v);
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, 
          newIdx, oldIdx, onError, addr, &old_col_mask, &new_col_mask) ){
      goto update_cleanup;
    }
    iEndAfterTrigger = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, iGoto);
  }

  /* If we are trying to update a view, realize that view into
  ** a ephemeral table.
  */
  if( isView ){
................................................................................
  /* Begin the database scan
  */
  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
  if( pWInfo==0 ) goto update_cleanup;

  /* Remember the rowid of every item to be updated.
  */
  sqlite3VdbeAddOp2(v, IsVirtual(pTab) ? OP_VRowid : OP_Rowid, iCur, 0);
  sqlite3VdbeAddOp2(v, OP_FifoWrite, 0, 0);

  /* End the database scan loop.
  */
  sqlite3WhereEnd(pWInfo);

  /* Initialize the count of updated rows
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack ){
    memCnt = pParse->nMem++;
    sqlite3VdbeAddOp2(v, OP_MemInt, 0, memCnt);
  }

  if( !isView && !IsVirtual(pTab) ){
    /* 
    ** Open every index that needs updating.  Note that if any
    ** index could potentially invoke a REPLACE conflict resolution 
    ** action, then we need to open all indices because we might need
................................................................................
          break;
        }
      }
    }
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] ){
        KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
        sqlite3VdbeAddOp2(v, OP_Integer, iDb, 0);
        sqlite3VdbeAddOp4(v, OP_OpenWrite, iCur+i+1, pIdx->tnum, 0,
                       (char*)pKey, P4_KEYINFO_HANDOFF);
        assert( pParse->nTab>iCur+i+1 );
      }
    }

  }
  
  /* Jump back to this point if a trigger encounters an IGNORE constraint. */
  if( triggers_exist ){
    sqlite3VdbeResolveLabel(v, addr);
  }

  /* Top of the update loop */
  addr = sqlite3VdbeAddOp2(v, OP_FifoRead, 0, 0);
  sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);
  sqlite3VdbeAddOp2(v, OP_MemStore, mem1, 0);

  if( triggers_exist ){
    /* Make cursor iCur point to the record that is being updated.
    */
    sqlite3VdbeAddOp2(v, OP_NotExists, iCur, addr);

    /* Generate the OLD table
    */
    sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
    if( !old_col_mask ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
    }else{
      sqlite3VdbeAddOp2(v, OP_RowData, iCur, 0);
    }
    sqlite3VdbeAddOp2(v, OP_Insert, oldIdx, 0);

    /* Generate the NEW table
    */
    if( chngRowid ){
      sqlite3ExprCodeAndCache(pParse, pRowidExpr);
    }else{
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( new_col_mask&((u32)1<<i) || new_col_mask==0xffffffff ){
        if( j<0 ){
          sqlite3VdbeAddOp2(v, OP_Column, iCur, i);
          sqlite3ColumnDefault(v, pTab, i);
        }else{
          sqlite3ExprCodeAndCache(pParse, pChanges->a[j].pExpr);
        }
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
      }
    }
    sqlite3VdbeAddOp2(v, OP_MakeRecord, pTab->nCol, 0);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
    }
    if( pParse->nErr ) goto update_cleanup;
    sqlite3VdbeAddOp2(v, OP_Insert, newIdx, 0);

    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginBeforeTrigger);
    sqlite3VdbeJumpHere(v, iEndBeforeTrigger);

    if( !isView ){
      sqlite3VdbeAddOp2(v, OP_MemLoad, mem1, 0);
    }
  }

  if( !isView && !IsVirtual(pTab) ){

    /* Loop over every record that needs updating.  We have to load
    ** the old data for each record to be updated because some columns
    ** might not change and we will need to copy the old value.
    ** Also, the old data is needed to delete the old index entries.
    ** So make the cursor point at the old record.
    */
    sqlite3VdbeAddOp2(v, OP_NotExists, iCur, addr);
    sqlite3VdbeAddOp2(v, OP_MemLoad, mem1, 0);

    /* If the record number will change, push the record number as it
    ** will be after the update. (The old record number is currently
    ** on top of the stack.)
    */
    if( chngRowid ){
      sqlite3ExprCode(pParse, pRowidExpr);
      sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    }

    /* Compute new data for this record.  
    */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
        continue;
      }
      j = aXRef[i];
      if( j<0 ){
        sqlite3VdbeAddOp2(v, OP_Column, iCur, i);
        sqlite3ColumnDefault(v, pTab, i);
      }else{
        sqlite3ExprCode(pParse, pChanges->a[j].pExpr);
      }
    }

    /* Do constraint checks
................................................................................
    /* Delete the old indices for the current record.
    */
    sqlite3GenerateRowIndexDelete(v, pTab, iCur, aIdxUsed);

    /* If changing the record number, delete the old record.
    */
    if( chngRowid ){
      sqlite3VdbeAddOp2(v, OP_Delete, iCur, 0);
    }

    /* Create the new index entries and the new record.
    */
    sqlite3CompleteInsertion(pParse, pTab, iCur, aIdxUsed, chngRowid, 1, -1, 0);
  }

  /* Increment the row counter 
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack){
    sqlite3VdbeAddOp2(v, OP_MemIncr, 1, memCnt);
  }

  /* If there are triggers, close all the cursors after each iteration
  ** through the loop.  The fire the after triggers.
  */
  if( triggers_exist ){
    sqlite3VdbeAddOp2(v, OP_Goto, 0, iBeginAfterTrigger);
    sqlite3VdbeJumpHere(v, iEndAfterTrigger);
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addr);
  sqlite3VdbeJumpHere(v, addr);

  /* Close all tables */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    if( openAll || aIdxUsed[i] ){
      sqlite3VdbeAddOp2(v, OP_Close, iCur+i+1, 0);
    }
  }
  sqlite3VdbeAddOp2(v, OP_Close, iCur, 0);
  if( triggers_exist ){
    sqlite3VdbeAddOp2(v, OP_Close, newIdx, 0);
    sqlite3VdbeAddOp2(v, OP_Close, oldIdx, 0);
  }

  /*
  ** Return the number of rows that were changed. If this routine is 
  ** generating code because of a call to sqlite3NestedParse(), do not
  ** invoke the callback function.
  */
  if( db->flags & SQLITE_CountRows && !pParse->trigStack && pParse->nested==0 ){
    sqlite3VdbeAddOp2(v, OP_ResultRow, memCnt, 1);
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", P4_STATIC);
  }

update_cleanup:
  sqlite3AuthContextPop(&sContext);
  sqlite3_free(apIdx);
  sqlite3_free(aXRef);
  sqlite3SrcListDelete(pTabList);
................................................................................
  pSelect = sqlite3SelectNew(pParse, pEList, pSrc, pWhere, 0, 0, 0, 0, 0, 0);
  
  /* Create the ephemeral table into which the update results will
  ** be stored.
  */
  assert( v );
  ephemTab = pParse->nTab++;
  sqlite3VdbeAddOp2(v, OP_OpenEphemeral, ephemTab, pTab->nCol+1+(pRowid!=0));

  /* fill the ephemeral table 
  */
  dest.iParm = ephemTab;
  sqlite3Select(pParse, pSelect, &dest, 0, 0, 0, 0);

  /*
  ** Generate code to scan the ephemeral table and call VDelete and
  ** VInsert
  */
  sqlite3VdbeAddOp2(v, OP_Rewind, ephemTab, 0);
  addr = sqlite3VdbeCurrentAddr(v);
  sqlite3VdbeAddOp2(v, OP_Column,  ephemTab, 0);
  if( pRowid ){
    sqlite3VdbeAddOp2(v, OP_Column, ephemTab, 1);
  }else{
    sqlite3VdbeAddOp2(v, OP_Dup, 0, 0);
  }
  for(i=0; i<pTab->nCol; i++){
    sqlite3VdbeAddOp2(v, OP_Column, ephemTab, i+1+(pRowid!=0));
  }
  pParse->pVirtualLock = pTab;
  sqlite3VdbeAddOp4(v, OP_VUpdate, 0, pTab->nCol+2, 0,
                     (const char*)pTab->pVtab, P4_VTAB);
  sqlite3VdbeAddOp2(v, OP_Next, ephemTab, addr);
  sqlite3VdbeJumpHere(v, addr-1);
  sqlite3VdbeAddOp2(v, OP_Close, ephemTab, 0);

  /* Cleanup */
  sqlite3SelectDelete(pSelect);  
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.75 2007/12/05 01:38:24 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/*
** Execute zSql on database db. Return an error code.
................................................................................
** gdbm_reorganize() on all the database tables.  But beginning
** with 2.0.0, SQLite no longer uses GDBM so this command has
** become a no-op.
*/
void sqlite3Vacuum(Parse *pParse){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp(v, OP_Vacuum, 0, 0);
  }
  return;
}

/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.76 2008/01/03 00:01:25 drh Exp $
*/
#include "sqliteInt.h"
#include "vdbeInt.h"

#if !defined(SQLITE_OMIT_VACUUM) && !defined(SQLITE_OMIT_ATTACH)
/*
** Execute zSql on database db. Return an error code.
................................................................................
** gdbm_reorganize() on all the database tables.  But beginning
** with 2.0.0, SQLite no longer uses GDBM so this command has
** become a no-op.
*/
void sqlite3Vacuum(Parse *pParse){
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
  }
  return;
}

/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/

** In the external interface, an "sqlite3_stmt*" is an opaque pointer
** to a VDBE.
**
** The SQL parser generates a program which is then executed by
** the VDBE to do the work of the SQL statement.  VDBE programs are 
** similar in form to assembly language.  The program consists of
** a linear sequence of operations.  Each operation has an opcode 
** and 3 operands.  Operands P1 and P2 are integers.  Operand P3 
** is a null-terminated string.   The P2 operand must be non-negative.
** Opcodes will typically ignore one or more operands.  Many opcodes
** ignore all three operands.
**
** Computation results are stored on a stack.  Each entry on the
** stack is either an integer, a null-terminated string, a floating point
** number, or the SQL "NULL" value.  An inplicit conversion from one
................................................................................
**
** 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 1.663 2008/01/02 14:28:13 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
    p->popStack = 0;
  }
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);
#ifdef SQLITE_DEBUG
  if( (p->db->flags & SQLITE_VdbeListing)!=0
    || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS)
  ){
    int i;
    printf("VDBE Program Listing:\n");
    sqlite3VdbePrintSql(p);
    for(i=0; i<p->nOp; i++){
      sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
    }
................................................................................
case OP_Return: {           /* no-push */
  assert( p->returnDepth>0 );
  p->returnDepth--;
  pc = p->returnStack[p->returnDepth] - 1;
  break;
}

/* Opcode:  Halt P1 P2 P3
**
** Exit immediately.  All open cursors, Fifos, etc are closed
** automatically.
**
** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
** or sqlite3_finalize().  For a normal halt, this should be SQLITE_OK (0).
** For errors, it can be some other value.  If P1!=0 then P2 will determine
** whether or not to rollback the current transaction.  Do not rollback
** if P2==OE_Fail. Do the rollback if P2==OE_Rollback.  If P2==OE_Abort,
** then back out all changes that have occurred during this execution of the
** VDBE, but do not rollback the transaction. 
**
** If P3 is not null then it is an error message string.
**
** There is an implied "Halt 0 0 0" instruction inserted at the very end of
** every program.  So a jump past the last instruction of the program
** is the same as executing Halt.
*/
case OP_Halt: {            /* no-push */
  p->pTos = pTos;
  p->rc = pOp->p1;
  p->pc = pc;
  p->errorAction = pOp->p2;
  if( pOp->p3.p ){
    sqlite3SetString(&p->zErrMsg, pOp->p3.p, (char*)0);
  }
  rc = sqlite3VdbeHalt(p);
  assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
  if( rc==SQLITE_BUSY ){
    p->rc = rc = SQLITE_BUSY;
  }else{
    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
................................................................................
case OP_Integer: {
  pTos++;
  pTos->flags = MEM_Int;
  pTos->u.i = pOp->p1;
  break;
}

/* Opcode: Int64 * * P3
**
** P3 is a pointer to a 64-bit integer value.
** Push  that value onto  the stack.
*/
case OP_Int64: {
  pTos++;
  assert( pOp->p3.p!=0 );
  pTos->flags = MEM_Int;
  memcpy(&pTos->u.i, pOp->p3.p, 8);
  break;
}

/* Opcode: Real * * P3
**
** P3 is a pointer to a 64-bit floating point value.  Push that value
** onto the stack.
*/
case OP_Real: {            /* same as TK_FLOAT, */
  pTos++;
  pTos->flags = MEM_Real;
  memcpy(&pTos->r, pOp->p3.p, 8);
  break;
}

/* Opcode: String8 * * P3
**
** P3 points to a nul terminated UTF-8 string. This opcode is transformed 
** into an OP_String before it is executed for the first time.
*/
case OP_String8: {         /* same as TK_STRING */
  assert( pOp->p3.p!=0 );
  pOp->opcode = OP_String;
  pOp->p1 = strlen(pOp->p3.p);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    pTos++;
    sqlite3VdbeMemSetStr(pTos, pOp->p3.p, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pTos, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pTos) ) goto no_mem;
    pTos->flags &= ~(MEM_Dyn);
    pTos->flags |= MEM_Static;
    if( pOp->p3type==P3_DYNAMIC ){
      sqlite3_free(pOp->p3.p);
    }
    pOp->p3type = P3_DYNAMIC;
    pOp->p3.p = pTos->z;
    pOp->p1 = pTos->n;
    if( pOp->p1>SQLITE_MAX_LENGTH ){
      goto too_big;
    }
    break;
  }
#endif
  if( pOp->p1>SQLITE_MAX_LENGTH ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}
  
/* Opcode: String P1 * P3
**
** The string value P3 of length P1 (bytes) is pushed onto the stack.
*/
case OP_String: {
  pTos++;
  assert( pOp->p3.p!=0 );
  pTos->flags = MEM_Str|MEM_Static|MEM_Term;
  pTos->z = pOp->p3.p;
  pTos->n = pOp->p1;
  pTos->enc = encoding;
  break;
}

/* Opcode: Null * * *
**
................................................................................
  pTos->flags = MEM_Null;
  pTos->n = 0;
  break;
}


#ifndef SQLITE_OMIT_BLOB_LITERAL
/* Opcode: HexBlob * * P3
**
** P3 is an UTF-8 SQL hex encoding of a blob. The blob is pushed onto the
** vdbe stack.
**
** The first time this instruction executes, in transforms itself into a
** 'Blob' opcode with a binary blob as P3.
*/
case OP_HexBlob: {            /* same as TK_BLOB */
  pOp->opcode = OP_Blob;
  pOp->p1 = strlen(pOp->p3.p)/2;
  if( pOp->p1>SQLITE_MAX_LENGTH ){
    goto too_big;
  }
  if( pOp->p1 ){
    char *zBlob = sqlite3HexToBlob(db, pOp->p3.p);
    if( !zBlob ) goto no_mem;
    if( pOp->p3type==P3_DYNAMIC ){
      sqlite3_free(pOp->p3.p);
    }
    pOp->p3.p = zBlob;
    pOp->p3type = P3_DYNAMIC;
  }else{
    if( pOp->p3type==P3_DYNAMIC ){
      sqlite3_free(pOp->p3.p);
    }
    pOp->p3type = P3_STATIC;
    pOp->p3.p = "";
  }

  /* Fall through to the next case, OP_Blob. */
}

/* Opcode: Blob P1 * P3
**
** P3 points to a blob of data P1 bytes long. Push this
** value onto the stack. This instruction is not coded directly
** by the compiler. Instead, the compiler layer specifies
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P3. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {
  pTos++;
  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
  sqlite3VdbeMemSetStr(pTos, pOp->p3.p, pOp->p1, 0, 0);
  pTos->enc = encoding;
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 * *
**
................................................................................
  Release(pTos);
  pTos--;
  Release(pTos);
  pTos->flags = MEM_Null;
  break;
}

/* Opcode: CollSeq * * P3
**
** P3 is a pointer to a CollSeq struct. If the next call to a user function
** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
** be returned. This is used by the built-in min(), max() and nullif()
** functions.
**
** The interface used by the implementation of the aforementioned functions
** to retrieve the collation sequence set by this opcode is not available
** publicly, only to user functions defined in func.c.
*/
case OP_CollSeq: {             /* no-push */
  assert( pOp->p3type==P3_COLLSEQ );
  break;
}

/* Opcode: Function P1 P2 P3
**
** Invoke a user function (P3 is a pointer to a Function structure that
** defines the function) with P2 arguments taken from the stack.  Pop all
** arguments from the stack and push back the result.
**
** P1 is a 32-bit bitmask indicating whether or not each argument to the 
** function was determined to be constant at compile time. If the first
** argument was constant then bit 0 of P1 is set. This is used to determine
** whether meta data associated with a user function argument using the
................................................................................

  pArg = &pTos[1-n];
  for(i=0; i<n; i++, pArg++){
    apVal[i] = pArg;
    storeTypeInfo(pArg, encoding);
  }

  assert( pOp->p3type==P3_FUNCDEF || pOp->p3type==P3_VDBEFUNC );
  if( pOp->p3type==P3_FUNCDEF ){
    ctx.pFunc = (FuncDef*)pOp->p3.p;
    ctx.pVdbeFunc = 0;
  }else{
    ctx.pVdbeFunc = (VdbeFunc*)pOp->p3.p;
    ctx.pFunc = ctx.pVdbeFunc->pFunc;
  }

  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3.p;
  }
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  (*ctx.pFunc->xFunc)(&ctx, n, apVal);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( db->mallocFailed ){
    /* Even though a malloc() has failed, the implementation of the
    ** user function may have called an sqlite3_result_XXX() function
................................................................................
  popStack(&pTos, n);

  /* If any auxilary data functions have been called by this user function,
  ** immediately call the destructor for any non-static values.
  */
  if( ctx.pVdbeFunc ){
    sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
    pOp->p3.p = (char *)ctx.pVdbeFunc;
    pOp->p3type = P3_VDBEFUNC;
  }

  /* If the function returned an error, throw an exception */
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }
................................................................................
  if( (pTos->flags & MEM_Null)==0 ){
    sqlite3VdbeMemRealify(pTos);
  }
  break;
}
#endif /* SQLITE_OMIT_CAST */

/* Opcode: Eq P1 P2 P3
**
** Pop the top two elements from the stack.  If they are equal, then
** jump to instruction P2.  Otherwise, continue to the next instruction.
**
** If the 0x100 bit of P1 is true and either operand is NULL then take the
** jump.  If the 0x100 bit of P1 is clear then fall thru if either operand
** is NULL.
................................................................................
** both values are numeric, then a numeric comparison is used. If the
** two values are of different types, then they are inequal.
**
** If P2 is zero, do not jump.  Instead, push an integer 1 onto the
** stack if the jump would have been taken, or a 0 if not.  Push a
** NULL if either operand was NULL.
**
** If P3 is not NULL it is a pointer to a collating sequence (a CollSeq
** structure) that defines how to compare text.
*/
/* Opcode: Ne P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the operands from the stack are not equal.  See the Eq opcode for
** additional information.
*/
/* Opcode: Lt P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Le P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
/* Opcode: Gt P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Ge P1 P2 P3
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, no-push */
case OP_Ne:               /* same as TK_NE, no-push */
................................................................................

