SQLite

**    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 1.165 2008/03/31 23:48:04 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.

      sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j);
      sqlite3ColumnDefault(v, pTab, idx);
    }
  }
  if( doMakeRec ){
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut);
    sqlite3IndexAffinityStr(v, pIdx);
    sqlite3ExprExpireColumnCacheLines(pParse, regBase, regBase+nCol);
  }
  sqlite3ReleaseTempRange(pParse, regBase, nCol+1);
  return regBase;
}

/* Make sure "isView" gets undefined in case this file becomes part of
** the amalgamation - so that subsequent files do not see isView as a
** macro. */
#undef isView

**    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 1.359 2008/03/31 23:48:04 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

          */
          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          pParse->disableColCache++;
          sqlite3ExprCode(pParse, pE2, r1);
          pParse->disableColCache--;
          sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
          sqlite3ExprExpireColumnCacheLines(pParse, r1, r1);
          sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);
        }
        sqlite3ReleaseTempReg(pParse, r1);
        sqlite3ReleaseTempReg(pParse, r2);
      }
      sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
      break;

    }
  }
}


/*
** Generate code that will extract the iColumn-th column from
** table pTab and store the column value in a register.  An effort
** is made to store the column value in register iReg, but this is
** not guaranteed.  The location of the column value is returned.
**
** There must be an open cursor to pTab in iTable when this routine
** is called.  If iColumn<0 then code is generated that extracts the rowid.
*/
int sqlite3ExprCodeGetColumn(
  Parse *pParse,   /* Parsing and code generating context */
  Table *pTab,     /* Description of the table we are reading from */
  int iColumn,     /* Index of the table column */
  int iTable,      /* The cursor pointing to the table */
  int iReg         /* Store results here */
){
  Vdbe *v = pParse->pVdbe;
  int i;

  for(i=0; i<pParse->nColCache; i++){
    if( pParse->aColCache[i].iTable==iTable
     && pParse->aColCache[i].iColumn==iColumn ){
#if 0
      sqlite3VdbeAddOp0(v, OP_Noop);
      VdbeComment((v, "OPT: tab%d.col%d -> r%d",
                       iTable, iColumn, pParse->aColCache[i].iReg));
#endif
      return pParse->aColCache[i].iReg;
    }
  }  
  assert( v!=0 );
  if( iColumn<0 ){
    int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
    sqlite3VdbeAddOp2(v, op, iTable, iReg);
  }else if( pTab==0 ){
    sqlite3VdbeAddOp3(v, OP_Column, iTable, iColumn, iReg);
  }else{
    int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
    sqlite3VdbeAddOp3(v, op, iTable, iColumn, iReg);
    sqlite3ColumnDefault(v, pTab, iColumn);
#ifndef SQLITE_OMIT_FLOATING_POINT
    if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
      sqlite3VdbeAddOp1(v, OP_RealAffinity, iReg);
    }
#endif
  }
  if( pParse->disableColCache==0 ){
    i = pParse->iColCache;
    pParse->aColCache[i].iTable = iTable;
    pParse->aColCache[i].iColumn = iColumn;
    pParse->aColCache[i].iReg = iReg;
    i++;
    if( i>ArraySize(pParse->aColCache) ) i = 0;
    if( i>pParse->nColCache ) pParse->nColCache = i;
  }
  return iReg;
}

/*
** Disable (+1) or enable (-1) the adding of new column cache entries.
*/
void sqlite3ExprColumnCacheDisable(Parse *pParse, int disable){
  assert( disable==-1 || disable==+1 );
  assert( pParse->disableColCache>0 || disable==1 );
  pParse->disableColCache += disable;
}

/*
** Clear all column cache entries associated with the vdbe
** cursor with cursor number iTable.
*/
void sqlite3ExprClearColumnCache(Parse *pParse, int iTable){
  if( iTable<0 ){
    pParse->nColCache = 0;
    pParse->iColCache = 0;
  }else{
    int i;
    for(i=0; i<pParse->nColCache; i++){
      if( pParse->aColCache[i].iTable==iTable ){
        pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
      }
    }
    pParse->iColCache = pParse->nColCache;
  }
}