  affinity = pOp->p1 & 0xFF;
  if( affinity ){
    applyAffinity(pNos, affinity, encoding);
    applyAffinity(pTos, affinity, encoding);
  }

  assert( pOp->p3type==P3_COLLSEQ || pOp->p3.p==0 );
  ExpandBlob(pNos);
  ExpandBlob(pTos);
  res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p3.p);
  switch( pOp->opcode ){
    case OP_Eq:    res = res==0;     break;
    case OP_Ne:    res = res!=0;     break;
    case OP_Lt:    res = res<0;      break;
    case OP_Le:    res = res<=0;     break;
    case OP_Gt:    res = res>0;      break;
    default:       res = res>=0;     break;
................................................................................
  assert( (pOp->p1)<p->nCursor );
  assert( p->apCsr[pOp->p1]!=0 );
  pC = p->apCsr[pOp->p1];
  pC->nField = pOp->p2;
  break;
}

/* Opcode: Column P1 P2 P3
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
** information about the format of the data.)  Extract the P2-th column
** from this record.  If there are less that (P2+1) 
** values in the record, extract a NULL.
**
** The value extracted is pushed onto the stack.  Or if P3 is an integer
** register number, then the value is written into that register.
**
** If the KeyAsData opcode has previously executed on this cursor, then the
** field might be extracted from the key rather than the data.
**
** If the column contains fewer than P2 fields, then extract a NULL.  Or
** if the next instruction is OP_DfltValue then the P3 argument to the
** OP_DfltValue instruction will be a P3_MEM.  Use the P3 argument of
** the OP_DfltValue instruction as the extracted value instead of NULL.
** The OP_DfltValue P3 value will be a default value for a column 
** that has been added using the ALTER TABLE ADD COLUMN command.
*/
case OP_Column: {
  u32 payloadSize;   /* Number of bytes in the record */
  int p1 = pOp->p1;  /* P1 value of the opcode */
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;    /* The VDBE cursor */
................................................................................
  int i;             /* Loop counter */
  char *zData;       /* Part of the record being decoded */
  Mem *pDest;        /* Where to write the extracted value */
  Mem sMem;          /* For storing the record being decoded */

  sMem.flags = 0;
  assert( p1<p->nCursor );
  if( pOp->p3type==P3_INT32 ){
    assert( pOp->p3.i>=0 && pOp->p3.i<p->nMem );
    pDest = &p->aMem[pOp->p3.i];
  }else{
    pDest = ++pTos;
  }
  sqlite3VdbeMemSetNull(pDest);

  /* This block sets the variable payloadSize to be the total number of
  ** bytes in the record.
................................................................................
      goto op_column_out;
    }
  }

  /* Get the column information. If aOffset[p2] is non-zero, then 
  ** deserialize the value from the record. If aOffset[p2] is zero,
  ** then there are not enough fields in the record to satisfy the
  ** request.  In this case, set the value NULL or to P3 if P3 is
  ** a pointer to a Mem object.
  */
  if( aOffset[p2] ){
    assert( rc==SQLITE_OK );
    if( zRec ){
      zData = &zRec[aOffset[p2]];
    }else{
................................................................................
      }
      zData = sMem.z;
    }
    sqlite3VdbeSerialGet((u8*)zData, aType[p2], pDest);
    pDest->enc = encoding;
  }else{
    if( pOp[1].opcode==OP_DfltValue ){
      assert( pOp[1].p3type==P3_MEM );
      sqlite3VdbeMemShallowCopy(pDest, (Mem *)(pOp[1].p3.p), MEM_Static);
    }else{
      assert( pDest->flags==MEM_Null );
    }
  }

  /* If we dynamically allocated space to hold the data (in the
  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
................................................................................
op_column_out:
  if( pOp[1].opcode==OP_DfltValue ){
    pc++;
  }
  break;
}

/* Opcode: DfltValue * * P3
**
** This instruction always follows an OP_Column.  This instruction
** does nothing by itself.  It is just a place holder for the default
** value for the previous OP_Column instruction.
*/
case OP_DfltValue: {       /* no-push */
  assert( 0 );
}

/* Opcode: MakeRecord P1 P2 P3
**
** Convert the top abs(P1) entries of the stack into a single entry
** suitable for use as a data record in a database table or as a key
** in an index.  The details of the format are irrelavant as long as
** the OP_Column opcode can decode the record later and as long as the
** sqlite3VdbeRecordCompare function will correctly compare two encoded
** records.  Refer to source code comments for the details of the record
................................................................................
** The original stack entries are popped from the stack if P1>0 but
** remain on the stack if P1<0.
**
** If P2 is not zero and one or more of the entries are NULL, then jump
** to the address given by P2.  This feature can be used to skip a
** uniqueness test on indices.
**
** P3 may be a string that is P1 characters long.  The nth character of the
** string indicates the column affinity that should be used for the nth
** field of the index key (i.e. the first character of P3 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P3 is NULL then all index fields have the affinity NONE.
**
** See also OP_MakeIdxRec
*/
/* Opcode: MakeIdxRec P1 P2 P3
**
** This opcode works just OP_MakeRecord except that it reads an extra
** integer from the stack (thus reading a total of abs(P1+1) entries)
** and appends that extra integer to the end of the record as a varint.
** This results in an index key.
*/
/*
** Opcode: RegMakeRec P1 P2 P3
**
** Works like OP_MakeRecord except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
/*
** Opcode: RegMakeIRec P1 P2 P3
**
** Works like OP_MakeIdxRec except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
case OP_RegMakeRec:
................................................................................
    nField = -pOp->p1;
  }else{
    leaveOnStack = 0;
    nField = pOp->p1;
  }
  jumpIfNull = pOp->p2;
  addRowid = pOp->opcode==OP_MakeIdxRec || pOp->opcode==OP_RegMakeIRec;
  zAffinity = pOp->p3.p;

  if( pOp->opcode==OP_RegMakeRec || pOp->opcode==OP_RegMakeIRec ){
    Mem *pCount;
    assert( nField>=0 && nField<p->nMem );
    pCount = &p->aMem[nField];
    assert( pCount->flags & MEM_Int );
    assert( pCount->u.i>=0 && pCount->u.i+nField<p->nMem );
................................................................................

    sqlite3ExpirePreparedStatements(db);
    rc = SQLITE_SCHEMA;
  }
  break;
}

/* Opcode: OpenRead P1 P2 P3
**
** Open a read-only cursor for the database table whose root page is
** P2 in a database file.  The database file is determined by an 
** integer from the top of the stack.  0 means the main database and
** 1 means the database used for temporary tables.  Give the new 
** cursor an identifier of P1.  The P1 values need not be contiguous
** but all P1 values should be small integers.  It is an error for
................................................................................
** then a read lock is acquired as part of this instruction.  A read
** lock allows other processes to read the database but prohibits
** any other process from modifying the database.  The read lock is
** released when all cursors are closed.  If this instruction attempts
** to get a read lock but fails, the script terminates with an
** SQLITE_BUSY error code.
**
** The P3 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices.  P3 is NULL for cursors
** that are not pointing to indices.
**
** See also OpenWrite.
*/
/* Opcode: OpenWrite P1 P2 P3
**
** Open a read/write cursor named P1 on the table or index whose root
** page is P2.  If P2==0 then take the root page number from the stack.
**
** The P3 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices.  P3 is NULL for cursors
** that are not pointing to indices.
**
** This instruction works just like OpenRead except that it opens the cursor
** in read/write mode.  For a given table, there can be one or more read-only
** cursors or a single read/write cursor but not both.
**
** See also OpenRead.
................................................................................
  pCur = allocateCursor(p, i, iDb);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  if( pX==0 ) break;
  /* We always provide a key comparison function.  If the table being
  ** opened is of type INTKEY, the comparision function will be ignored. */
  rc = sqlite3BtreeCursor(pX, p2, wrFlag,
           sqlite3VdbeRecordCompare, pOp->p3.p,
           &pCur->pCursor);
  if( pOp->p3type==P3_KEYINFO ){
    pCur->pKeyInfo = (KeyInfo*)pOp->p3.p;
    pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
    pCur->pKeyInfo->enc = ENC(p->db);
  }else{
    pCur->pKeyInfo = 0;
    pCur->pIncrKey = &pCur->bogusIncrKey;
  }
  switch( rc ){
................................................................................
      */
      if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }
      pCur->isTable = (flags & BTREE_INTKEY)!=0;
      pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
      /* If P3==0 it means we are expected to open a table.  If P3!=0 then
      ** we expect to be opening an index.  If this is not what happened,
      ** then the database is corrupt
      */
      if( (pCur->isTable && pOp->p3type==P3_KEYINFO)
       || (pCur->isIndex && pOp->p3type!=P3_KEYINFO) ){
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }
      break;
    }
    case SQLITE_EMPTY: {
      pCur->isTable = pOp->p3type!=P3_KEYINFO;
      pCur->isIndex = !pCur->isTable;
      rc = SQLITE_OK;
      break;
    }
    default: {
      goto abort_due_to_error;
    }
  }
  break;
}

/* Opcode: OpenEphemeral P1 P2 P3
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 
** the main database is read-only.  The transient or virtual
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the virtual table.
** The cursor points to a BTree table if P3==0 and to a BTree index
** if P3 is not 0.  If P3 is not NULL, it points to a KeyInfo structure
** that defines the format of keys in the index.
**
** This opcode was once called OpenTemp.  But that created
** confusion because the term "temp table", might refer either
** to a TEMP table at the SQL level, or to a table opened by
** this opcode.  Then this opcode was call OpenVirtual.  But
** that created confusion with the whole virtual-table idea.
................................................................................
  }
  if( rc==SQLITE_OK ){
    /* If a transient index is required, create it by calling
    ** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
    ** opening it. If a transient table is required, just use the
    ** automatically created table with root-page 1 (an INTKEY table).
    */
    if( pOp->p3.p ){
      int pgno;
      assert( pOp->p3type==P3_KEYINFO );
      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA); 
      if( rc==SQLITE_OK ){
        assert( pgno==MASTER_ROOT+1 );
        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, sqlite3VdbeRecordCompare,
            pOp->p3.p, &pCx->pCursor);
        pCx->pKeyInfo = (KeyInfo*)pOp->p3.p;
        pCx->pKeyInfo->enc = ENC(p->db);
        pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
      }
      pCx->isTable = 0;
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, 0, &pCx->pCursor);
      pCx->isTable = 1;
................................................................................
  }
  pTos++;
  pTos->u.i = v;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: Insert P1 P2 P3
**
** Write an entry into the table of cursor P1.  A new entry is
** created if it doesn't already exist or the data for an existing
** entry is overwritten.  The data is the value on the top of the
** stack.  The key is the next value down on the stack.  The key must
** be an integer.  The stack is popped twice by this instruction.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P2 is set,
** then rowid is stored for subsequent return by the
** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
**
** Parameter P3 may point to a string containing the table-name, or
** may be NULL. If it is not NULL, then the update-hook 
** (sqlite3.xUpdateCallback) is invoked following a successful insert.
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/
case OP_Insert: {         /* no-push */
................................................................................
    }
    
    pC->rowidIsValid = 0;
    pC->deferredMoveto = 0;
    pC->cacheStatus = CACHE_STALE;

    /* Invoke the update-hook if required. */
    if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p3.p ){
      const char *zDb = db->aDb[pC->iDb].zName;
      const char *zTbl = pOp->p3.p;
      int op = ((pOp->p2 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
      assert( pC->isTable );
      db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
      assert( pC->iDb>=0 );
    }
  }
  popStack(&pTos, 2);

  break;
}

/* Opcode: Delete P1 P2 P3
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op.  Hence it is OK to delete
** a record from within an Next loop.
................................................................................
  assert( pC!=0 );
  if( pC->pCursor!=0 ){
    i64 iKey;

    /* If the update-hook will be invoked, set iKey to the rowid of the
    ** row being deleted.
    */
    if( db->xUpdateCallback && pOp->p3.p ){
      assert( pC->isTable );
      if( pC->rowidIsValid ){
        iKey = pC->lastRowid;
      }else{
        rc = sqlite3BtreeKeySize(pC->pCursor, &iKey);
        if( rc ){
          goto abort_due_to_error;
................................................................................
    rc = sqlite3VdbeCursorMoveto(pC);
    if( rc ) goto abort_due_to_error;
    rc = sqlite3BtreeDelete(pC->pCursor);
    pC->nextRowidValid = 0;
    pC->cacheStatus = CACHE_STALE;

    /* Invoke the update-hook if required. */
    if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p3.p ){
      const char *zDb = db->aDb[pC->iDb].zName;
      const char *zTbl = pOp->p3.p;
      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
      assert( pC->iDb>=0 );
    }
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
................................................................................
**
** The top of the stack might have fewer columns that P1.
**
** If the P1 index entry is greater than the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
*/
/* Opcode: IdxGE P1 P2 P3
**
** The top of the stack is an index entry that omits the ROWID.  Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is greater than or equal to the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P3 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This make the opcode work
** like IdxGT except that if the key from the stack is a prefix of
** the key in the cursor, the result is false whereas it would be
** true with IdxGT.
*/
/* Opcode: IdxLT P1 P2 P3
**
** The top of the stack is an index entry that omits the ROWID.  Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is less than  the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P3 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This makes the opcode work
** like IdxLE.
*/
case OP_IdxLT:          /* no-push */
case OP_IdxGT:          /* no-push */
case OP_IdxGE: {        /* no-push */
................................................................................
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res;
 
    assert( pTos->flags & MEM_Blob );  /* Created using OP_MakeRecord */
    assert( pC->deferredMoveto==0 );
    ExpandBlob(pTos);
    *pC->pIncrKey = pOp->p3.p!=0;
    assert( pOp->p3.p==0 || pOp->opcode!=OP_IdxGT );
    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, (u8*)pTos->z, &res);
    *pC->pIncrKey = 0;
    if( rc!=SQLITE_OK ){
      break;
    }
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
................................................................................
case OP_Clear: {        /* no-push */

  /* For consistency with the way other features of SQLite operate
  ** with a truncate, we will also skip the update callback.
  */
#if 0
  Btree *pBt = db->aDb[pOp->p2].pBt;
  if( db->xUpdateCallback && pOp->p3.p ){
    const char *zDb = db->aDb[pOp->p2].zName;
    const char *zTbl = pOp->p3.p;
    BtCursor *pCur = 0;
    int fin = 0;

    rc = sqlite3BtreeCursor(pBt, pOp->p1, 0, 0, 0, &pCur);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
................................................................................
    pTos->flags = MEM_Int;
  }else{
    pTos->flags = MEM_Null;
  }
  break;
}

/* Opcode: ParseSchema P1 P2 P3
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P3.  P2 is the "force" flag.   Always do
** the parsing if P2 is true.  If P2 is false, then this routine is a
** no-op if the schema is not currently loaded.  In other words, if P2
** is false, the SQLITE_MASTER table is only parsed if the rest of the
** schema is already loaded into the symbol table.
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine.  It is thus a reentrant opcode.
................................................................................
  }
  zMaster = SCHEMA_TABLE(iDb);
  initData.db = db;
  initData.iDb = pOp->p1;
  initData.pzErrMsg = &p->zErrMsg;
  zSql = sqlite3MPrintf(db,
     "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s",
     db->aDb[iDb].zName, zMaster, pOp->p3.p);
  if( zSql==0 ) goto no_mem;
  sqlite3SafetyOff(db);
  assert( db->init.busy==0 );
  db->init.busy = 1;
  assert( !db->mallocFailed );
  rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
  if( rc==SQLITE_ABORT ) rc = initData.rc;
................................................................................
  int iDb = pOp->p1;
  assert( iDb>=0 && iDb<db->nDb );
  rc = sqlite3AnalysisLoad(db, iDb);
  break;  
}
#endif /* !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)  */

/* Opcode: DropTable P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the table named P3 in database P1.  This is called after a table
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTable: {        /* no-push */
  sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p3.p);
  break;
}

/* Opcode: DropIndex P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the index named P3 in database P1.  This is called after an index
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropIndex: {        /* no-push */
  sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p3.p);
  break;
}

/* Opcode: DropTrigger P1 * P3
**
** Remove the internal (in-memory) data structures that describe
** the trigger named P3 in database P1.  This is called after a trigger
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTrigger: {        /* no-push */
  sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p3.p);
  break;
}


#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Opcode: IntegrityCk P1 P2 *
**
................................................................................
case OP_MemMove: {
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  assert( pOp->p2>=0 && pOp->p2<p->nMem );
  rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], &p->aMem[pOp->p2]);
  break;
}

/* Opcode: AggStep P1 P2 P3
**
** Execute the step function for an aggregate.  The
** function has P2 arguments.  P3 is a pointer to the FuncDef
** structure that specifies the function.  Use memory location
** P1 as the accumulator.
**
** The P2 arguments are popped from the stack.
*/
case OP_AggStep: {        /* no-push */
  int n = pOp->p2;
................................................................................
  assert( pRec>=p->aStack );
  apVal = p->apArg;
  assert( apVal || n==0 );
  for(i=0; i<n; i++, pRec++){
    apVal[i] = pRec;
    storeTypeInfo(pRec, encoding);
  }
  ctx.pFunc = (FuncDef*)pOp->p3.p;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  ctx.pMem = pMem = &p->aMem[pOp->p1];
  pMem->n++;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  ctx.pColl = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p3type==P3_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p3.p;
  }
  (ctx.pFunc->xStep)(&ctx, n, apVal);
  popStack(&pTos, n);
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }
  sqlite3VdbeMemRelease(&ctx.s);
  break;
}

/* Opcode: AggFinal P1 P2 P3
**
** Execute the finalizer function for an aggregate.  P1 is
** the memory location that is the accumulator for the aggregate.
**
** P2 is the number of arguments that the step function takes and
** P3 is a pointer to the FuncDef for this function.  The P2
** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P3 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {        /* no-push */
  Mem *pMem;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  pMem = &p->aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(pMem, (FuncDef*)pOp->p3.p);
  if( rc==SQLITE_ERROR ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(pMem), (char*)0);
  }
  if( sqlite3VdbeMemTooBig(pMem) ){
    goto too_big;
  }
  break;
................................................................................
  }else{
    p->expired = 1;
  }
  break;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/* Opcode: TableLock P1 P2 P3
**
** Obtain a lock on a particular table. This instruction is only used when
** the shared-cache feature is enabled. 
**
** If P1 is not negative, then it is the index of the database
** in sqlite3.aDb[] and a read-lock is required. If P1 is negative, a 
** write-lock is required. In this case the index of the database is the 
** absolute value of P1 minus one (iDb = abs(P1) - 1;) and a write-lock is
** required. 
**
** P2 contains the root-page of the table to lock.
**
** P3 contains a pointer to the name of the table being locked. This is only
** used to generate an error message if the lock cannot be obtained.
*/
case OP_TableLock: {        /* no-push */
  int p1 = pOp->p1; 
  u8 isWriteLock = (p1<0);
  if( isWriteLock ){
    p1 = (-1*p1)-1;
  }
  assert( p1>=0 && p1<db->nDb );
  assert( (p->btreeMask & (1<<p1))!=0 );
  rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
  if( rc==SQLITE_LOCKED ){
    const char *z = (const char *)pOp->p3.p;
    sqlite3SetString(&p->zErrMsg, "database table is locked: ", z, (char*)0);
  }
  break;
}
#endif /* SQLITE_OMIT_SHARED_CACHE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VBegin * * P3
**
** P3 a pointer to an sqlite3_vtab structure. Call the xBegin method 
** for that table.
*/
case OP_VBegin: {   /* no-push */
  rc = sqlite3VtabBegin(db, (sqlite3_vtab *)pOp->p3.p);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VCreate P1 * P3
**
** P3 is the name of a virtual table in database P1. Call the xCreate method
** for that table.
*/
case OP_VCreate: {   /* no-push */
  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p3.p, &p->zErrMsg);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VDestroy P1 * P3
**
** P3 is the name of a virtual table in database P1.  Call the xDestroy method
** of that table.
*/
case OP_VDestroy: {   /* no-push */
  p->inVtabMethod = 2;
  rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p3.p);
  p->inVtabMethod = 0;
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VOpen P1 * P3
**
** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {   /* no-push */
  Cursor *pCur = 0;
  sqlite3_vtab_cursor *pVtabCursor = 0;

  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3.p);
  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;

  assert(pVtab && pModule);
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  rc = pModule->xOpen(pVtab, &pVtabCursor);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( SQLITE_OK==rc ){
................................................................................
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VFilter P1 P2 P3
**
** P1 is a cursor opened using VOpen.  P2 is an address to jump to if
** the filtered result set is empty.
**
** P3 is either NULL or a string that was generated by the xBestIndex
** method of the module.  The interpretation of the P3 string is left
** to the module implementation.
**
** This opcode invokes the xFilter method on the virtual table specified
** by P1.  The integer query plan parameter to xFilter is the top of the
** stack.  Next down on the stack is the argc parameter.  Beneath the
** next of stack are argc additional parameters which are passed to
** xFilter as argv. The topmost parameter (i.e. 3rd element popped from
................................................................................
    for(i = 0; i<nArg; i++){
      apArg[i] = &pTos[i+1-2-nArg];
      storeTypeInfo(apArg[i], 0);
    }

    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
    p->inVtabMethod = 1;
    rc = pModule->xFilter(pCur->pVtabCursor, pTos->u.i, pOp->p3.p, nArg, apArg);
    p->inVtabMethod = 0;
    if( rc==SQLITE_OK ){
      res = pModule->xEof(pCur->pVtabCursor);
    }
    if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;

    if( res ){
................................................................................
  }

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VRename * * P3
**
** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xRename method. The value
** on the top of the stack is popped and passed as the zName argument
** to the xRename method.
*/
case OP_VRename: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3.p);
  assert( pVtab->pModule->xRename );

  Stringify(pTos, encoding);

  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  sqlite3VtabLock(pVtab);
  rc = pVtab->pModule->xRename(pVtab, pTos->z);
................................................................................

  popStack(&pTos, 1);
  break;
}
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VUpdate P1 P2 P3
**
** P3 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xUpdate method. P2 values
** are taken from the stack to pass to the xUpdate invocation. The
** value on the top of the stack corresponds to the p2th element 
** of the argv array passed to xUpdate.
**
** The xUpdate method will do a DELETE or an INSERT or both.
** The argv[0] element (which corresponds to the P2-th element down
................................................................................
** a row to delete.
**
** P1 is a boolean flag. If it is set to true and the xUpdate call
** is successful, then the value returned by sqlite3_last_insert_rowid() 
** is set to the value of the rowid for the row just inserted.
*/
case OP_VUpdate: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p3.p);
  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
  int nArg = pOp->p2;
  assert( pOp->p3type==P3_VTAB );
  if( pModule->xUpdate==0 ){
    sqlite3SetString(&p->zErrMsg, "read-only table", 0);
    rc = SQLITE_ERROR;
  }else{
    int i;
    sqlite_int64 rowid;
    Mem **apArg = p->apArg;

** In the external interface, an "sqlite3_stmt*" is an opaque pointer
** to a VDBE.
**
** The SQL parser generates a program which is then executed by
** the VDBE to do the work of the SQL statement.  VDBE programs are 
** similar in form to assembly language.  The program consists of
** a linear sequence of operations.  Each operation has an opcode 
** and 3 operands.  Operands P1 and P2 are integers.  Operand P4 
** is a null-terminated string.   The P2 operand must be non-negative.
** Opcodes will typically ignore one or more operands.  Many opcodes
** ignore all three operands.
**
** Computation results are stored on a stack.  Each entry on the
** stack is either an integer, a null-terminated string, a floating point
** number, or the SQL "NULL" value.  An inplicit conversion from one
................................................................................
**
** 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 1.664 2008/01/03 00:01:25 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
    p->popStack = 0;
  }
  p->pResultSet = 0;
  db->busyHandler.nBusy = 0;
  CHECK_FOR_INTERRUPT;
  sqlite3VdbeIOTraceSql(p);
#ifdef SQLITE_DEBUG
  if( p->pc==0 && ((p->db->flags & SQLITE_VdbeListing)!=0
    || sqlite3OsAccess(db->pVfs, "vdbe_explain", SQLITE_ACCESS_EXISTS))
  ){
    int i;
    printf("VDBE Program Listing:\n");
    sqlite3VdbePrintSql(p);
    for(i=0; i<p->nOp; i++){
      sqlite3VdbePrintOp(stdout, i, &p->aOp[i]);
    }
................................................................................
case OP_Return: {           /* no-push */
  assert( p->returnDepth>0 );
  p->returnDepth--;
  pc = p->returnStack[p->returnDepth] - 1;
  break;
}

/* Opcode:  Halt P1 P2 P4
**
** Exit immediately.  All open cursors, Fifos, etc are closed
** automatically.
**
** P1 is the result code returned by sqlite3_exec(), sqlite3_reset(),
** or sqlite3_finalize().  For a normal halt, this should be SQLITE_OK (0).
** For errors, it can be some other value.  If P1!=0 then P2 will determine
** whether or not to rollback the current transaction.  Do not rollback
** if P2==OE_Fail. Do the rollback if P2==OE_Rollback.  If P2==OE_Abort,
** then back out all changes that have occurred during this execution of the
** VDBE, but do not rollback the transaction. 
**
** If P4 is not null then it is an error message string.
**
** There is an implied "Halt 0 0 0" instruction inserted at the very end of
** every program.  So a jump past the last instruction of the program
** is the same as executing Halt.
*/
case OP_Halt: {            /* no-push */
  p->pTos = pTos;
  p->rc = pOp->p1;
  p->pc = pc;
  p->errorAction = pOp->p2;
  if( pOp->p4.p ){
    sqlite3SetString(&p->zErrMsg, pOp->p4.p, (char*)0);
  }
  rc = sqlite3VdbeHalt(p);
  assert( rc==SQLITE_BUSY || rc==SQLITE_OK );
  if( rc==SQLITE_BUSY ){
    p->rc = rc = SQLITE_BUSY;
  }else{
    rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
................................................................................
case OP_Integer: {
  pTos++;
  pTos->flags = MEM_Int;
  pTos->u.i = pOp->p1;
  break;
}

/* Opcode: Int64 * * P4
**
** P4 is a pointer to a 64-bit integer value.
** Push  that value onto  the stack.
*/
case OP_Int64: {
  pTos++;
  assert( pOp->p4.p!=0 );
  pTos->flags = MEM_Int;
  memcpy(&pTos->u.i, pOp->p4.p, 8);
  break;
}

/* Opcode: Real * * P4
**
** P4 is a pointer to a 64-bit floating point value.  Push that value
** onto the stack.
*/
case OP_Real: {            /* same as TK_FLOAT, */
  pTos++;
  pTos->flags = MEM_Real;
  memcpy(&pTos->r, pOp->p4.p, 8);
  break;
}

/* Opcode: String8 * * P4
**
** P4 points to a nul terminated UTF-8 string. This opcode is transformed 
** into an OP_String before it is executed for the first time.
*/
case OP_String8: {         /* same as TK_STRING */
  assert( pOp->p4.p!=0 );
  pOp->opcode = OP_String;
  pOp->p1 = strlen(pOp->p4.p);

#ifndef SQLITE_OMIT_UTF16
  if( encoding!=SQLITE_UTF8 ){
    pTos++;
    sqlite3VdbeMemSetStr(pTos, pOp->p4.p, -1, SQLITE_UTF8, SQLITE_STATIC);
    if( SQLITE_OK!=sqlite3VdbeChangeEncoding(pTos, encoding) ) goto no_mem;
    if( SQLITE_OK!=sqlite3VdbeMemDynamicify(pTos) ) goto no_mem;
    pTos->flags &= ~(MEM_Dyn);
    pTos->flags |= MEM_Static;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3_free(pOp->p4.p);
    }
    pOp->p4type = P4_DYNAMIC;
    pOp->p4.p = pTos->z;
    pOp->p1 = pTos->n;
    if( pOp->p1>SQLITE_MAX_LENGTH ){
      goto too_big;
    }
    break;
  }
#endif
  if( pOp->p1>SQLITE_MAX_LENGTH ){
    goto too_big;
  }
  /* Fall through to the next case, OP_String */
}
  
/* Opcode: String P1 * P4
**
** The string value P4 of length P1 (bytes) is pushed onto the stack.
*/
case OP_String: {
  pTos++;
  assert( pOp->p4.p!=0 );
  pTos->flags = MEM_Str|MEM_Static|MEM_Term;
  pTos->z = pOp->p4.p;
  pTos->n = pOp->p1;
  pTos->enc = encoding;
  break;
}

/* Opcode: Null * * *
**
................................................................................
  pTos->flags = MEM_Null;
  pTos->n = 0;
  break;
}


#ifndef SQLITE_OMIT_BLOB_LITERAL
/* Opcode: HexBlob * * P4
**
** P4 is an UTF-8 SQL hex encoding of a blob. The blob is pushed onto the
** vdbe stack.
**
** The first time this instruction executes, in transforms itself into a
** 'Blob' opcode with a binary blob as P4.
*/
case OP_HexBlob: {            /* same as TK_BLOB */
  pOp->opcode = OP_Blob;
  pOp->p1 = strlen(pOp->p4.p)/2;
  if( pOp->p1>SQLITE_MAX_LENGTH ){
    goto too_big;
  }
  if( pOp->p1 ){
    char *zBlob = sqlite3HexToBlob(db, pOp->p4.p);
    if( !zBlob ) goto no_mem;
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3_free(pOp->p4.p);
    }
    pOp->p4.p = zBlob;
    pOp->p4type = P4_DYNAMIC;
  }else{
    if( pOp->p4type==P4_DYNAMIC ){
      sqlite3_free(pOp->p4.p);
    }
    pOp->p4type = P4_STATIC;
    pOp->p4.p = "";
  }

  /* Fall through to the next case, OP_Blob. */
}

/* Opcode: Blob P1 * P4
**
** P4 points to a blob of data P1 bytes long. Push this
** value onto the stack. This instruction is not coded directly
** by the compiler. Instead, the compiler layer specifies
** an OP_HexBlob opcode, with the hex string representation of
** the blob as P4. This opcode is transformed to an OP_Blob
** the first time it is executed.
*/
case OP_Blob: {
  pTos++;
  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
  sqlite3VdbeMemSetStr(pTos, pOp->p4.p, pOp->p1, 0, 0);
  pTos->enc = encoding;
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 * *
**
................................................................................
  Release(pTos);
  pTos--;
  Release(pTos);
  pTos->flags = MEM_Null;
  break;
}

/* Opcode: CollSeq * * P4
**
** P4 is a pointer to a CollSeq struct. If the next call to a user function
** or aggregate calls sqlite3GetFuncCollSeq(), this collation sequence will
** be returned. This is used by the built-in min(), max() and nullif()
** functions.
**
** The interface used by the implementation of the aforementioned functions
** to retrieve the collation sequence set by this opcode is not available
** publicly, only to user functions defined in func.c.
*/
case OP_CollSeq: {             /* no-push */
  assert( pOp->p4type==P4_COLLSEQ );
  break;
}

/* Opcode: Function P1 P2 P4
**
** Invoke a user function (P4 is a pointer to a Function structure that
** defines the function) with P2 arguments taken from the stack.  Pop all
** arguments from the stack and push back the result.
**
** P1 is a 32-bit bitmask indicating whether or not each argument to the 
** function was determined to be constant at compile time. If the first
** argument was constant then bit 0 of P1 is set. This is used to determine
** whether meta data associated with a user function argument using the
................................................................................

  pArg = &pTos[1-n];
  for(i=0; i<n; i++, pArg++){
    apVal[i] = pArg;
    storeTypeInfo(pArg, encoding);
  }

  assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
  if( pOp->p4type==P4_FUNCDEF ){
    ctx.pFunc = (FuncDef*)pOp->p4.p;
    ctx.pVdbeFunc = 0;
  }else{
    ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.p;
    ctx.pFunc = ctx.pVdbeFunc->pFunc;
  }

  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p4.p;
  }
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  (*ctx.pFunc->xFunc)(&ctx, n, apVal);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( db->mallocFailed ){
    /* Even though a malloc() has failed, the implementation of the
    ** user function may have called an sqlite3_result_XXX() function
................................................................................
  popStack(&pTos, n);

  /* If any auxilary data functions have been called by this user function,
  ** immediately call the destructor for any non-static values.
  */
  if( ctx.pVdbeFunc ){
    sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
    pOp->p4.p = (char *)ctx.pVdbeFunc;
    pOp->p4type = P4_VDBEFUNC;
  }

  /* If the function returned an error, throw an exception */
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }
................................................................................
  if( (pTos->flags & MEM_Null)==0 ){
    sqlite3VdbeMemRealify(pTos);
  }
  break;
}
#endif /* SQLITE_OMIT_CAST */

/* Opcode: Eq P1 P2 P4
**
** Pop the top two elements from the stack.  If they are equal, then
** jump to instruction P2.  Otherwise, continue to the next instruction.
**
** If the 0x100 bit of P1 is true and either operand is NULL then take the
** jump.  If the 0x100 bit of P1 is clear then fall thru if either operand
** is NULL.
................................................................................
** both values are numeric, then a numeric comparison is used. If the
** two values are of different types, then they are inequal.
**
** If P2 is zero, do not jump.  Instead, push an integer 1 onto the
** stack if the jump would have been taken, or a 0 if not.  Push a
** NULL if either operand was NULL.
**
** If P4 is not NULL it is a pointer to a collating sequence (a CollSeq
** structure) that defines how to compare text.
*/
/* Opcode: Ne P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the operands from the stack are not equal.  See the Eq opcode for
** additional information.
*/
/* Opcode: Lt P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Le P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is less than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
/* Opcode: Gt P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than the top of the stack.
** See the Eq opcode for additional information.
*/
/* Opcode: Ge P1 P2 P4
**
** This works just like the Eq opcode except that the jump is taken if
** the 2nd element down on the stack is greater than or equal to the
** top of the stack.  See the Eq opcode for additional information.
*/
case OP_Eq:               /* same as TK_EQ, no-push */
case OP_Ne:               /* same as TK_NE, no-push */
................................................................................

  affinity = pOp->p1 & 0xFF;
  if( affinity ){
    applyAffinity(pNos, affinity, encoding);
    applyAffinity(pTos, affinity, encoding);
  }

  assert( pOp->p4type==P4_COLLSEQ || pOp->p4.p==0 );
  ExpandBlob(pNos);
  ExpandBlob(pTos);
  res = sqlite3MemCompare(pNos, pTos, (CollSeq*)pOp->p4.p);
  switch( pOp->opcode ){
    case OP_Eq:    res = res==0;     break;
    case OP_Ne:    res = res!=0;     break;
    case OP_Lt:    res = res<0;      break;
    case OP_Le:    res = res<=0;     break;
    case OP_Gt:    res = res>0;      break;
    default:       res = res>=0;     break;
................................................................................
  assert( (pOp->p1)<p->nCursor );
  assert( p->apCsr[pOp->p1]!=0 );
  pC = p->apCsr[pOp->p1];
  pC->nField = pOp->p2;
  break;
}

/* Opcode: Column P1 P2 P3 *
**
** Interpret the data that cursor P1 points to as a structure built using
** the MakeRecord instruction.  (See the MakeRecord opcode for additional
** information about the format of the data.)  Extract the P2-th column
** from this record.  If there are less that (P2+1) 
** values in the record, extract a NULL.
**
** The value extracted is pushed onto the stack.  Or if P3 is a positive
** integer register number, then the value is written into that register.
**
** If the KeyAsData opcode has previously executed on this cursor, then the
** field might be extracted from the key rather than the data.
**
** If the column contains fewer than P2 fields, then extract a NULL.  Or
** if the next instruction is OP_DfltValue then the P4 argument to the
** OP_DfltValue instruction will be a P4_MEM.  Use the P4 argument of
** the OP_DfltValue instruction as the extracted value instead of NULL.
** The OP_DfltValue P4 value will be a default value for a column 
** that has been added using the ALTER TABLE ADD COLUMN command.
*/
case OP_Column: {
  u32 payloadSize;   /* Number of bytes in the record */
  int p1 = pOp->p1;  /* P1 value of the opcode */
  int p2 = pOp->p2;  /* column number to retrieve */
  Cursor *pC = 0;    /* The VDBE cursor */
................................................................................
  int i;             /* Loop counter */
  char *zData;       /* Part of the record being decoded */
  Mem *pDest;        /* Where to write the extracted value */
  Mem sMem;          /* For storing the record being decoded */

  sMem.flags = 0;
  assert( p1<p->nCursor );
  if( pOp->p3>0 ){

    pDest = &p->aMem[pOp->p3];
  }else{
    pDest = ++pTos;
  }
  sqlite3VdbeMemSetNull(pDest);

  /* This block sets the variable payloadSize to be the total number of
  ** bytes in the record.
................................................................................
      goto op_column_out;
    }
  }

  /* Get the column information. If aOffset[p2] is non-zero, then 
  ** deserialize the value from the record. If aOffset[p2] is zero,
  ** then there are not enough fields in the record to satisfy the
  ** request.  In this case, set the value NULL or to P4 if P4 is
  ** a pointer to a Mem object.
  */
  if( aOffset[p2] ){
    assert( rc==SQLITE_OK );
    if( zRec ){
      zData = &zRec[aOffset[p2]];
    }else{
................................................................................
      }
      zData = sMem.z;
    }
    sqlite3VdbeSerialGet((u8*)zData, aType[p2], pDest);
    pDest->enc = encoding;
  }else{
    if( pOp[1].opcode==OP_DfltValue ){
      assert( pOp[1].p4type==P4_MEM );
      sqlite3VdbeMemShallowCopy(pDest, (Mem *)(pOp[1].p4.p), MEM_Static);
    }else{
      assert( pDest->flags==MEM_Null );
    }
  }

  /* If we dynamically allocated space to hold the data (in the
  ** sqlite3VdbeMemFromBtree() call above) then transfer control of that
................................................................................
op_column_out:
  if( pOp[1].opcode==OP_DfltValue ){
    pc++;
  }
  break;
}

/* Opcode: DfltValue * * P4
**
** This instruction always follows an OP_Column.  This instruction
** does nothing by itself.  It is just a place holder for the default
** value for the previous OP_Column instruction.
*/
case OP_DfltValue: {       /* no-push */
  assert( 0 );
}