/*
** Expire all column cache entry associated with register between
** iFrom and iTo, inclusive.  If there are no column cache entries 
** on those registers then this routine is a no-op.
**
** Call this routine when register contents are overwritten to
** make sure the new register value is not used in place of the
** value that was overwritten.
*/
void sqlite3ExprExpireColumnCacheLines(Parse *pParse, int iFrom, int iTo){
  int i;
  for(i=0; i<pParse->nColCache; i++){
    int r = pParse->aColCache[i].iReg;
    if( r>=iFrom && r<=iTo ){
      pParse->aColCache[i] = pParse->aColCache[--pParse->nColCache];
    }
  }
  pParse->iColCache = pParse->nColCache;
}

/*
** Generate code to moves content from one register to another.
** Keep the column cache up-to-date.
*/
void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo){
  int i;
  if( iFrom==iTo ) return;
  sqlite3VdbeAddOp2(pParse->pVdbe, OP_Move, iFrom, iTo);
  for(i=0; i<pParse->nColCache; i++){
    if( pParse->aColCache[i].iReg==iFrom ){
      pParse->aColCache[i].iReg = iTo;
    }
  }
}

/*
** Generate code into the current Vdbe to evaluate the given
** expression.  Attempt to store the results in register "target".
** Return the register where results are stored.

    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){
        /* This only happens when coding check constraints */
        assert( pParse->ckBase>0 );
        inReg = pExpr->iColumn + pParse->ckBase;
      }else{
        inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
                                 pExpr->iColumn, pExpr->iTable, target);
      }
      break;
    }
    case TK_INTEGER: {
      codeInteger(v, (char*)pExpr->token.z, pExpr->token.n, 0, target);
      break;

          codeReal(v, (char*)p->z, p->n, 1, target);
        }else{
          codeInteger(v, (char*)p->z, p->n, 1, target);
        }
      }else{
        regFree1 = r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp2(v, OP_Integer, 0, r1);
        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree2);
        sqlite3VdbeAddOp3(v, OP_Subtract, r2, r1, target);
      }
      inReg = target;
      break;
    }
    case TK_BITNOT:
    case TK_NOT: {

      }
      sqlite3VdbeAddOp4(v, OP_Function, constMask, r1, target,
                        (char*)pDef, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, nExpr);
      if( nExpr ){
        sqlite3ReleaseTempRange(pParse, r1, nExpr);
      }
      sqlite3ExprExpireColumnCacheLines(pParse, r1, r1+nExpr-1);
      break;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_EXISTS:
    case TK_SELECT: {
      if( pExpr->iColumn==0 ){
        sqlite3CodeSubselect(pParse, pExpr);

        j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, r1);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);
        sqlite3VdbeJumpHere(v, j4);
      }else{
        r2 = regFree2 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, r1, 1, r2, &affinity, 1);
        sqlite3ExprExpireColumnCacheLines(pParse, r1, r1);
        j5 = sqlite3VdbeAddOp3(v, OP_Found, pExpr->iTable, 0, r2);
      }
      sqlite3VdbeAddOp2(v, OP_AddImm, target, -1);
      sqlite3VdbeJumpHere(v, j2);
      sqlite3VdbeJumpHere(v, j5);
      break;
    }

      assert(pExpr->pList);
      assert((pExpr->pList->nExpr % 2) == 0);
      assert(pExpr->pList->nExpr > 0);
      pEList = pExpr->pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      sqlite3ExprColumnCacheDisable(pParse, 1);
      if( (pX = pExpr->pLeft)!=0 ){
        cacheX = *pX;
        cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, &regFree1);
        cacheX.op = TK_REGISTER;
        cacheX.iColumn = 0;
        opCompare.op = TK_EQ;
        opCompare.pLeft = &cacheX;