/* Opcode: MakeRecord P1 P2 P4
**
** Convert the top abs(P1) entries of the stack into a single entry
** suitable for use as a data record in a database table or as a key
** in an index.  The details of the format are irrelavant as long as
** the OP_Column opcode can decode the record later and as long as the
** sqlite3VdbeRecordCompare function will correctly compare two encoded
** records.  Refer to source code comments for the details of the record
................................................................................
** The original stack entries are popped from the stack if P1>0 but
** remain on the stack if P1<0.
**
** If P2 is not zero and one or more of the entries are NULL, then jump
** to the address given by P2.  This feature can be used to skip a
** uniqueness test on indices.
**
** P4 may be a string that is P1 characters long.  The nth character of the
** string indicates the column affinity that should be used for the nth
** field of the index key (i.e. the first character of P4 corresponds to the
** lowest element on the stack).
**
** The mapping from character to affinity is given by the SQLITE_AFF_
** macros defined in sqliteInt.h.
**
** If P4 is NULL then all index fields have the affinity NONE.
**
** See also OP_MakeIdxRec
*/
/* Opcode: MakeIdxRec P1 P2 P4
**
** This opcode works just OP_MakeRecord except that it reads an extra
** integer from the stack (thus reading a total of abs(P1+1) entries)
** and appends that extra integer to the end of the record as a varint.
** This results in an index key.
*/
/*
** Opcode: RegMakeRec P1 P2 P4
**
** Works like OP_MakeRecord except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
/*
** Opcode: RegMakeIRec P1 P2 P4
**
** Works like OP_MakeIdxRec except data is taken from registers
** rather than from the stack.  The P1 register is an integer which
** is the number of register to use in building the new record.
** Data is taken from P1+1, P1+2, ..., P1+mem[P1].
*/
case OP_RegMakeRec:
................................................................................
    nField = -pOp->p1;
  }else{
    leaveOnStack = 0;
    nField = pOp->p1;
  }
  jumpIfNull = pOp->p2;
  addRowid = pOp->opcode==OP_MakeIdxRec || pOp->opcode==OP_RegMakeIRec;
  zAffinity = pOp->p4.p;

  if( pOp->opcode==OP_RegMakeRec || pOp->opcode==OP_RegMakeIRec ){
    Mem *pCount;
    assert( nField>=0 && nField<p->nMem );
    pCount = &p->aMem[nField];
    assert( pCount->flags & MEM_Int );
    assert( pCount->u.i>=0 && pCount->u.i+nField<p->nMem );
................................................................................

    sqlite3ExpirePreparedStatements(db);
    rc = SQLITE_SCHEMA;
  }
  break;
}

/* Opcode: OpenRead P1 P2 P4
**
** Open a read-only cursor for the database table whose root page is
** P2 in a database file.  The database file is determined by an 
** integer from the top of the stack.  0 means the main database and
** 1 means the database used for temporary tables.  Give the new 
** cursor an identifier of P1.  The P1 values need not be contiguous
** but all P1 values should be small integers.  It is an error for
................................................................................
** then a read lock is acquired as part of this instruction.  A read
** lock allows other processes to read the database but prohibits
** any other process from modifying the database.  The read lock is
** released when all cursors are closed.  If this instruction attempts
** to get a read lock but fails, the script terminates with an
** SQLITE_BUSY error code.
**
** The P4 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices.  P4 is NULL for cursors
** that are not pointing to indices.
**
** See also OpenWrite.
*/
/* Opcode: OpenWrite P1 P2 P4
**
** Open a read/write cursor named P1 on the table or index whose root
** page is P2.  If P2==0 then take the root page number from the stack.
**
** The P4 value is a pointer to a KeyInfo structure that defines the
** content and collating sequence of indices.  P4 is NULL for cursors
** that are not pointing to indices.
**
** This instruction works just like OpenRead except that it opens the cursor
** in read/write mode.  For a given table, there can be one or more read-only
** cursors or a single read/write cursor but not both.
**
** See also OpenRead.
................................................................................
  pCur = allocateCursor(p, i, iDb);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  if( pX==0 ) break;
  /* We always provide a key comparison function.  If the table being
  ** opened is of type INTKEY, the comparision function will be ignored. */
  rc = sqlite3BtreeCursor(pX, p2, wrFlag,
           sqlite3VdbeRecordCompare, pOp->p4.p,
           &pCur->pCursor);
  if( pOp->p4type==P4_KEYINFO ){
    pCur->pKeyInfo = (KeyInfo*)pOp->p4.p;
    pCur->pIncrKey = &pCur->pKeyInfo->incrKey;
    pCur->pKeyInfo->enc = ENC(p->db);
  }else{
    pCur->pKeyInfo = 0;
    pCur->pIncrKey = &pCur->bogusIncrKey;
  }
  switch( rc ){
................................................................................
      */
      if( (flags & 0xf0)!=0 || ((flags & 0x07)!=5 && (flags & 0x07)!=2) ){
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }
      pCur->isTable = (flags & BTREE_INTKEY)!=0;
      pCur->isIndex = (flags & BTREE_ZERODATA)!=0;
      /* If P4==0 it means we are expected to open a table.  If P4!=0 then
      ** we expect to be opening an index.  If this is not what happened,
      ** then the database is corrupt
      */
      if( (pCur->isTable && pOp->p4type==P4_KEYINFO)
       || (pCur->isIndex && pOp->p4type!=P4_KEYINFO) ){
        rc = SQLITE_CORRUPT_BKPT;
        goto abort_due_to_error;
      }
      break;
    }
    case SQLITE_EMPTY: {
      pCur->isTable = pOp->p4type!=P4_KEYINFO;
      pCur->isIndex = !pCur->isTable;
      rc = SQLITE_OK;
      break;
    }
    default: {
      goto abort_due_to_error;
    }
  }
  break;
}

/* Opcode: OpenEphemeral P1 P2 P4
**
** Open a new cursor P1 to a transient table.
** The cursor is always opened read/write even if 
** the main database is read-only.  The transient or virtual
** table is deleted automatically when the cursor is closed.
**
** P2 is the number of columns in the virtual table.
** The cursor points to a BTree table if P4==0 and to a BTree index
** if P4 is not 0.  If P4 is not NULL, it points to a KeyInfo structure
** that defines the format of keys in the index.
**
** This opcode was once called OpenTemp.  But that created
** confusion because the term "temp table", might refer either
** to a TEMP table at the SQL level, or to a table opened by
** this opcode.  Then this opcode was call OpenVirtual.  But
** that created confusion with the whole virtual-table idea.
................................................................................
  }
  if( rc==SQLITE_OK ){
    /* If a transient index is required, create it by calling
    ** sqlite3BtreeCreateTable() with the BTREE_ZERODATA flag before
    ** opening it. If a transient table is required, just use the
    ** automatically created table with root-page 1 (an INTKEY table).
    */
    if( pOp->p4.p ){
      int pgno;
      assert( pOp->p4type==P4_KEYINFO );
      rc = sqlite3BtreeCreateTable(pCx->pBt, &pgno, BTREE_ZERODATA); 
      if( rc==SQLITE_OK ){
        assert( pgno==MASTER_ROOT+1 );
        rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, sqlite3VdbeRecordCompare,
            pOp->p4.p, &pCx->pCursor);
        pCx->pKeyInfo = (KeyInfo*)pOp->p4.p;
        pCx->pKeyInfo->enc = ENC(p->db);
        pCx->pIncrKey = &pCx->pKeyInfo->incrKey;
      }
      pCx->isTable = 0;
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, 0, &pCx->pCursor);
      pCx->isTable = 1;
................................................................................
  }
  pTos++;
  pTos->u.i = v;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: Insert P1 P2 P4
**
** Write an entry into the table of cursor P1.  A new entry is
** created if it doesn't already exist or the data for an existing
** entry is overwritten.  The data is the value on the top of the
** stack.  The key is the next value down on the stack.  The key must
** be an integer.  The stack is popped twice by this instruction.
**
** If the OPFLAG_NCHANGE flag of P2 is set, then the row change count is
** incremented (otherwise not).  If the OPFLAG_LASTROWID flag of P2 is set,
** then rowid is stored for subsequent return by the
** sqlite3_last_insert_rowid() function (otherwise it is unmodified).
**
** Parameter P4 may point to a string containing the table-name, or
** may be NULL. If it is not NULL, then the update-hook 
** (sqlite3.xUpdateCallback) is invoked following a successful insert.
**
** This instruction only works on tables.  The equivalent instruction
** for indices is OP_IdxInsert.
*/
case OP_Insert: {         /* no-push */
................................................................................
    }
    
    pC->rowidIsValid = 0;
    pC->deferredMoveto = 0;
    pC->cacheStatus = CACHE_STALE;

    /* Invoke the update-hook if required. */
    if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.p ){
      const char *zDb = db->aDb[pC->iDb].zName;
      const char *zTbl = pOp->p4.p;
      int op = ((pOp->p2 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
      assert( pC->isTable );
      db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
      assert( pC->iDb>=0 );
    }
  }
  popStack(&pTos, 2);

  break;
}

/* Opcode: Delete P1 P2 P4
**
** Delete the record at which the P1 cursor is currently pointing.
**
** The cursor will be left pointing at either the next or the previous
** record in the table. If it is left pointing at the next record, then
** the next Next instruction will be a no-op.  Hence it is OK to delete
** a record from within an Next loop.
................................................................................
  assert( pC!=0 );
  if( pC->pCursor!=0 ){
    i64 iKey;

    /* If the update-hook will be invoked, set iKey to the rowid of the
    ** row being deleted.
    */
    if( db->xUpdateCallback && pOp->p4.p ){
      assert( pC->isTable );
      if( pC->rowidIsValid ){
        iKey = pC->lastRowid;
      }else{
        rc = sqlite3BtreeKeySize(pC->pCursor, &iKey);
        if( rc ){
          goto abort_due_to_error;
................................................................................
    rc = sqlite3VdbeCursorMoveto(pC);
    if( rc ) goto abort_due_to_error;
    rc = sqlite3BtreeDelete(pC->pCursor);
    pC->nextRowidValid = 0;
    pC->cacheStatus = CACHE_STALE;

    /* Invoke the update-hook if required. */
    if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.p ){
      const char *zDb = db->aDb[pC->iDb].zName;
      const char *zTbl = pOp->p4.p;
      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, zTbl, iKey);
      assert( pC->iDb>=0 );
    }
  }
  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
  break;
}
................................................................................
**
** The top of the stack might have fewer columns that P1.
**
** If the P1 index entry is greater than the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
*/
/* Opcode: IdxGE P1 P2 P4
**
** The top of the stack is an index entry that omits the ROWID.  Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is greater than or equal to the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P4 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This make the opcode work
** like IdxGT except that if the key from the stack is a prefix of
** the key in the cursor, the result is false whereas it would be
** true with IdxGT.
*/
/* Opcode: IdxLT P1 P2 P4
**
** The top of the stack is an index entry that omits the ROWID.  Compare
** the top of stack against the index that P1 is currently pointing to.
** Ignore the ROWID on the P1 index.
**
** If the P1 index entry is less than  the top of the stack
** then jump to P2.  Otherwise fall through to the next instruction.
** In either case, the stack is popped once.
**
** If P4 is the "+" string (or any other non-NULL string) then the
** index taken from the top of the stack is temporarily increased by
** an epsilon prior to the comparison.  This makes the opcode work
** like IdxLE.
*/
case OP_IdxLT:          /* no-push */
case OP_IdxGT:          /* no-push */
case OP_IdxGE: {        /* no-push */
................................................................................
  assert( pTos>=p->aStack );
  if( (pC = p->apCsr[i])->pCursor!=0 ){
    int res;
 
    assert( pTos->flags & MEM_Blob );  /* Created using OP_MakeRecord */
    assert( pC->deferredMoveto==0 );
    ExpandBlob(pTos);
    *pC->pIncrKey = pOp->p4.p!=0;
    assert( pOp->p4.p==0 || pOp->opcode!=OP_IdxGT );
    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, (u8*)pTos->z, &res);
    *pC->pIncrKey = 0;
    if( rc!=SQLITE_OK ){
      break;
    }
    if( pOp->opcode==OP_IdxLT ){
      res = -res;
................................................................................
case OP_Clear: {        /* no-push */

  /* For consistency with the way other features of SQLite operate
  ** with a truncate, we will also skip the update callback.
  */
#if 0
  Btree *pBt = db->aDb[pOp->p2].pBt;
  if( db->xUpdateCallback && pOp->p4.p ){
    const char *zDb = db->aDb[pOp->p2].zName;
    const char *zTbl = pOp->p4.p;
    BtCursor *pCur = 0;
    int fin = 0;

    rc = sqlite3BtreeCursor(pBt, pOp->p1, 0, 0, 0, &pCur);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
................................................................................
    pTos->flags = MEM_Int;
  }else{
    pTos->flags = MEM_Null;
  }
  break;
}

/* Opcode: ParseSchema P1 P2 P4
**
** Read and parse all entries from the SQLITE_MASTER table of database P1
** that match the WHERE clause P4.  P2 is the "force" flag.   Always do
** the parsing if P2 is true.  If P2 is false, then this routine is a
** no-op if the schema is not currently loaded.  In other words, if P2
** is false, the SQLITE_MASTER table is only parsed if the rest of the
** schema is already loaded into the symbol table.
**
** This opcode invokes the parser to create a new virtual machine,
** then runs the new virtual machine.  It is thus a reentrant opcode.
................................................................................
  }
  zMaster = SCHEMA_TABLE(iDb);
  initData.db = db;
  initData.iDb = pOp->p1;
  initData.pzErrMsg = &p->zErrMsg;
  zSql = sqlite3MPrintf(db,
     "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s",
     db->aDb[iDb].zName, zMaster, pOp->p4.p);
  if( zSql==0 ) goto no_mem;
  sqlite3SafetyOff(db);
  assert( db->init.busy==0 );
  db->init.busy = 1;
  assert( !db->mallocFailed );
  rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
  if( rc==SQLITE_ABORT ) rc = initData.rc;
................................................................................
  int iDb = pOp->p1;
  assert( iDb>=0 && iDb<db->nDb );
  rc = sqlite3AnalysisLoad(db, iDb);
  break;  
}
#endif /* !defined(SQLITE_OMIT_ANALYZE) && !defined(SQLITE_OMIT_PARSER)  */

/* Opcode: DropTable P1 * P4
**
** Remove the internal (in-memory) data structures that describe
** the table named P4 in database P1.  This is called after a table
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTable: {        /* no-push */
  sqlite3UnlinkAndDeleteTable(db, pOp->p1, pOp->p4.p);
  break;
}

/* Opcode: DropIndex P1 * P4
**
** Remove the internal (in-memory) data structures that describe
** the index named P4 in database P1.  This is called after an index
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropIndex: {        /* no-push */
  sqlite3UnlinkAndDeleteIndex(db, pOp->p1, pOp->p4.p);
  break;
}

/* Opcode: DropTrigger P1 * P4
**
** Remove the internal (in-memory) data structures that describe
** the trigger named P4 in database P1.  This is called after a trigger
** is dropped in order to keep the internal representation of the
** schema consistent with what is on disk.
*/
case OP_DropTrigger: {        /* no-push */
  sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p4.p);
  break;
}


#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Opcode: IntegrityCk P1 P2 *
**
................................................................................
case OP_MemMove: {
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  assert( pOp->p2>=0 && pOp->p2<p->nMem );
  rc = sqlite3VdbeMemMove(&p->aMem[pOp->p1], &p->aMem[pOp->p2]);
  break;
}

/* Opcode: AggStep P1 P2 P4
**
** Execute the step function for an aggregate.  The
** function has P2 arguments.  P4 is a pointer to the FuncDef
** structure that specifies the function.  Use memory location
** P1 as the accumulator.
**
** The P2 arguments are popped from the stack.
*/
case OP_AggStep: {        /* no-push */
  int n = pOp->p2;
................................................................................
  assert( pRec>=p->aStack );
  apVal = p->apArg;
  assert( apVal || n==0 );
  for(i=0; i<n; i++, pRec++){
    apVal[i] = pRec;
    storeTypeInfo(pRec, encoding);
  }
  ctx.pFunc = (FuncDef*)pOp->p4.p;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  ctx.pMem = pMem = &p->aMem[pOp->p1];
  pMem->n++;
  ctx.s.flags = MEM_Null;
  ctx.s.z = 0;
  ctx.s.xDel = 0;
  ctx.s.db = db;
  ctx.isError = 0;
  ctx.pColl = 0;
  if( ctx.pFunc->needCollSeq ){
    assert( pOp>p->aOp );
    assert( pOp[-1].p4type==P4_COLLSEQ );
    assert( pOp[-1].opcode==OP_CollSeq );
    ctx.pColl = (CollSeq *)pOp[-1].p4.p;
  }
  (ctx.pFunc->xStep)(&ctx, n, apVal);
  popStack(&pTos, n);
  if( ctx.isError ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(&ctx.s), (char*)0);
    rc = SQLITE_ERROR;
  }
  sqlite3VdbeMemRelease(&ctx.s);
  break;
}

/* Opcode: AggFinal P1 P2 P4
**
** Execute the finalizer function for an aggregate.  P1 is
** the memory location that is the accumulator for the aggregate.
**
** P2 is the number of arguments that the step function takes and
** P4 is a pointer to the FuncDef for this function.  The P2
** argument is not used by this opcode.  It is only there to disambiguate
** functions that can take varying numbers of arguments.  The
** P4 argument is only needed for the degenerate case where
** the step function was not previously called.
*/
case OP_AggFinal: {        /* no-push */
  Mem *pMem;
  assert( pOp->p1>=0 && pOp->p1<p->nMem );
  pMem = &p->aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  rc = sqlite3VdbeMemFinalize(pMem, (FuncDef*)pOp->p4.p);
  if( rc==SQLITE_ERROR ){
    sqlite3SetString(&p->zErrMsg, sqlite3_value_text(pMem), (char*)0);
  }
  if( sqlite3VdbeMemTooBig(pMem) ){
    goto too_big;
  }
  break;
................................................................................
  }else{
    p->expired = 1;
  }
  break;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/* Opcode: TableLock P1 P2 P4
**
** Obtain a lock on a particular table. This instruction is only used when
** the shared-cache feature is enabled. 
**
** If P1 is not negative, then it is the index of the database
** in sqlite3.aDb[] and a read-lock is required. If P1 is negative, a 
** write-lock is required. In this case the index of the database is the 
** absolute value of P1 minus one (iDb = abs(P1) - 1;) and a write-lock is
** required. 
**
** P2 contains the root-page of the table to lock.
**
** P4 contains a pointer to the name of the table being locked. This is only
** used to generate an error message if the lock cannot be obtained.
*/
case OP_TableLock: {        /* no-push */
  int p1 = pOp->p1; 
  u8 isWriteLock = (p1<0);
  if( isWriteLock ){
    p1 = (-1*p1)-1;
  }
  assert( p1>=0 && p1<db->nDb );
  assert( (p->btreeMask & (1<<p1))!=0 );
  rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
  if( rc==SQLITE_LOCKED ){
    const char *z = (const char *)pOp->p4.p;
    sqlite3SetString(&p->zErrMsg, "database table is locked: ", z, (char*)0);
  }
  break;
}
#endif /* SQLITE_OMIT_SHARED_CACHE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VBegin * * P4
**
** P4 a pointer to an sqlite3_vtab structure. Call the xBegin method 
** for that table.
*/
case OP_VBegin: {   /* no-push */
  rc = sqlite3VtabBegin(db, (sqlite3_vtab *)pOp->p4.p);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VCreate P1 * P4
**
** P4 is the name of a virtual table in database P1. Call the xCreate method
** for that table.
*/
case OP_VCreate: {   /* no-push */
  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.p, &p->zErrMsg);
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VDestroy P1 * P4
**
** P4 is the name of a virtual table in database P1.  Call the xDestroy method
** of that table.
*/
case OP_VDestroy: {   /* no-push */
  p->inVtabMethod = 2;
  rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.p);
  p->inVtabMethod = 0;
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VOpen P1 * P4
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** P1 is a cursor number.  This opcode opens a cursor to the virtual
** table and stores that cursor in P1.
*/
case OP_VOpen: {   /* no-push */
  Cursor *pCur = 0;
  sqlite3_vtab_cursor *pVtabCursor = 0;