      }
      if( pExpr->pRight ){
        sqlite3ExprCode(pParse, pExpr->pRight, target);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
      }
      sqlite3VdbeResolveLabel(v, endLabel);
      sqlite3ExprColumnCacheDisable(pParse, -1);
      break;
    }
#ifndef SQLITE_OMIT_TRIGGER
    case TK_RAISE: {
      if( !pParse->trigStack ){
        sqlite3ErrorMsg(pParse,
                       "RAISE() may only be used within a trigger-program");

  assert( jumpIfNull==SQLITE_JUMPIFNULL || jumpIfNull==0 );
  if( v==0 || pExpr==0 ) return;
  op = pExpr->op;
  switch( op ){
    case TK_AND: {
      int d2 = sqlite3VdbeMakeLabel(v);
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);
      pParse->disableColCache++;
      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
      pParse->disableColCache--;
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_OR: {
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      pParse->disableColCache++;
      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
      pParse->disableColCache--;
      break;
    }
    case TK_NOT: {
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_LT:

  assert( pExpr->op!=TK_LE || op==OP_Gt );
  assert( pExpr->op!=TK_GT || op==OP_Le );
  assert( pExpr->op!=TK_GE || op==OP_Lt );

  switch( pExpr->op ){
    case TK_AND: {
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      pParse->disableColCache++;
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      pParse->disableColCache--;
      break;
    }
    case TK_OR: {
      int d2 = sqlite3VdbeMakeLabel(v);
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);
      pParse->disableColCache++;
      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
      pParse->disableColCache--;
      sqlite3VdbeResolveLabel(v, d2);
      break;
    }
    case TK_NOT: {
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }

  int i;
  if( pList ){
    for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
      sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
    }
  }
}

/*
** Return true if any register in the range iFrom..iTo (inclusive)
** is used as part of the column cache.
*/
static int usedAsColumnCache(Parse *pParse, int iFrom, int iTo){
  int i;
  for(i=0; i<pParse->nColCache; i++){
    int r = pParse->aColCache[i].iReg;
    if( r>=iFrom && r<=iTo ) return 1;
  }
  return 0;
}

/*
** Allocate or deallocate temporary use registers during code generation.
*/
int sqlite3GetTempReg(Parse *pParse){
  int i, r;
  if( pParse->nTempReg==0 ){
    return ++pParse->nMem;
  }
  for(i=0; i<pParse->nTempReg; i++){
    r = pParse->aTempReg[i];
    if( usedAsColumnCache(pParse, r, r) ) continue;
  }
  if( i>=pParse->nTempReg ){
    return ++pParse->nMem;
  }
  while( i<pParse->nTempReg-1 ){
    pParse->aTempReg[i] = pParse->aTempReg[i+1];
  }
  pParse->nTempReg--;
  return r;
}
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
  if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
    assert( iReg>0 );
    pParse->aTempReg[pParse->nTempReg++] = iReg;
  }
}

/*
** Allocate or deallocate a block of nReg consecutive registers
*/
int sqlite3GetTempRange(Parse *pParse, int nReg){
  int i, n;

  i = pParse->iRangeReg;
  n = pParse->nRangeReg;
  if( nReg<=n && !usedAsColumnCache(pParse, i, i+n-1) ){
    pParse->iRangeReg += nReg;
    pParse->nRangeReg -= nReg;
  }else{
    i = pParse->nMem+1;
    pParse->nMem += nReg;
  }
  return i;

**    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 1.234 2008/03/31 23:48:05 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:

      }else{
        sqlite3VdbeAddOp2(v, OP_SCopy, regData+idx, regIdx+i);
      }
    }
    sqlite3VdbeAddOp2(v, OP_SCopy, regRowid, regIdx+i);
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn+1, aRegIdx[iCur]);
    sqlite3IndexAffinityStr(v, pIdx);
    sqlite3ExprExpireColumnCacheLines(pParse, regIdx, regIdx+pIdx->nColumn);
    sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);