  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p4.p);
  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;

  assert(pVtab && pModule);
  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  rc = pModule->xOpen(pVtab, &pVtabCursor);
  if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;
  if( SQLITE_OK==rc ){
................................................................................
    }
  }
  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VFilter P1 P2 P4
**
** P1 is a cursor opened using VOpen.  P2 is an address to jump to if
** the filtered result set is empty.
**
** P4 is either NULL or a string that was generated by the xBestIndex
** method of the module.  The interpretation of the P4 string is left
** to the module implementation.
**
** This opcode invokes the xFilter method on the virtual table specified
** by P1.  The integer query plan parameter to xFilter is the top of the
** stack.  Next down on the stack is the argc parameter.  Beneath the
** next of stack are argc additional parameters which are passed to
** xFilter as argv. The topmost parameter (i.e. 3rd element popped from
................................................................................
    for(i = 0; i<nArg; i++){
      apArg[i] = &pTos[i+1-2-nArg];
      storeTypeInfo(apArg[i], 0);
    }

    if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
    p->inVtabMethod = 1;
    rc = pModule->xFilter(pCur->pVtabCursor, pTos->u.i, pOp->p4.p, nArg, apArg);
    p->inVtabMethod = 0;
    if( rc==SQLITE_OK ){
      res = pModule->xEof(pCur->pVtabCursor);
    }
    if( sqlite3SafetyOn(db) ) goto abort_due_to_misuse;

    if( res ){
................................................................................
  }

  break;
}
#endif /* SQLITE_OMIT_VIRTUALTABLE */

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VRename * * P4
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xRename method. The value
** on the top of the stack is popped and passed as the zName argument
** to the xRename method.
*/
case OP_VRename: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p4.p);
  assert( pVtab->pModule->xRename );

  Stringify(pTos, encoding);

  if( sqlite3SafetyOff(db) ) goto abort_due_to_misuse;
  sqlite3VtabLock(pVtab);
  rc = pVtab->pModule->xRename(pVtab, pTos->z);
................................................................................

  popStack(&pTos, 1);
  break;
}
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Opcode: VUpdate P1 P2 P4
**
** P4 is a pointer to a virtual table object, an sqlite3_vtab structure.
** This opcode invokes the corresponding xUpdate method. P2 values
** are taken from the stack to pass to the xUpdate invocation. The
** value on the top of the stack corresponds to the p2th element 
** of the argv array passed to xUpdate.
**
** The xUpdate method will do a DELETE or an INSERT or both.
** The argv[0] element (which corresponds to the P2-th element down
................................................................................
** a row to delete.
**
** P1 is a boolean flag. If it is set to true and the xUpdate call
** is successful, then the value returned by sqlite3_last_insert_rowid() 
** is set to the value of the rowid for the row just inserted.
*/
case OP_VUpdate: {   /* no-push */
  sqlite3_vtab *pVtab = (sqlite3_vtab *)(pOp->p4.p);
  sqlite3_module *pModule = (sqlite3_module *)pVtab->pModule;
  int nArg = pOp->p2;
  assert( pOp->p4type==P4_VTAB );
  if( pModule->xUpdate==0 ){
    sqlite3SetString(&p->zErrMsg, "read-only table", 0);
    rc = SQLITE_ERROR;
  }else{
    int i;
    sqlite_int64 rowid;
    Mem **apArg = p->apArg;

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.117 2008/01/02 17:25:55 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................
/*
** A single instruction of the virtual machine has an opcode
** and as many as three operands.  The instruction is recorded
** as an instance of the following structure:
*/
struct VdbeOp {
  u8 opcode;          /* What operation to perform */
  char p3type;        /* One of the P3_xxx constants defined below */
  char p4type;        /* One of the P3_xxx constants for p4 */
  u8 p5;              /* Fifth parameter is an unsigned character */
  int p1;             /* First operand */
  int p2;             /* Second parameter (often the jump destination) */

  union {             /* Third and forth parameters */
    int i;              /* Integer value if p3type==P3_INT32 */
    char *p;            /* A pointer for all other value sof p3type */
  } p3, p4;
#ifdef SQLITE_DEBUG
  char *zComment;     /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;            /* Number of times this instruction was executed */
  long long cycles;   /* Total time spend executing this instruction */
#endif
................................................................................
  char *p3;           /* Third parameter */
};
typedef struct VdbeOpList VdbeOpList;

/*
** Allowed values of VdbeOp.p3type
*/
#define P3_NOTUSED    0   /* The P3 parameter is not used */
#define P3_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
#define P3_STATIC   (-2)  /* Pointer to a static string */
#define P3_COLLSEQ  (-4)  /* P3 is a pointer to a CollSeq structure */
#define P3_FUNCDEF  (-5)  /* P3 is a pointer to a FuncDef structure */
#define P3_KEYINFO  (-6)  /* P3 is a pointer to a KeyInfo structure */
#define P3_VDBEFUNC (-7)  /* P3 is a pointer to a VdbeFunc structure */
#define P3_MEM      (-8)  /* P3 is a pointer to a Mem*    structure */
#define P3_TRANSIENT (-9) /* P3 is a pointer to a transient string */
#define P3_VTAB     (-10) /* P3 is a pointer to an sqlite3_vtab structure */
#define P3_MPRINTF  (-11) /* P3 is a string obtained from sqlite3_mprintf() */
#define P3_REAL     (-12) /* P3 is a 64-bit floating point value */
#define P3_INT64    (-13) /* P3 is a 64-bit signed integer */
#define P3_INT32    (-14) /* P3 is a 32-bit signed integer */

/* When adding a P3 argument using P3_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P3_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
*/
#define P3_KEYINFO_HANDOFF (-9)

/*
** The Vdbe.aColName array contains 5n Mem structures, where n is the 
** number of columns of data returned by the statement.
*/
#define COLNAME_NAME     0
#define COLNAME_DECLTYPE 1
................................................................................
#include "opcodes.h"

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqlite3VdbeCreate(sqlite3*);
int sqlite3VdbeAddOp(Vdbe*,int,int,int);

int sqlite3VdbeOp3(Vdbe*,int,int,int,const char *zP3,int);
int sqlite3VdbeOp3Int(Vdbe*,int,int,int,int);

int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
void sqlite3VdbeJumpHere(Vdbe*, int addr);
void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N);
void sqlite3VdbeUsesBtree(Vdbe*, int);
VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
int sqlite3VdbeMakeLabel(Vdbe*);
void sqlite3VdbeDelete(Vdbe*);
void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);
int sqlite3VdbeFinalize(Vdbe*);
void sqlite3VdbeResolveLabel(Vdbe*, int);

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.118 2008/01/03 00:01:25 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines
................................................................................
/*
** A single instruction of the virtual machine has an opcode
** and as many as three operands.  The instruction is recorded
** as an instance of the following structure:
*/
struct VdbeOp {
  u8 opcode;          /* What operation to perform */
  char p4type;        /* One of the P4_xxx constants for p4 */
  u8 flags;           /* Flags for internal use */
  u8 p5;              /* Fifth parameter is an unsigned character */
  int p1;             /* First operand */
  int p2;             /* Second parameter (often the jump destination) */
  int p3;             /* The third parameter */
  union {             /* forth parameter */
    int i;              /* Integer value if p3type==P4_INT32 */
    char *p;            /* A pointer for all other value sof p3type */
  } p4;
#ifdef SQLITE_DEBUG
  char *zComment;     /* Comment to improve readability */
#endif
#ifdef VDBE_PROFILE
  int cnt;            /* Number of times this instruction was executed */
  long long cycles;   /* Total time spend executing this instruction */
#endif
................................................................................
  char *p3;           /* Third parameter */
};
typedef struct VdbeOpList VdbeOpList;

/*
** Allowed values of VdbeOp.p3type
*/
#define P4_NOTUSED    0   /* The P4 parameter is not used */
#define P4_DYNAMIC  (-1)  /* Pointer to a string obtained from sqliteMalloc() */
#define P4_STATIC   (-2)  /* Pointer to a static string */
#define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
#define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
#define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
#define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
#define P4_TRANSIENT (-9) /* P4 is a pointer to a transient string */
#define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
#define P4_MPRINTF  (-11) /* P4 is a string obtained from sqlite3_mprintf() */
#define P4_REAL     (-12) /* P4 is a 64-bit floating point value */
#define P4_INT64    (-13) /* P4 is a 64-bit signed integer */
#define P4_INT32    (-14) /* P4 is a 32-bit signed integer */

/* When adding a P4 argument using P4_KEYINFO, a copy of the KeyInfo structure
** is made.  That copy is freed when the Vdbe is finalized.  But if the
** argument is P4_KEYINFO_HANDOFF, the passed in pointer is used.  It still
** gets freed when the Vdbe is finalized so it still should be obtained
** from a single sqliteMalloc().  But no copy is made and the calling
** function should *not* try to free the KeyInfo.
*/
#define P4_KEYINFO_HANDOFF (-9)

/*
** The Vdbe.aColName array contains 5n Mem structures, where n is the 
** number of columns of data returned by the statement.
*/
#define COLNAME_NAME     0
#define COLNAME_DECLTYPE 1
................................................................................
#include "opcodes.h"

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqlite3VdbeCreate(sqlite3*);
int sqlite3VdbeAddOp0(Vdbe*,int);
int sqlite3VdbeAddOp1(Vdbe*,int,int);
int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
void sqlite3VdbeJumpHere(Vdbe*, int addr);
void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
void sqlite3VdbeUsesBtree(Vdbe*, int);
VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
int sqlite3VdbeMakeLabel(Vdbe*);
void sqlite3VdbeDelete(Vdbe*);
void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);
int sqlite3VdbeFinalize(Vdbe*);
void sqlite3VdbeResolveLabel(Vdbe*, int);

#ifndef SQLITE_OMIT_TRACE
    /* Invoke the trace callback if there is one
    */
    if( db->xTrace && !db->init.busy ){
      assert( p->nOp>0 );
      assert( p->aOp[p->nOp-1].opcode==OP_Noop );
      assert( p->aOp[p->nOp-1].p3.p!=0 );
      assert( p->aOp[p->nOp-1].p3type==P3_DYNAMIC );
      sqlite3SafetyOff(db);
      db->xTrace(db->pTraceArg, p->aOp[p->nOp-1].p3.p);
      if( sqlite3SafetyOn(db) ){
        p->rc = SQLITE_MISUSE;
        return SQLITE_MISUSE;
      }
    }
    if( db->xProfile && !db->init.busy ){
      double rNow;
................................................................................
#endif

    /* Print a copy of SQL as it is executed if the SQL_TRACE pragma is turned
    ** on in debugging mode.
    */
#ifdef SQLITE_DEBUG
    if( (db->flags & SQLITE_SqlTrace)!=0 ){
      sqlite3DebugPrintf("SQL-trace: %s\n", p->aOp[p->nOp-1].p3.p);
    }
#endif /* SQLITE_DEBUG */

    db->activeVdbeCnt++;
    p->pc = 0;
  }
#ifndef SQLITE_OMIT_EXPLAIN
................................................................................
    double rNow;
    u64 elapseTime;

    sqlite3OsCurrentTime(db->pVfs, &rNow);
    elapseTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0 - p->startTime;
    assert( p->nOp>0 );
    assert( p->aOp[p->nOp-1].opcode==OP_Noop );
    assert( p->aOp[p->nOp-1].p3.p!=0 );
    assert( p->aOp[p->nOp-1].p3type==P3_DYNAMIC );
    db->xProfile(db->pProfileArg, p->aOp[p->nOp-1].p3.p, elapseTime);
  }
#endif

  sqlite3Error(p->db, rc, 0);
  p->rc = sqlite3ApiExit(p->db, p->rc);
end_of_step:
  assert( (rc&0xff)==rc );
................................................................................
    sqlite3_mutex_enter(p->db->mutex);
    if( !p->okVar ){
      int j;
      Op *pOp;
      for(j=0, pOp=p->aOp; j<p->nOp; j++, pOp++){
        if( pOp->opcode==OP_Variable ){
          assert( pOp->p1>0 && pOp->p1<=p->nVar );
          p->azVar[pOp->p1-1] = pOp->p3.p;
        }
      }
      p->okVar = 1;
    }
    sqlite3_mutex_leave(p->db->mutex);
  }
}

#ifndef SQLITE_OMIT_TRACE
    /* Invoke the trace callback if there is one
    */
    if( db->xTrace && !db->init.busy ){
      assert( p->nOp>0 );
      assert( p->aOp[p->nOp-1].opcode==OP_Noop );
      assert( p->aOp[p->nOp-1].p4.p!=0 );
      assert( p->aOp[p->nOp-1].p4type==P4_DYNAMIC );
      sqlite3SafetyOff(db);
      db->xTrace(db->pTraceArg, p->aOp[p->nOp-1].p4.p);
      if( sqlite3SafetyOn(db) ){
        p->rc = SQLITE_MISUSE;
        return SQLITE_MISUSE;
      }
    }
    if( db->xProfile && !db->init.busy ){
      double rNow;
................................................................................
#endif

    /* Print a copy of SQL as it is executed if the SQL_TRACE pragma is turned
    ** on in debugging mode.
    */
#ifdef SQLITE_DEBUG
    if( (db->flags & SQLITE_SqlTrace)!=0 ){
      sqlite3DebugPrintf("SQL-trace: %s\n", p->aOp[p->nOp-1].p4.p);
    }
#endif /* SQLITE_DEBUG */

    db->activeVdbeCnt++;
    p->pc = 0;
  }
#ifndef SQLITE_OMIT_EXPLAIN
................................................................................
    double rNow;
    u64 elapseTime;

    sqlite3OsCurrentTime(db->pVfs, &rNow);
    elapseTime = (rNow - (int)rNow)*3600.0*24.0*1000000000.0 - p->startTime;
    assert( p->nOp>0 );
    assert( p->aOp[p->nOp-1].opcode==OP_Noop );
    assert( p->aOp[p->nOp-1].p4.p!=0 );
    assert( p->aOp[p->nOp-1].p4type==P4_DYNAMIC );
    db->xProfile(db->pProfileArg, p->aOp[p->nOp-1].p4.p, elapseTime);
  }
#endif

  sqlite3Error(p->db, rc, 0);
  p->rc = sqlite3ApiExit(p->db, p->rc);
end_of_step:
  assert( (rc&0xff)==rc );
................................................................................
    sqlite3_mutex_enter(p->db->mutex);
    if( !p->okVar ){
      int j;
      Op *pOp;
      for(j=0, pOp=p->aOp; j<p->nOp; j++, pOp++){
        if( pOp->opcode==OP_Variable ){
          assert( pOp->p1>0 && pOp->p1<=p->nVar );
          p->azVar[pOp->p1-1] = pOp->p4.p;
        }
      }
      p->okVar = 1;
    }
    sqlite3_mutex_leave(p->db->mutex);
  }
}

**
** Parameters:
**
**    p               Pointer to the VDBE
**
**    op              The opcode for this instruction
**
**    p1, p2          First two of the three possible operands.
**
** Use the sqlite3VdbeResolveLabel() function to fix an address and
** the sqlite3VdbeChangeP3() function to change the value of the P3
** operand.
*/
int sqlite3VdbeAddOp(Vdbe *p, int op, int p1, int p2){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOpAlloc<=i ){
    resizeOpArray(p, p->nOpAlloc*2 + 100);
................................................................................
    }
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = op;
  pOp->p1 = p1;
  pOp->p2 = p2;
  pOp->p3.p = 0;
  pOp->p3type = P3_NOTUSED;

  p->expired = 0;
#ifdef SQLITE_DEBUG
  if( sqlite3_vdbe_addop_trace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
#endif
  return i;
}

/*
** Add an opcode that includes the p3 value as a pointer.
*/
int sqlite3VdbeOp3(
  Vdbe *p,            /* Add the opcode to this VM */
  int op,             /* The new opcode */
  int p1, int p2,     /* P1 and P2 operands */
  const char *zP3,    /* The P3 operand */
  int p3type          /* P3 operand type */
){
  int addr = sqlite3VdbeAddOp(p, op, p1, p2);
  sqlite3VdbeChangeP3(p, addr, zP3, p3type);
  return addr;
}

/*
** Add an opcode that includes the p3 value as an integer.
*/
int sqlite3VdbeOp3Int(
  Vdbe *p,            /* Add the opcode to this VM */
  int op,             /* The new opcode */
  int p1, int p2,     /* P1 and P2 operands */
  int p3              /* The P3 operand */
){
  int addr = sqlite3VdbeAddOp(p, op, p1, p2);
  if( !p->db->mallocFailed ){
    Op *pOp = &p->aOp[addr];
    pOp->p3.i = p3;
    pOp->p3type = P3_INT32;
  }
  return addr;
}

/*
** Create a new symbolic label for an instruction that has yet to be
** coded.  The symbolic label is really just a negative number.  The
** label can be used as the P2 value of an operation.  Later, when
................................................................................
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){
      int p2 = pIn->p2;
      VdbeOp *pOut = &p->aOp[i+addr];
      pOut->opcode = pIn->opcode;
      pOut->p1 = pIn->p1;
      pOut->p2 = p2<0 ? addr + ADDR(p2) : p2;
      pOut->p3.p = pIn->p3;
      pOut->p3type = pIn->p3 ? P3_STATIC : P3_NOTUSED;
#ifdef SQLITE_DEBUG
      if( sqlite3_vdbe_addop_trace ){
        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
      }
#endif
    }
    p->nOp += nOp;
................................................................................
static void freeEphemeralFunction(FuncDef *pDef){
  if( pDef && (pDef->flags & SQLITE_FUNC_EPHEM)!=0 ){
    sqlite3_free(pDef);
  }
}

/*
** Delete a P3 value if necessary.
*/
static void freeP3(int p3type, void *p3){
  if( p3 ){
    switch( p3type ){
      case P3_REAL:
      case P3_INT64:
      case P3_MPRINTF:
      case P3_DYNAMIC:
      case P3_KEYINFO:
      case P3_KEYINFO_HANDOFF: {
        sqlite3_free(p3);
        break;
      }
      case P3_VDBEFUNC: {
        VdbeFunc *pVdbeFunc = (VdbeFunc *)p3;
        freeEphemeralFunction(pVdbeFunc->pFunc);
        sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
        sqlite3_free(pVdbeFunc);
        break;
      }
      case P3_FUNCDEF: {
        freeEphemeralFunction((FuncDef*)p3);
        break;
      }
      case P3_MEM: {
        sqlite3ValueFree((sqlite3_value*)p3);
        break;
      }
    }
  }
}

................................................................................
/*
** Change N opcodes starting at addr to No-ops.
*/
void sqlite3VdbeChangeToNoop(Vdbe *p, int addr, int N){
  if( p && p->aOp ){
    VdbeOp *pOp = &p->aOp[addr];
    while( N-- ){
      freeP3(pOp->p3type, pOp->p3.p);
      memset(pOp, 0, sizeof(pOp[0]));
      pOp->opcode = OP_Noop;
      pOp++;
    }
  }
}

/*
** Change the value of the P3 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
**
** If n>=0 then the P3 operand is dynamic, meaning that a copy of
** the string is made into memory obtained from sqlite3_malloc().
** A value of n==0 means copy bytes of zP3 up to and including the
** first null byte.  If n>0 then copy n+1 bytes of zP3.
**
** If n==P3_KEYINFO it means that zP3 is a pointer to a KeyInfo structure.
** A copy is made of the KeyInfo structure into memory obtained from
** sqlite3_malloc, to be freed when the Vdbe is finalized.
** n==P3_KEYINFO_HANDOFF indicates that zP3 points to a KeyInfo structure
** stored in memory that the caller has obtained from sqlite3_malloc. The 
** caller should not free the allocation, it will be freed when the Vdbe is
** finalized.
** 
** Other values of n (P3_STATIC, P3_COLLSEQ etc.) indicate that zP3 points
** to a string or structure that is guaranteed to exist for the lifetime of
** the Vdbe. In these cases we can just copy the pointer.
**
** If addr<0 then change P3 on the most recently inserted instruction.
*/
void sqlite3VdbeChangeP3(Vdbe *p, int addr, const char *zP3, int n){
  Op *pOp;
  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
  if( p==0 || p->aOp==0 || p->db->mallocFailed ){
    if (n != P3_KEYINFO) {
      freeP3(n, (void*)*(char**)&zP3);
    }
    return;
  }
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }
  pOp = &p->aOp[addr];
  freeP3(pOp->p3type, pOp->p3.p);
  pOp->p3.p = 0;
  if( zP3==0 ){
    pOp->p3.p = 0;
    pOp->p3type = P3_NOTUSED;
  }else if( n==P3_KEYINFO ){
    KeyInfo *pKeyInfo;
    int nField, nByte;

    nField = ((KeyInfo*)zP3)->nField;
    nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
    pKeyInfo = sqlite3_malloc( nByte );
    pOp->p3.p = (char*)pKeyInfo;
    if( pKeyInfo ){
      unsigned char *aSortOrder;
      memcpy(pKeyInfo, zP3, nByte);
      aSortOrder = pKeyInfo->aSortOrder;
      if( aSortOrder ){
        pKeyInfo->aSortOrder = (unsigned char*)&pKeyInfo->aColl[nField];
        memcpy(pKeyInfo->aSortOrder, aSortOrder, nField);
      }
      pOp->p3type = P3_KEYINFO;
    }else{
      p->db->mallocFailed = 1;
      pOp->p3type = P3_NOTUSED;
    }
  }else if( n==P3_KEYINFO_HANDOFF ){
    pOp->p3.p = (char*)zP3;
    pOp->p3type = P3_KEYINFO;
  }else if( n<0 ){
    pOp->p3.p = (char*)zP3;
    pOp->p3type = n;
  }else{
    if( n==0 ) n = strlen(zP3);
    pOp->p3.p = sqlite3DbStrNDup(p->db, zP3, n);
    pOp->p3type = P3_DYNAMIC;
  }
}

#ifndef NDEBUG
/*
** Change the comment on the the most recently coded instruction.
*/
................................................................................
  assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
  return ((addr>=0 && addr<p->nOp)?(&p->aOp[addr]):0);
}

#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Compute a string that describes the P3 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
static char *displayP3(Op *pOp, char *zTemp, int nTemp){
  char *zP3 = zTemp;
  int nP3;
  assert( nTemp>=20 );
  switch( pOp->p3type ){
    case P3_KEYINFO: {
      int i, j;
      KeyInfo *pKeyInfo = (KeyInfo*)pOp->p3.p;
      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
      i = strlen(zTemp);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        if( pColl ){
          int n = strlen(pColl->zName);
          if( i+n>nTemp-6 ){
................................................................................
        }
      }
      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );
      break;
    }
    case P3_COLLSEQ: {
      CollSeq *pColl = (CollSeq*)pOp->p3.p;
      sqlite3_snprintf(nTemp, zTemp, "collseq(%.20s)", pColl->zName);
      break;
    }
    case P3_FUNCDEF: {
      FuncDef *pDef = (FuncDef*)pOp->p3.p;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
    case P3_INT64: {
      sqlite3_snprintf(nTemp, zTemp, "%lld", *(sqlite3_int64*)pOp->p3.p);
      break;
    }
    case P3_INT32: {
      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p3.i);
      break;
    }
    case P3_REAL: {
      sqlite3_snprintf(nTemp, zTemp, "%.16g", *(double*)pOp->p3.p);
      break;
    }
    case P3_MEM: {
      Mem *pMem = (Mem*)pOp->p3.p;
      if( pMem->flags & MEM_Str ){
        zP3 = pMem->z;
      }else if( pMem->flags & MEM_Int ){
        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
      }else if( pMem->flags & MEM_Real ){
        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->r);
      }else if( pMem->flags & MEM_Null ){
        sqlite3_snprintf(nTemp, zTemp, "NULL");
      }
      break;
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    case P3_VTAB: {
      sqlite3_vtab *pVtab = (sqlite3_vtab*)pOp->p3.p;
      sqlite3_snprintf(nTemp, zTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
      break;
    }
#endif
    default: {
      zP3 = pOp->p3.p;
      if( zP3==0 || pOp->opcode==OP_Noop ){
        zP3 = zTemp;
        zTemp[0] = 0;
      }
    }
  }
  assert( zP3!=0 );
#ifdef SQLITE_DEBUG
  if( pOp->zComment && zP3==zTemp && (nP3 = strlen(zP3))<nTemp ){
    sqlite3_snprintf(nTemp-nP3, &zP3[nP3], "%s# %s",
                     nP3>0 ? " " : "", pOp->zComment);
  }
#endif
  return zP3;
}
#endif

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
**
*/
................................................................................


#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP3;
  char zPtr[50];
  static const char *zFormat1 = "%4d %-13s %4d %4d %s\n";
  if( pOut==0 ) pOut = stdout;
  zP3 = displayP3(pOp, zPtr, sizeof(zPtr));
  fprintf(pOut, zFormat1,
      pc, sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, zP3);
  fflush(pOut);
}
#endif

/*
** Release an array of N Mem elements
*/
................................................................................
    pMem++;

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

    pMem->flags = MEM_Ephem|MEM_Str|MEM_Term;     /* P3 */
    pMem->z = displayP3(pOp, pMem->zShort, sizeof(pMem->zShort));
    assert( pMem->z!=0 );
    pMem->n = strlen(pMem->z);
    pMem->type = SQLITE_TEXT;
    pMem->enc = SQLITE_UTF8;

    p->nResColumn = 5 - 2*(p->explain-1);
    p->pTos = pMem;
................................................................................
** Print the SQL that was used to generate a VDBE program.
*/
void sqlite3VdbePrintSql(Vdbe *p){
  int nOp = p->nOp;
  VdbeOp *pOp;
  if( nOp<1 ) return;
  pOp = &p->aOp[nOp-1];
  if( pOp->opcode==OP_Noop && pOp->p3.p!=0 ){
    const char *z = pOp->p3.p;
    while( isspace(*(u8*)z) ) z++;
    printf("SQL: [%s]\n", z);
  }
}
#endif

#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
................................................................................
*/
void sqlite3VdbeIOTraceSql(Vdbe *p){
  int nOp = p->nOp;
  VdbeOp *pOp;
  if( sqlite3_io_trace==0 ) return;
  if( nOp<1 ) return;
  pOp = &p->aOp[nOp-1];
  if( pOp->opcode==OP_Noop && pOp->p3.p!=0 ){
    int i, j;
    char z[1000];
    sqlite3_snprintf(sizeof(z), z, "%s", pOp->p3.p);
    for(i=0; isspace((unsigned char)z[i]); i++){}
    for(j=0; z[i]; i++){
      if( isspace((unsigned char)z[i]) ){
        if( z[i-1]!=' ' ){
          z[j++] = ' ';
        }
      }else{
................................................................................

/*
** Set the name of the idx'th column to be returned by the SQL statement.
** zName must be a pointer to a nul terminated string.
**
** This call must be made after a call to sqlite3VdbeSetNumCols().
**
** If N==P3_STATIC  it means that zName is a pointer to a constant static
** string and we can just copy the pointer. If it is P3_DYNAMIC, then 
** the string is freed using sqlite3_free() when the vdbe is finished with
** it. Otherwise, N bytes of zName are copied.
*/
int sqlite3VdbeSetColName(Vdbe *p, int idx, int var, const char *zName, int N){
  int rc;
  Mem *pColName;
  assert( idx<p->nResColumn );
  assert( var<COLNAME_N );
  if( p->db->mallocFailed ) return SQLITE_NOMEM;
  assert( p->aColName!=0 );
  pColName = &(p->aColName[idx+var*p->nResColumn]);
  if( N==P3_DYNAMIC || N==P3_STATIC ){
    rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
  }else{
    rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
  }
  if( rc==SQLITE_OK && N==P3_DYNAMIC ){
    pColName->flags = (pColName->flags&(~MEM_Static))|MEM_Dyn;
    pColName->xDel = 0;
  }
  return rc;
}

/*
................................................................................
  }
  if( p->pNext ){
    p->pNext->pPrev = p->pPrev;
  }
  if( p->aOp ){
    Op *pOp = p->aOp;
    for(i=0; i<p->nOp; i++, pOp++){
      freeP3(pOp->p3type, pOp->p3.p);
#ifdef SQLITE_DEBUG
      sqlite3_free(pOp->zComment);
#endif     
    }
    sqlite3_free(p->aOp);
  }
  releaseMemArray(p->aVar, p->nVar);

**
** Parameters:
**
**    p               Pointer to the VDBE
**
**    op              The opcode for this instruction
**
**    p1, p2, p3      Operands
**
** Use the sqlite3VdbeResolveLabel() function to fix an address and
** the sqlite3VdbeChangeP4() function to change the value of the P4
** operand.
*/
int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
  int i;
  VdbeOp *pOp;

  i = p->nOp;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p->nOpAlloc<=i ){
    resizeOpArray(p, p->nOpAlloc*2 + 100);
................................................................................
    }
  }
  p->nOp++;
  pOp = &p->aOp[i];
  pOp->opcode = op;
  pOp->p1 = p1;
  pOp->p2 = p2;
  pOp->p3 = p3;
  pOp->p4.p = 0;
  pOp->p4type = P4_NOTUSED;
  p->expired = 0;
#ifdef SQLITE_DEBUG
  if( sqlite3_vdbe_addop_trace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
#endif
  return i;
}
int sqlite3VdbeAddOp0(Vdbe *p, int op){
  return sqlite3VdbeAddOp3(p, op, 0, 0, 0);
}
int sqlite3VdbeAddOp1(Vdbe *p, int op, int p1){
  return sqlite3VdbeAddOp3(p, op, p1, 0, 0);
}
int sqlite3VdbeAddOp2(Vdbe *p, int op, int p1, int p2){
  return sqlite3VdbeAddOp3(p, op, p1, p2, 0);
}


/*
** Add an opcode that includes the p4 value as a pointer.
*/
int sqlite3VdbeAddOp4(
  Vdbe *p,            /* Add the opcode to this VM */
  int op,             /* The new opcode */
  int p1,             /* The P1 operand */
  int p2,             /* The P2 operand */
  int p3,             /* The P3 operand */
  const char *zP4,    /* The P4 operand */
  int p4type          /* P4 operand type */
){
  int addr = sqlite3VdbeAddOp3(p, op, p1, p2, p3);
  sqlite3VdbeChangeP4(p, addr, zP4, p4type);






  return addr;
}

/*
** Create a new symbolic label for an instruction that has yet to be
** coded.  The symbolic label is really just a negative number.  The
** label can be used as the P2 value of an operation.  Later, when
................................................................................
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){
      int p2 = pIn->p2;
      VdbeOp *pOut = &p->aOp[i+addr];
      pOut->opcode = pIn->opcode;
      pOut->p1 = pIn->p1;
      pOut->p2 = p2<0 ? addr + ADDR(p2) : p2;
      pOut->p4.p = pIn->p3;
      pOut->p4type = pIn->p3 ? P4_STATIC : P4_NOTUSED;
#ifdef SQLITE_DEBUG
      if( sqlite3_vdbe_addop_trace ){
        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
      }
#endif
    }
    p->nOp += nOp;
................................................................................
static void freeEphemeralFunction(FuncDef *pDef){
  if( pDef && (pDef->flags & SQLITE_FUNC_EPHEM)!=0 ){
    sqlite3_free(pDef);
  }
}

/*
** Delete a P4 value if necessary.
*/
static void freeP4(int p4type, void *p3){
  if( p3 ){
    switch( p4type ){
      case P4_REAL:
      case P4_INT64:
      case P4_MPRINTF:
      case P4_DYNAMIC:
      case P4_KEYINFO:
      case P4_KEYINFO_HANDOFF: {
        sqlite3_free(p3);
        break;
      }
      case P4_VDBEFUNC: {
        VdbeFunc *pVdbeFunc = (VdbeFunc *)p3;
        freeEphemeralFunction(pVdbeFunc->pFunc);
        sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
        sqlite3_free(pVdbeFunc);
        break;
      }
      case P4_FUNCDEF: {
        freeEphemeralFunction((FuncDef*)p3);
        break;
      }
      case P4_MEM: {
        sqlite3ValueFree((sqlite3_value*)p3);
        break;
      }
    }
  }
}

................................................................................
/*
** Change N opcodes starting at addr to No-ops.
*/
void sqlite3VdbeChangeToNoop(Vdbe *p, int addr, int N){
  if( p && p->aOp ){
    VdbeOp *pOp = &p->aOp[addr];
    while( N-- ){
      freeP4(pOp->p4type, pOp->p4.p);
      memset(pOp, 0, sizeof(pOp[0]));
      pOp->opcode = OP_Noop;
      pOp++;
    }
  }
}

/*
** Change the value of the P4 operand for a specific instruction.
** This routine is useful when a large program is loaded from a
** static array using sqlite3VdbeAddOpList but we want to make a
** few minor changes to the program.
**
** If n>=0 then the P4 operand is dynamic, meaning that a copy of
** the string is made into memory obtained from sqlite3_malloc().
** A value of n==0 means copy bytes of zP4 up to and including the
** first null byte.  If n>0 then copy n+1 bytes of zP4.
**
** If n==P4_KEYINFO it means that zP4 is a pointer to a KeyInfo structure.
** A copy is made of the KeyInfo structure into memory obtained from
** sqlite3_malloc, to be freed when the Vdbe is finalized.
** n==P4_KEYINFO_HANDOFF indicates that zP4 points to a KeyInfo structure
** stored in memory that the caller has obtained from sqlite3_malloc. The 
** caller should not free the allocation, it will be freed when the Vdbe is
** finalized.
** 
** Other values of n (P4_STATIC, P4_COLLSEQ etc.) indicate that zP4 points
** to a string or structure that is guaranteed to exist for the lifetime of
** the Vdbe. In these cases we can just copy the pointer.
**
** If addr<0 then change P4 on the most recently inserted instruction.
*/
void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
  Op *pOp;
  assert( p==0 || p->magic==VDBE_MAGIC_INIT );
  if( p==0 || p->aOp==0 || p->db->mallocFailed ){
    if (n != P4_KEYINFO) {
      freeP4(n, (void*)*(char**)&zP4);
    }
    return;
  }
  if( addr<0 || addr>=p->nOp ){
    addr = p->nOp - 1;
    if( addr<0 ) return;
  }
  pOp = &p->aOp[addr];
  freeP4(pOp->p4type, pOp->p4.p);
  pOp->p4.p = 0;
  if( zP4==0 ){
    pOp->p4.p = 0;
    pOp->p4type = P4_NOTUSED;
  }else if( n==P4_KEYINFO ){
    KeyInfo *pKeyInfo;
    int nField, nByte;

    nField = ((KeyInfo*)zP4)->nField;
    nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
    pKeyInfo = sqlite3_malloc( nByte );
    pOp->p4.p = (char*)pKeyInfo;
    if( pKeyInfo ){
      unsigned char *aSortOrder;
      memcpy(pKeyInfo, zP4, nByte);
      aSortOrder = pKeyInfo->aSortOrder;
      if( aSortOrder ){
        pKeyInfo->aSortOrder = (unsigned char*)&pKeyInfo->aColl[nField];
        memcpy(pKeyInfo->aSortOrder, aSortOrder, nField);
      }
      pOp->p4type = P4_KEYINFO;
    }else{
      p->db->mallocFailed = 1;
      pOp->p4type = P4_NOTUSED;
    }
  }else if( n==P4_KEYINFO_HANDOFF ){
    pOp->p4.p = (char*)zP4;
    pOp->p4type = P4_KEYINFO;
  }else if( n<0 ){
    pOp->p4.p = (char*)zP4;
    pOp->p4type = n;
  }else{
    if( n==0 ) n = strlen(zP4);
    pOp->p4.p = sqlite3DbStrNDup(p->db, zP4, n);
    pOp->p4type = P4_DYNAMIC;
  }
}

#ifndef NDEBUG
/*
** Change the comment on the the most recently coded instruction.
*/
................................................................................
  assert( (addr>=0 && addr<p->nOp) || p->db->mallocFailed );
  return ((addr>=0 && addr<p->nOp)?(&p->aOp[addr]):0);
}

#if !defined(SQLITE_OMIT_EXPLAIN) || !defined(NDEBUG) \
     || defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Compute a string that describes the P4 parameter for an opcode.
** Use zTemp for any required temporary buffer space.
*/
static char *displayP4(Op *pOp, char *zTemp, int nTemp){
  char *zP4 = zTemp;
  int nP4;
  assert( nTemp>=20 );
  switch( pOp->p4type ){
    case P4_KEYINFO: {
      int i, j;
      KeyInfo *pKeyInfo = (KeyInfo*)pOp->p4.p;
      sqlite3_snprintf(nTemp, zTemp, "keyinfo(%d", pKeyInfo->nField);
      i = strlen(zTemp);
      for(j=0; j<pKeyInfo->nField; j++){
        CollSeq *pColl = pKeyInfo->aColl[j];
        if( pColl ){
          int n = strlen(pColl->zName);
          if( i+n>nTemp-6 ){
................................................................................
        }
      }
      zTemp[i++] = ')';
      zTemp[i] = 0;
      assert( i<nTemp );
      break;
    }
    case P4_COLLSEQ: {
      CollSeq *pColl = (CollSeq*)pOp->p4.p;
      sqlite3_snprintf(nTemp, zTemp, "collseq(%.20s)", pColl->zName);
      break;
    }
    case P4_FUNCDEF: {
      FuncDef *pDef = (FuncDef*)pOp->p4.p;
      sqlite3_snprintf(nTemp, zTemp, "%s(%d)", pDef->zName, pDef->nArg);
      break;
    }
    case P4_INT64: {
      sqlite3_snprintf(nTemp, zTemp, "%lld", *(sqlite3_int64*)pOp->p4.p);
      break;
    }
    case P4_INT32: {
      sqlite3_snprintf(nTemp, zTemp, "%d", pOp->p4.i);
      break;
    }
    case P4_REAL: {
      sqlite3_snprintf(nTemp, zTemp, "%.16g", *(double*)pOp->p4.p);
      break;
    }
    case P4_MEM: {
      Mem *pMem = (Mem*)pOp->p4.p;
      if( pMem->flags & MEM_Str ){
        zP4 = pMem->z;
      }else if( pMem->flags & MEM_Int ){
        sqlite3_snprintf(nTemp, zTemp, "%lld", pMem->u.i);
      }else if( pMem->flags & MEM_Real ){
        sqlite3_snprintf(nTemp, zTemp, "%.16g", pMem->r);
      }else if( pMem->flags & MEM_Null ){
        sqlite3_snprintf(nTemp, zTemp, "NULL");
      }
      break;
    }
#ifndef SQLITE_OMIT_VIRTUALTABLE
    case P4_VTAB: {
      sqlite3_vtab *pVtab = (sqlite3_vtab*)pOp->p4.p;
      sqlite3_snprintf(nTemp, zTemp, "vtab:%p:%p", pVtab, pVtab->pModule);
      break;
    }
#endif
    default: {
      zP4 = pOp->p4.p;
      if( zP4==0 || pOp->opcode==OP_Noop ){
        zP4 = zTemp;
        zTemp[0] = 0;
      }
    }
  }
  assert( zP4!=0 );
#ifdef SQLITE_DEBUG
  if( pOp->zComment && zP4==zTemp && (nP4 = strlen(zP4))<nTemp ){
    sqlite3_snprintf(nTemp-nP4, &zP4[nP4], "%s# %s",
                     nP4>0 ? " " : "", pOp->zComment);
  }
#endif
  return zP4;
}
#endif

/*
** Declare to the Vdbe that the BTree object at db->aDb[i] is used.
**
*/
................................................................................