    /* 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( aRegIdx[i]==0 ) continue;
    sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
  }
  regData = regRowid + 1;
  regRec = sqlite3GetTempReg(pParse);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regData, pTab->nCol, regRec);
  sqlite3TableAffinityStr(v, pTab);
  sqlite3ExprExpireColumnCacheLines(pParse, regData, regData+pTab->nCol-1);
#ifndef SQLITE_OMIT_TRIGGER
  if( newIdx>=0 ){
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRec, regRowid);
  }
#endif
  if( pParse->nested ){
    pik_flags = 0;

**    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 1.424 2008/03/31 23:48:05 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

*/
Expr *sqlite3CreateIdExpr(Parse *pParse, const char *zName){
  Token dummy;
  setToken(&dummy, zName);
  return sqlite3PExpr(pParse, TK_ID, 0, 0, &dummy);
}


/*
** Add a term to the WHERE expression in *ppExpr that requires the
** zCol column to be equal in the two tables pTab1 and pTab2.
*/
static void addWhereTerm(
  Parse *pParse,           /* Parsing context */
  const char *zCol,        /* Name of the column */

){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    int iLimit;

        ** 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 */
        pushOntoSorter(pParse, pOrderBy, p, regResult);
      }else{
        int r1 = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult, 1, r1, &p->affinity, 1);
        sqlite3ExprExpireColumnCacheLines(pParse, regResult, regResult);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }
      sqlite3VdbeJumpHere(v, addr2);
      break;
    }

    ** of the scan loop.
    */
    case SRT_Mem: {
      assert( nColumn==1 );
      if( pOrderBy ){
        pushOntoSorter(pParse, pOrderBy, p, regResult);
      }else{
        sqlite3ExprCodeMove(pParse, regResult, iParm);
        /* 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

        sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nColumn, r1);
        pushOntoSorter(pParse, pOrderBy, p, r1);
        sqlite3ReleaseTempReg(pParse, r1);
      }else if( eDest==SRT_Subroutine ){
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }else{
        sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nColumn);
        sqlite3ExprExpireColumnCacheLines(pParse,regResult,regResult+nColumn-1);
      }
      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

    }
#ifndef SQLITE_OMIT_SUBQUERY
    case SRT_Set: {
      int j1;
      assert( nColumn==1 );
      j1 = sqlite3VdbeAddOp1(v, OP_IsNull, regRow);
      sqlite3VdbeAddOp4(v, OP_MakeRecord, regRow, 1, regRowid, &p->affinity, 1);
      sqlite3ExprExpireColumnCacheLines(pParse, regRow, regRow);
      sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm, regRowid);
      sqlite3VdbeJumpHere(v, j1);
      break;
    }
    case SRT_Mem: {
      assert( nColumn==1 );
      sqlite3ExprCodeMove(pParse, regRow, iParm);
      /* The LIMIT clause will terminate the loop for us */
      break;
    }
#endif
    case SRT_Callback:
    case SRT_Subroutine: {
      int i;
      sqlite3VdbeAddOp2(v, OP_Integer, 1, regRowid);
      sqlite3VdbeAddOp3(v, OP_Insert, pseudoTab, regRow, regRowid);
      for(i=0; i<nColumn; i++){
        assert( regRow!=pDest->iMem+i );
        sqlite3VdbeAddOp3(v, OP_Column, pseudoTab, i, pDest->iMem+i);
      }
      if( eDest==SRT_Callback ){
        sqlite3VdbeAddOp2(v, OP_ResultRow, pDest->iMem, nColumn);
        sqlite3ExprExpireColumnCacheLines(pParse, pDest->iMem,
                                                  pDest->iMem+nColumn-1);
      }else{
        sqlite3VdbeAddOp2(v, OP_Gosub, 0, iParm);
      }
      break;
    }
    default: {
      /* Do nothing */