#if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
/*
** Print a single opcode.  This routine is used for debugging only.
*/
void sqlite3VdbePrintOp(FILE *pOut, int pc, Op *pOp){
  char *zP4;
  char zPtr[50];
  static const char *zFormat1 = "%4d %-13s %4d %4d %s\n";
  if( pOut==0 ) pOut = stdout;
  zP4 = displayP4(pOp, zPtr, sizeof(zPtr));
  fprintf(pOut, zFormat1,
      pc, sqlite3OpcodeName(pOp->opcode), pOp->p1, pOp->p2, zP4);
  fflush(pOut);
}
#endif

/*
** Release an array of N Mem elements
*/
................................................................................
    pMem++;

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

    pMem->flags = MEM_Ephem|MEM_Str|MEM_Term;     /* P4 */
    pMem->z = displayP4(pOp, pMem->zShort, sizeof(pMem->zShort));
    assert( pMem->z!=0 );
    pMem->n = strlen(pMem->z);
    pMem->type = SQLITE_TEXT;
    pMem->enc = SQLITE_UTF8;

    p->nResColumn = 5 - 2*(p->explain-1);
    p->pTos = pMem;
................................................................................
** Print the SQL that was used to generate a VDBE program.
*/
void sqlite3VdbePrintSql(Vdbe *p){
  int nOp = p->nOp;
  VdbeOp *pOp;
  if( nOp<1 ) return;
  pOp = &p->aOp[nOp-1];
  if( pOp->opcode==OP_Noop && pOp->p4.p!=0 ){
    const char *z = pOp->p4.p;
    while( isspace(*(u8*)z) ) z++;
    printf("SQL: [%s]\n", z);
  }
}
#endif

#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
................................................................................
*/
void sqlite3VdbeIOTraceSql(Vdbe *p){
  int nOp = p->nOp;
  VdbeOp *pOp;
  if( sqlite3_io_trace==0 ) return;
  if( nOp<1 ) return;
  pOp = &p->aOp[nOp-1];
  if( pOp->opcode==OP_Noop && pOp->p4.p!=0 ){
    int i, j;
    char z[1000];
    sqlite3_snprintf(sizeof(z), z, "%s", pOp->p4.p);
    for(i=0; isspace((unsigned char)z[i]); i++){}
    for(j=0; z[i]; i++){
      if( isspace((unsigned char)z[i]) ){
        if( z[i-1]!=' ' ){
          z[j++] = ' ';
        }
      }else{
................................................................................

/*
** Set the name of the idx'th column to be returned by the SQL statement.
** zName must be a pointer to a nul terminated string.
**
** This call must be made after a call to sqlite3VdbeSetNumCols().
**
** If N==P4_STATIC  it means that zName is a pointer to a constant static
** string and we can just copy the pointer. If it is P4_DYNAMIC, then 
** the string is freed using sqlite3_free() when the vdbe is finished with
** it. Otherwise, N bytes of zName are copied.
*/
int sqlite3VdbeSetColName(Vdbe *p, int idx, int var, const char *zName, int N){
  int rc;
  Mem *pColName;
  assert( idx<p->nResColumn );
  assert( var<COLNAME_N );
  if( p->db->mallocFailed ) return SQLITE_NOMEM;
  assert( p->aColName!=0 );
  pColName = &(p->aColName[idx+var*p->nResColumn]);
  if( N==P4_DYNAMIC || N==P4_STATIC ){
    rc = sqlite3VdbeMemSetStr(pColName, zName, -1, SQLITE_UTF8, SQLITE_STATIC);
  }else{
    rc = sqlite3VdbeMemSetStr(pColName, zName, N, SQLITE_UTF8,SQLITE_TRANSIENT);
  }
  if( rc==SQLITE_OK && N==P4_DYNAMIC ){
    pColName->flags = (pColName->flags&(~MEM_Static))|MEM_Dyn;
    pColName->xDel = 0;
  }
  return rc;
}

/*
................................................................................
  }
  if( p->pNext ){
    p->pNext->pPrev = p->pPrev;
  }
  if( p->aOp ){
    Op *pOp = p->aOp;
    for(i=0; i<p->nOp; i++, pOp++){
      freeP4(pOp->p4type, pOp->p4.p);
#ifdef SQLITE_DEBUG
      sqlite3_free(pOp->zComment);
#endif     
    }
    sqlite3_free(p->aOp);
  }
  releaseMemArray(p->aVar, p->nVar);

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to help implement virtual tables.
**
** $Id: vtab.c,v 1.59 2007/09/20 11:32:18 rse Exp $
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#include "sqliteInt.h"

static int createModule(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
................................................................................
      pTab->zName,
      zStmt
    );
    sqlite3_free(zStmt);
    v = sqlite3GetVdbe(pParse);
    sqlite3ChangeCookie(db, v, iDb);

    sqlite3VdbeAddOp(v, OP_Expire, 0, 0);
    zWhere = sqlite3MPrintf(db, "name='%q'", pTab->zName);
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 1, zWhere, P3_DYNAMIC);

    sqlite3VdbeOp3(v, OP_VCreate, iDb, 0, pTab->zName, strlen(pTab->zName) + 1);
  }

  /* If we are rereading the sqlite_master table create the in-memory
  ** record of the table. If the module has already been registered,
  ** also call the xConnect method here.
  */
  else {

**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains code used to help implement virtual tables.
**
** $Id: vtab.c,v 1.60 2008/01/03 00:01:25 drh Exp $
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#include "sqliteInt.h"

static int createModule(
  sqlite3 *db,                    /* Database in which module is registered */
  const char *zName,              /* Name assigned to this module */
................................................................................
      pTab->zName,
      zStmt
    );
    sqlite3_free(zStmt);
    v = sqlite3GetVdbe(pParse);
    sqlite3ChangeCookie(db, v, iDb);

    sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
    zWhere = sqlite3MPrintf(db, "name='%q'", pTab->zName);
    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 1, 0, zWhere, P4_DYNAMIC);
    sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, 
                         pTab->zName, strlen(pTab->zName) + 1);
  }

  /* If we are rereading the sqlite_master table create the in-memory
  ** record of the table. If the module has already been registered,
  ** also call the xConnect method here.
  */
  else {

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.267 2008/01/02 00:34:37 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
** problem.
*/
static void buildIndexProbe(
  Vdbe *v,        /* Generate code into this VM */
  int nColumn,    /* The number of columns to check for NULL */
  Index *pIdx     /* Index that we will be searching */
){
  sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
  sqlite3IndexAffinityStr(v, pIdx);
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
................................................................................
  WhereLevel *pLevel  /* When level of the FROM clause we are working on */
){
  Expr *pX = pTerm->pExpr;
  Vdbe *v = pParse->pVdbe;
  if( pX->op==TK_EQ ){
    sqlite3ExprCode(pParse, pX->pRight);
  }else if( pX->op==TK_ISNULL ){
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
#ifndef SQLITE_OMIT_SUBQUERY
  }else{
    int eType;
    int iTab;
    struct InLoop *pIn;

    assert( pX->op==TK_IN );
    eType = sqlite3FindInIndex(pParse, pX, 1);
    iTab = pX->iTable;
    sqlite3VdbeAddOp(v, OP_Rewind, iTab, 0);
    VdbeComment((v, "%.*s", pX->span.n, pX->span.z));
    if( pLevel->nIn==0 ){
      pLevel->nxt = sqlite3VdbeMakeLabel(v);
    }
    pLevel->nIn++;
    pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
                                    sizeof(pLevel->aInLoop[0])*pLevel->nIn);
    pIn = pLevel->aInLoop;
    if( pIn ){
      int op = ((eType==IN_INDEX_ROWID)?OP_Rowid:OP_Column);
      pIn += pLevel->nIn - 1;
      pIn->iCur = iTab;
      pIn->topAddr = sqlite3VdbeAddOp(v, op, iTab, 0);
      sqlite3VdbeAddOp(v, OP_IsNull, -1, 0);
    }else{
      pLevel->nIn = 0;
    }
#endif
  }
  disableTerm(pLevel, pTerm);
}
................................................................................
  for(j=0; j<nEq; j++){
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    if( pTerm==0 ) break;
    assert( (pTerm->flags & TERM_CODED)==0 );
    codeEqualityTerm(pParse, pTerm, pLevel);
    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
      sqlite3VdbeAddOp(v, OP_IsNull, termsInMem ? -1 : -(j+1), pLevel->brk);
    }
    if( termsInMem ){
      sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem+j+1, 1);
    }
  }

  /* Make sure all the constraint values are on the top of the stack
  */
  if( termsInMem ){
    for(j=0; j<nEq; j++){
      sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem+j+1, 0);
    }
  }
}

#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
................................................................................
        zMsg = sqlite3MPrintf(db, "%z VIRTUAL TABLE INDEX %d:%s", zMsg,
                    pBestIdx->idxNum, pBestIdx->idxStr);
      }
#endif
      if( pLevel->flags & WHERE_ORDERBY ){
        zMsg = sqlite3MPrintf(db, "%z ORDER BY", zMsg);
      }
      sqlite3VdbeOp3(v, OP_Explain, i, pLevel->iFrom, zMsg, P3_DYNAMIC);
    }
#endif /* SQLITE_OMIT_EXPLAIN */
    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pTab;
    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
    if( pTab->isEphem || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pBestIdx ){
      int iCur = pTabItem->iCursor;

      sqlite3VdbeOp3(v, OP_VOpen, iCur, 0, (const char*)pTab->pVtab, P3_VTAB);
    }else
#endif
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, OP_OpenRead);
      if( pTab->nCol<(sizeof(Bitmask)*8) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
................................................................................
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    pLevel->iTabCur = pTabItem->iCursor;
    if( (pIx = pLevel->pIdx)!=0 ){
      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
      assert( pIx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
      VdbeComment((v, "%s", pIx->zName));
      sqlite3VdbeOp3(v, OP_OpenRead, iIdxCur, pIx->tnum,
                     (char*)pKey, P3_KEYINFO_HANDOFF);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, iIdxCur, pIx->nColumn+1);
    }
    sqlite3CodeVerifySchema(pParse, iDb);
  }
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
................................................................................
    /* If this is the right table of a LEFT OUTER JOIN, allocate and
    ** initialize a memory cell that records if this table matches any
    ** row of the left table of the join.
    */
    if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
      if( !pParse->nMem ) pParse->nMem++;
      pLevel->iLeftJoin = pParse->nMem++;
      sqlite3VdbeAddOp(v, OP_MemInt, 0, pLevel->iLeftJoin);
      VdbeComment((v, "init LEFT JOIN no-match flag"));
    }

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pBestIdx ){
      /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
      **          to access the data.
................................................................................
            int iTerm = aConstraint[k].iTermOffset;
            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight);
            break;
          }
        }
        if( k==nConstraint ) break;
      }
      sqlite3VdbeAddOp(v, OP_Integer, j-1, 0);
      sqlite3VdbeAddOp(v, OP_Integer, pBestIdx->idxNum, 0);
      sqlite3VdbeOp3(v, OP_VFilter, iCur, brk, pBestIdx->idxStr,
                      pBestIdx->needToFreeIdxStr ? P3_MPRINTF : P3_STATIC);
      pBestIdx->needToFreeIdxStr = 0;
      for(j=0; j<pBestIdx->nConstraint; j++){
        if( aUsage[j].omit ){
          int iTerm = aConstraint[j].iTermOffset;
          disableTerm(pLevel, &wc.a[iTerm]);
        }
      }
................................................................................
      pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
      assert( pTerm!=0 );
      assert( pTerm->pExpr!=0 );
      assert( pTerm->leftCursor==iCur );
      assert( omitTable==0 );
      codeEqualityTerm(pParse, pTerm, pLevel);
      nxt = pLevel->nxt;
      sqlite3VdbeAddOp(v, OP_MustBeInt, 1, nxt);
      sqlite3VdbeAddOp(v, OP_NotExists, iCur, nxt);
      VdbeComment((v, "pk"));
      pLevel->op = OP_Noop;
    }else if( pLevel->flags & WHERE_ROWID_RANGE ){
      /* Case 2:  We have an inequality comparison against the ROWID field.
      */
      int testOp = OP_Noop;
      int start;
................................................................................
      }
      if( pStart ){
        Expr *pX;
        pX = pStart->pExpr;
        assert( pX!=0 );
        assert( pStart->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp(v, OP_ForceInt, pX->op==TK_LE || pX->op==TK_GT, brk);
        sqlite3VdbeAddOp(v, bRev ? OP_MoveLt : OP_MoveGe, iCur, brk);
        VdbeComment((v, "pk"));
        disableTerm(pLevel, pStart);
      }else{
        sqlite3VdbeAddOp(v, bRev ? OP_Last : OP_Rewind, iCur, brk);
      }
      if( pEnd ){
        Expr *pX;
        pX = pEnd->pExpr;
        assert( pX!=0 );
        assert( pEnd->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight);
        pLevel->iMem = pParse->nMem++;
        sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
        if( pX->op==TK_LT || pX->op==TK_GT ){
          testOp = bRev ? OP_Le : OP_Ge;
        }else{
          testOp = bRev ? OP_Lt : OP_Gt;
        }
        disableTerm(pLevel, pEnd);
      }
      start = sqlite3VdbeCurrentAddr(v);
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = start;
      if( testOp!=OP_Noop ){
        sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
        sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp(v, testOp, SQLITE_AFF_NUMERIC|0x100, brk);
      }
    }else if( pLevel->flags & WHERE_COLUMN_RANGE ){
      /* Case 3: The WHERE clause term that refers to the right-most
      **         column of the index is an inequality.  For example, if
      **         the index is on (x,y,z) and the WHERE clause is of the
      **         form "x=5 AND y<10" then this case is used.  Only the
      **         right-most column can be an inequality - the rest must
................................................................................
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);

      /* Duplicate the equality term values because they will all be
      ** used twice: once to make the termination key and once to make the
      ** start key.
      */
      for(j=0; j<nEq; j++){
        sqlite3VdbeAddOp(v, OP_Dup, nEq-1, 0);
      }

      /* Figure out what comparison operators to use for top and bottom 
      ** search bounds. For an ascending index, the bottom bound is a > or >=
      ** operator and the top bound is a < or <= operator.  For a descending
      ** index the operators are reversed.
      */
................................................................................
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, topOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp(v, OP_IsNull, -(nEq*2+1), nxt);
        topEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
        testOp = OP_IdxGE;
      }else{
        testOp = nEq>0 ? OP_IdxGE : OP_Noop;
        topEq = 1;
      }
      if( testOp!=OP_Noop ){
        int nCol = nEq + topLimit;
        pLevel->iMem = pParse->nMem++;
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp(v, op, iIdxCur, nxt);
        }else{
          sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
        }
      }else if( bRev ){
        sqlite3VdbeAddOp(v, OP_Last, iIdxCur, brk);
      }

      /* Generate the start key.  This is the key that defines the lower
      ** bound on the search.  There is no start key if there are no
      ** equality terms and if there is no "X>..." term.  In
      ** that case, generate a "Rewind" instruction in place of the
      ** start key search.
................................................................................
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, btmOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp(v, OP_IsNull, -(nEq+1), nxt);
        btmEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
      }else{
        btmEq = 1;
      }
      if( nEq>0 || btmLimit ){
        int nCol = nEq + btmLimit;
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          pLevel->iMem = pParse->nMem++;
          sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
          testOp = OP_IdxLT;
        }else{
          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp(v, op, iIdxCur, nxt);
        }
      }else if( bRev ){
        testOp = OP_Noop;
      }else{
        sqlite3VdbeAddOp(v, OP_Rewind, iIdxCur, brk);
      }

      /* Generate the the top of the loop.  If there is a termination
      ** key we have to test for that key and abort at the top of the
      ** loop.
      */
      start = sqlite3VdbeCurrentAddr(v);
      if( testOp!=OP_Noop ){
        sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp(v, testOp, iIdxCur, nxt);
        if( (topEq && !bRev) || (!btmEq && bRev) ){
          sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
        }
      }
      if( topLimit | btmLimit ){
        sqlite3VdbeAddOp(v, OP_Column, iIdxCur, nEq);
        sqlite3VdbeAddOp(v, OP_IsNull, 1, cont);
      }
      if( !omitTable ){
        sqlite3VdbeAddOp(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
      }

      /* Record the instruction used to terminate the loop.
      */
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
................................................................................
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);
      nxt = pLevel->nxt;

      /* Generate a single key that will be used to both start and terminate
      ** the search
      */
      buildIndexProbe(v, nEq, pIdx);
      sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 0);

      /* Generate code (1) to move to the first matching element of the table.
      ** Then generate code (2) that jumps to "nxt" after the cursor is past
      ** the last matching element of the table.  The code (1) is executed
      ** once to initialize the search, the code (2) is executed before each
      ** iteration of the scan to see if the scan has finished. */
      if( bRev ){
        /* Scan in reverse order */
        sqlite3VdbeAddOp(v, OP_MoveLe, iIdxCur, nxt);
        start = sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp(v, OP_IdxLT, iIdxCur, nxt);
        pLevel->op = OP_Prev;
      }else{
        /* Scan in the forward order */
        sqlite3VdbeAddOp(v, OP_MoveGe, iIdxCur, nxt);
        start = sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeOp3(v, OP_IdxGE, iIdxCur, nxt, "+", P3_STATIC);
        pLevel->op = OP_Next;
      }
      if( !omitTable ){
        sqlite3VdbeAddOp(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
      }
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else{
      /* Case 5:  There is no usable index.  We must do a complete
      **          scan of the entire table.
      */
      assert( omitTable==0 );
      assert( bRev==0 );
      pLevel->op = OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp(v, OP_Rewind, iCur, brk);
    }
    notReady &= ~getMask(&maskSet, iCur);
    sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);

    /* Insert code to test every subexpression that can be completely
    ** computed using the current set of tables.
    */
    for(pTerm=wc.a, j=wc.nTerm; j>0; j--, pTerm++){
      Expr *pE;
      if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
................................................................................
    }

    /* For a LEFT OUTER JOIN, generate code that will record the fact that
    ** at least one row of the right table has matched the left table.  
    */
    if( pLevel->iLeftJoin ){
      pLevel->top = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_MemInt, 1, pLevel->iLeftJoin);
      VdbeComment((v, "record LEFT JOIN hit"));
      for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){
        if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
        if( (pTerm->prereqAll & notReady)!=0 ) continue;
        assert( pTerm->pExpr );
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, 1);
        pTerm->flags |= TERM_CODED;
................................................................................

  /* Generate loop termination code.
  */
  for(i=pTabList->nSrc-1; i>=0; i--){
    pLevel = &pWInfo->a[i];
    sqlite3VdbeResolveLabel(v, pLevel->cont);
    if( pLevel->op!=OP_Noop ){
      sqlite3VdbeAddOp(v, pLevel->op, pLevel->p1, pLevel->p2);
    }
    if( pLevel->nIn ){
      struct InLoop *pIn;
      int j;
      sqlite3VdbeResolveLabel(v, pLevel->nxt);
      for(j=pLevel->nIn, pIn=&pLevel->aInLoop[j-1]; j>0; j--, pIn--){
        sqlite3VdbeJumpHere(v, pIn->topAddr+1);
        sqlite3VdbeAddOp(v, OP_Next, pIn->iCur, pIn->topAddr);
        sqlite3VdbeJumpHere(v, pIn->topAddr-1);
      }
      sqlite3_free(pLevel->aInLoop);
    }
    sqlite3VdbeResolveLabel(v, pLevel->brk);
    if( pLevel->iLeftJoin ){
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_IfMemPos, pLevel->iLeftJoin, 0);
      sqlite3VdbeAddOp(v, OP_NullRow, pTabList->a[i].iCursor, 0);
      if( pLevel->iIdxCur>=0 ){
        sqlite3VdbeAddOp(v, OP_NullRow, pLevel->iIdxCur, 0);
      }
      sqlite3VdbeAddOp(v, OP_Goto, 0, pLevel->top);
      sqlite3VdbeJumpHere(v, addr);
    }
  }

  /* The "break" point is here, just past the end of the outer loop.
  ** Set it.
  */
................................................................................
  */
  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
    Table *pTab = pTabItem->pTab;
    assert( pTab!=0 );
    if( pTab->isEphem || pTab->pSelect ) continue;
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3VdbeAddOp(v, OP_Close, pTabItem->iCursor, 0);
    }
    if( pLevel->pIdx!=0 ){
      sqlite3VdbeAddOp(v, OP_Close, pLevel->iIdxCur, 0);
    }

    /* If this scan uses an index, make code substitutions to read data
    ** from the index in preference to the table. Sometimes, this means
    ** the table need never be read from. This is a performance boost,
    ** as the vdbe level waits until the table is read before actually
    ** seeking the table cursor to the record corresponding to the current

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.268 2008/01/03 00:01:26 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
................................................................................
** problem.
*/
static void buildIndexProbe(
  Vdbe *v,        /* Generate code into this VM */
  int nColumn,    /* The number of columns to check for NULL */
  Index *pIdx     /* Index that we will be searching */
){
  sqlite3VdbeAddOp2(v, OP_MakeRecord, nColumn, 0);
  sqlite3IndexAffinityStr(v, pIdx);
}


/*
** Generate code for a single equality term of the WHERE clause.  An equality
** term can be either X=expr or X IN (...).   pTerm is the term to be 
................................................................................
  WhereLevel *pLevel  /* When level of the FROM clause we are working on */
){
  Expr *pX = pTerm->pExpr;
  Vdbe *v = pParse->pVdbe;
  if( pX->op==TK_EQ ){
    sqlite3ExprCode(pParse, pX->pRight);
  }else if( pX->op==TK_ISNULL ){
    sqlite3VdbeAddOp2(v, OP_Null, 0, 0);
#ifndef SQLITE_OMIT_SUBQUERY
  }else{
    int eType;
    int iTab;
    struct InLoop *pIn;

    assert( pX->op==TK_IN );
    eType = sqlite3FindInIndex(pParse, pX, 1);
    iTab = pX->iTable;
    sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
    VdbeComment((v, "%.*s", pX->span.n, pX->span.z));
    if( pLevel->nIn==0 ){
      pLevel->nxt = sqlite3VdbeMakeLabel(v);
    }
    pLevel->nIn++;
    pLevel->aInLoop = sqlite3DbReallocOrFree(pParse->db, pLevel->aInLoop,
                                    sizeof(pLevel->aInLoop[0])*pLevel->nIn);
    pIn = pLevel->aInLoop;
    if( pIn ){
      int op = ((eType==IN_INDEX_ROWID)?OP_Rowid:OP_Column);
      pIn += pLevel->nIn - 1;
      pIn->iCur = iTab;
      pIn->topAddr = sqlite3VdbeAddOp2(v, op, iTab, 0);
      sqlite3VdbeAddOp2(v, OP_IsNull, -1, 0);
    }else{
      pLevel->nIn = 0;
    }
#endif
  }
  disableTerm(pLevel, pTerm);
}
................................................................................
  for(j=0; j<nEq; j++){
    int k = pIdx->aiColumn[j];
    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx);
    if( pTerm==0 ) break;
    assert( (pTerm->flags & TERM_CODED)==0 );
    codeEqualityTerm(pParse, pTerm, pLevel);
    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
      sqlite3VdbeAddOp2(v, OP_IsNull, termsInMem ? -1 : -(j+1), pLevel->brk);
    }
    if( termsInMem ){
      sqlite3VdbeAddOp2(v, OP_MemStore, pLevel->iMem+j+1, 1);
    }
  }

  /* Make sure all the constraint values are on the top of the stack
  */
  if( termsInMem ){
    for(j=0; j<nEq; j++){
      sqlite3VdbeAddOp2(v, OP_MemLoad, pLevel->iMem+j+1, 0);
    }
  }
}

#if defined(SQLITE_TEST)
/*
** The following variable holds a text description of query plan generated
................................................................................
        zMsg = sqlite3MPrintf(db, "%z VIRTUAL TABLE INDEX %d:%s", zMsg,
                    pBestIdx->idxNum, pBestIdx->idxStr);
      }
#endif
      if( pLevel->flags & WHERE_ORDERBY ){
        zMsg = sqlite3MPrintf(db, "%z ORDER BY", zMsg);
      }
      sqlite3VdbeAddOp4(v, OP_Explain, i, pLevel->iFrom, 0, zMsg, P4_DYNAMIC);
    }
#endif /* SQLITE_OMIT_EXPLAIN */
    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pTab;
    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
    if( pTab->isEphem || pTab->pSelect ) continue;
#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pBestIdx ){
      int iCur = pTabItem->iCursor;
      sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0,
                        (const char*)pTab->pVtab, P4_VTAB);
    }else
#endif
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, OP_OpenRead);
      if( pTab->nCol<(sizeof(Bitmask)*8) ){
        Bitmask b = pTabItem->colUsed;
        int n = 0;
................................................................................
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    pLevel->iTabCur = pTabItem->iCursor;
    if( (pIx = pLevel->pIdx)!=0 ){
      KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
      assert( pIx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp2(v, OP_Integer, iDb, 0);
      VdbeComment((v, "%s", pIx->zName));
      sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, 0,
                        (char*)pKey, P4_KEYINFO_HANDOFF);
      sqlite3VdbeAddOp2(v, OP_SetNumColumns, iIdxCur, pIx->nColumn+1);
    }
    sqlite3CodeVerifySchema(pParse, iDb);
  }
  pWInfo->iTop = sqlite3VdbeCurrentAddr(v);

  /* Generate the code to do the search.  Each iteration of the for
  ** loop below generates code for a single nested loop of the VM
................................................................................
    /* If this is the right table of a LEFT OUTER JOIN, allocate and
    ** initialize a memory cell that records if this table matches any
    ** row of the left table of the join.
    */
    if( pLevel->iFrom>0 && (pTabItem[0].jointype & JT_LEFT)!=0 ){
      if( !pParse->nMem ) pParse->nMem++;
      pLevel->iLeftJoin = pParse->nMem++;
      sqlite3VdbeAddOp2(v, OP_MemInt, 0, pLevel->iLeftJoin);
      VdbeComment((v, "init LEFT JOIN no-match flag"));
    }

#ifndef SQLITE_OMIT_VIRTUALTABLE
    if( pLevel->pBestIdx ){
      /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
      **          to access the data.
................................................................................
            int iTerm = aConstraint[k].iTermOffset;
            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight);
            break;
          }
        }
        if( k==nConstraint ) break;
      }
      sqlite3VdbeAddOp2(v, OP_Integer, j-1, 0);
      sqlite3VdbeAddOp2(v, OP_Integer, pBestIdx->idxNum, 0);
      sqlite3VdbeAddOp4(v, OP_VFilter, iCur, brk, 0, pBestIdx->idxStr,
                        pBestIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
      pBestIdx->needToFreeIdxStr = 0;
      for(j=0; j<pBestIdx->nConstraint; j++){
        if( aUsage[j].omit ){
          int iTerm = aConstraint[j].iTermOffset;
          disableTerm(pLevel, &wc.a[iTerm]);
        }
      }
................................................................................
      pTerm = findTerm(&wc, iCur, -1, notReady, WO_EQ|WO_IN, 0);
      assert( pTerm!=0 );
      assert( pTerm->pExpr!=0 );
      assert( pTerm->leftCursor==iCur );
      assert( omitTable==0 );
      codeEqualityTerm(pParse, pTerm, pLevel);
      nxt = pLevel->nxt;
      sqlite3VdbeAddOp2(v, OP_MustBeInt, 1, nxt);
      sqlite3VdbeAddOp2(v, OP_NotExists, iCur, nxt);
      VdbeComment((v, "pk"));
      pLevel->op = OP_Noop;
    }else if( pLevel->flags & WHERE_ROWID_RANGE ){
      /* Case 2:  We have an inequality comparison against the ROWID field.
      */
      int testOp = OP_Noop;
      int start;
................................................................................
      }
      if( pStart ){
        Expr *pX;
        pX = pStart->pExpr;
        assert( pX!=0 );
        assert( pStart->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp2(v, OP_ForceInt, pX->op==TK_LE || pX->op==TK_GT, brk);
        sqlite3VdbeAddOp2(v, bRev ? OP_MoveLt : OP_MoveGe, iCur, brk);
        VdbeComment((v, "pk"));
        disableTerm(pLevel, pStart);
      }else{
        sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, brk);
      }
      if( pEnd ){
        Expr *pX;
        pX = pEnd->pExpr;
        assert( pX!=0 );
        assert( pEnd->leftCursor==iCur );
        sqlite3ExprCode(pParse, pX->pRight);
        pLevel->iMem = pParse->nMem++;
        sqlite3VdbeAddOp2(v, OP_MemStore, pLevel->iMem, 1);
        if( pX->op==TK_LT || pX->op==TK_GT ){
          testOp = bRev ? OP_Le : OP_Ge;
        }else{
          testOp = bRev ? OP_Lt : OP_Gt;
        }
        disableTerm(pLevel, pEnd);
      }
      start = sqlite3VdbeCurrentAddr(v);
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = start;
      if( testOp!=OP_Noop ){
        sqlite3VdbeAddOp2(v, OP_Rowid, iCur, 0);
        sqlite3VdbeAddOp2(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp2(v, testOp, SQLITE_AFF_NUMERIC|0x100, brk);
      }
    }else if( pLevel->flags & WHERE_COLUMN_RANGE ){
      /* Case 3: The WHERE clause term that refers to the right-most
      **         column of the index is an inequality.  For example, if
      **         the index is on (x,y,z) and the WHERE clause is of the
      **         form "x=5 AND y<10" then this case is used.  Only the
      **         right-most column can be an inequality - the rest must
................................................................................
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);

      /* Duplicate the equality term values because they will all be
      ** used twice: once to make the termination key and once to make the
      ** start key.
      */
      for(j=0; j<nEq; j++){
        sqlite3VdbeAddOp2(v, OP_Dup, nEq-1, 0);
      }

      /* Figure out what comparison operators to use for top and bottom 
      ** search bounds. For an ascending index, the bottom bound is a > or >=
      ** operator and the top bound is a < or <= operator.  For a descending
      ** index the operators are reversed.
      */
................................................................................
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, topOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp2(v, OP_IsNull, -(nEq*2+1), nxt);
        topEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
        testOp = OP_IdxGE;
      }else{
        testOp = nEq>0 ? OP_IdxGE : OP_Noop;
        topEq = 1;
      }
      if( testOp!=OP_Noop ){
        int nCol = nEq + topLimit;
        pLevel->iMem = pParse->nMem++;
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp2(v, op, iIdxCur, nxt);
        }else{
          sqlite3VdbeAddOp2(v, OP_MemStore, pLevel->iMem, 1);
        }
      }else if( bRev ){
        sqlite3VdbeAddOp2(v, OP_Last, iIdxCur, brk);
      }

      /* Generate the start key.  This is the key that defines the lower
      ** bound on the search.  There is no start key if there are no
      ** equality terms and if there is no "X>..." term.  In
      ** that case, generate a "Rewind" instruction in place of the
      ** start key search.
................................................................................
        Expr *pX;
        int k = pIdx->aiColumn[j];
        pTerm = findTerm(&wc, iCur, k, notReady, btmOp, pIdx);
        assert( pTerm!=0 );
        pX = pTerm->pExpr;
        assert( (pTerm->flags & TERM_CODED)==0 );
        sqlite3ExprCode(pParse, pX->pRight);
        sqlite3VdbeAddOp2(v, OP_IsNull, -(nEq+1), nxt);
        btmEq = pTerm->eOperator & (WO_LE|WO_GE);
        disableTerm(pLevel, pTerm);
      }else{
        btmEq = 1;
      }
      if( nEq>0 || btmLimit ){
        int nCol = nEq + btmLimit;
        buildIndexProbe(v, nCol, pIdx);
        if( bRev ){
          pLevel->iMem = pParse->nMem++;
          sqlite3VdbeAddOp2(v, OP_MemStore, pLevel->iMem, 1);
          testOp = OP_IdxLT;
        }else{
          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp2(v, op, iIdxCur, nxt);
        }
      }else if( bRev ){
        testOp = OP_Noop;
      }else{
        sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, brk);
      }

      /* Generate the the top of the loop.  If there is a termination
      ** key we have to test for that key and abort at the top of the
      ** loop.
      */
      start = sqlite3VdbeCurrentAddr(v);
      if( testOp!=OP_Noop ){
        sqlite3VdbeAddOp2(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp2(v, testOp, iIdxCur, nxt);
        if( (topEq && !bRev) || (!btmEq && bRev) ){
          sqlite3VdbeChangeP4(v, -1, "+", P4_STATIC);
        }
      }
      if( topLimit | btmLimit ){
        sqlite3VdbeAddOp2(v, OP_Column, iIdxCur, nEq);
        sqlite3VdbeAddOp2(v, OP_IsNull, 1, cont);
      }
      if( !omitTable ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp2(v, OP_MoveGe, iCur, 0);
      }

      /* Record the instruction used to terminate the loop.
      */
      pLevel->op = bRev ? OP_Prev : OP_Next;
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
................................................................................
      codeAllEqualityTerms(pParse, pLevel, &wc, notReady);
      nxt = pLevel->nxt;

      /* Generate a single key that will be used to both start and terminate
      ** the search
      */
      buildIndexProbe(v, nEq, pIdx);
      sqlite3VdbeAddOp2(v, OP_MemStore, pLevel->iMem, 0);

      /* Generate code (1) to move to the first matching element of the table.
      ** Then generate code (2) that jumps to "nxt" after the cursor is past
      ** the last matching element of the table.  The code (1) is executed
      ** once to initialize the search, the code (2) is executed before each
      ** iteration of the scan to see if the scan has finished. */
      if( bRev ){
        /* Scan in reverse order */
        sqlite3VdbeAddOp2(v, OP_MoveLe, iIdxCur, nxt);
        start = sqlite3VdbeAddOp2(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp2(v, OP_IdxLT, iIdxCur, nxt);
        pLevel->op = OP_Prev;
      }else{
        /* Scan in the forward order */
        sqlite3VdbeAddOp2(v, OP_MoveGe, iIdxCur, nxt);
        start = sqlite3VdbeAddOp2(v, OP_MemLoad, pLevel->iMem, 0);
        sqlite3VdbeAddOp4(v, OP_IdxGE, iIdxCur, nxt, 0, "+", P4_STATIC);
        pLevel->op = OP_Next;
      }
      if( !omitTable ){
        sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, 0);
        sqlite3VdbeAddOp2(v, OP_MoveGe, iCur, 0);
      }
      pLevel->p1 = iIdxCur;
      pLevel->p2 = start;
    }else{
      /* Case 5:  There is no usable index.  We must do a complete
      **          scan of the entire table.
      */
      assert( omitTable==0 );
      assert( bRev==0 );
      pLevel->op = OP_Next;
      pLevel->p1 = iCur;
      pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, brk);
    }
    notReady &= ~getMask(&maskSet, iCur);
    sqlite3VdbeAddOp2(v, OP_StackDepth, -1, 0);

    /* Insert code to test every subexpression that can be completely
    ** computed using the current set of tables.
    */
    for(pTerm=wc.a, j=wc.nTerm; j>0; j--, pTerm++){
      Expr *pE;
      if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
................................................................................
    }

    /* For a LEFT OUTER JOIN, generate code that will record the fact that
    ** at least one row of the right table has matched the left table.  
    */
    if( pLevel->iLeftJoin ){
      pLevel->top = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_MemInt, 1, pLevel->iLeftJoin);
      VdbeComment((v, "record LEFT JOIN hit"));
      for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){
        if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
        if( (pTerm->prereqAll & notReady)!=0 ) continue;
        assert( pTerm->pExpr );
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, 1);
        pTerm->flags |= TERM_CODED;
................................................................................

  /* Generate loop termination code.
  */
  for(i=pTabList->nSrc-1; i>=0; i--){
    pLevel = &pWInfo->a[i];
    sqlite3VdbeResolveLabel(v, pLevel->cont);
    if( pLevel->op!=OP_Noop ){
      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
    }
    if( pLevel->nIn ){
      struct InLoop *pIn;
      int j;
      sqlite3VdbeResolveLabel(v, pLevel->nxt);
      for(j=pLevel->nIn, pIn=&pLevel->aInLoop[j-1]; j>0; j--, pIn--){
        sqlite3VdbeJumpHere(v, pIn->topAddr+1);
        sqlite3VdbeAddOp2(v, OP_Next, pIn->iCur, pIn->topAddr);
        sqlite3VdbeJumpHere(v, pIn->topAddr-1);
      }
      sqlite3_free(pLevel->aInLoop);
    }
    sqlite3VdbeResolveLabel(v, pLevel->brk);
    if( pLevel->iLeftJoin ){
      int addr;
      addr = sqlite3VdbeAddOp2(v, OP_IfMemPos, pLevel->iLeftJoin, 0);
      sqlite3VdbeAddOp2(v, OP_NullRow, pTabList->a[i].iCursor, 0);
      if( pLevel->iIdxCur>=0 ){
        sqlite3VdbeAddOp2(v, OP_NullRow, pLevel->iIdxCur, 0);
      }
      sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->top);
      sqlite3VdbeJumpHere(v, addr);
    }
  }

  /* The "break" point is here, just past the end of the outer loop.
  ** Set it.
  */
................................................................................
  */
  for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
    struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
    Table *pTab = pTabItem->pTab;
    assert( pTab!=0 );
    if( pTab->isEphem || pTab->pSelect ) continue;
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3VdbeAddOp2(v, OP_Close, pTabItem->iCursor, 0);
    }
    if( pLevel->pIdx!=0 ){
      sqlite3VdbeAddOp2(v, OP_Close, pLevel->iIdxCur, 0);
    }

    /* If this scan uses an index, make code substitutions to read data
    ** from the index in preference to the table. Sometimes, this means
    ** the table need never be read from. This is a performance boost,
    ** as the vdbe level waits until the table is read before actually
    ** seeking the table cursor to the record corresponding to the current