      }
      sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
    }
    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
                      (void*)pF->pFunc, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, nArg);
    sqlite3ReleaseTempRange(pParse, regAgg, nArg);
    sqlite3ExprExpireColumnCacheLines(pParse, regAgg, regAgg+nArg-1);
    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
    }
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
  }

        regBase = sqlite3GetTempRange(pParse, nCol);
        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase);
        sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx,regBase+nGroupBy);
        j = nGroupBy+1;
        for(i=0; i<sAggInfo.nColumn; i++){
          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
          if( pCol->iSorterColumn>=j ){

            int r1 = j + regBase;
            int r2 = sqlite3ExprCodeGetColumn(pParse, 
                               pCol->pTab, pCol->iColumn,  pCol->iTable, r1);
            if( r1!=r2 ){
              sqlite3VdbeAddOp2(v, OP_SCopy, r2, r1);
            }
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);

      ** 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++){
        sqlite3ExprCodeMove(pParse, iBMem+j, iAMem+j);
      }
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrOutputRow);
      VdbeComment((v, "output one row"));
      sqlite3VdbeAddOp2(v, OP_IfPos, iAbortFlag, addrEnd);
      VdbeComment((v, "check abort flag"));
      sqlite3VdbeAddOp2(v, OP_Gosub, 0, addrReset);
      VdbeComment((v, "reset accumulator"));

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.683 2008/03/31 23:48:05 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if it was run
** (otherwise we get an empty default).

  int nRangeReg;       /* Size of the temporary register block */
  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nSet;            /* Number of sets used so far */
  int ckBase;          /* Base register of data during check constraints */
  int disableColCache; /* True to disable adding to column cache */
  int nColCache;       /* Number of entries in the column cache */
  int iColCache;       /* Next entry of the cache to replace */
  struct {
    int iTable;           /* Table cursor number */
    int iColumn;          /* Table column number */
    int iReg;             /* Register holding value of this column */
  } aColCache[10];     /* One for each valid column cache entry */
  u32 writeMask;       /* Start a write transaction on these databases */
  u32 cookieMask;      /* Bitmask of schema verified databases */
  int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
  int cookieValue[SQLITE_MAX_ATTACHED+2];  /* Values of cookies to verify */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nTableLock;        /* Number of locks in aTableLock */
  TableLock *aTableLock; /* Required table locks for shared-cache mode */

Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);
void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8);
void sqlite3WhereEnd(WhereInfo*);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int);
void sqlite3ExprClearColumnCache(Parse*, int);
void sqlite3ExprColumnCacheDisable(Parse*, int);
void sqlite3ExprExpireColumnCacheLines(Parse*, int, int);
int sqlite3ExprCode(Parse*, Expr*, int);
int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
int sqlite3ExprCodeTarget(Parse*, Expr*, int);
int sqlite3ExprCodeAndCache(Parse*, Expr*, int);
void sqlite3ExprCodeConstants(Parse*, Expr*);
int sqlite3ExprCodeExprList(Parse*, ExprList*, int);
void sqlite3ExprIfTrue(Parse*, Expr*, int, int);

**    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 1.174 2008/03/31 23:48:05 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_VIRTUALTABLE
/* Forward declaration */
static void updateVirtualTable(
  Parse *pParse,       /* The parsing context */

      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, regCols+i);
      }
    }
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regCols, pTab->nCol, regRow);
    if( !isView ){
      sqlite3TableAffinityStr(v, pTab);
      sqlite3ExprExpireColumnCacheLines(pParse, regCols, regCols+pTab->nCol-1);
    }
    sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol);
    if( pParse->nErr ) goto update_cleanup;
    sqlite3VdbeAddOp3(v, OP_Insert, newIdx, regRow, regRowid);
    sqlite3ReleaseTempReg(pParse, regRowid);
    sqlite3ReleaseTempReg(pParse, regRow);

** 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 1.296 2008/03/31 23:48:05 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

**
** There should be nColumn values on the stack.  The index
** to be probed is pIdx.  Pop the values from the stack and
** replace them all with a single record that is the index
** problem.
*/
static void buildIndexProbe(
  Parse *pParse,  /* Parsing and code generation context */
  int nColumn,    /* The number of columns to check for NULL */
  Index *pIdx,    /* Index that we will be searching */
  int regSrc,     /* Take values from this register */
  int regDest     /* Write the result into this register */
){
  Vdbe *v = pParse->pVdbe;
  assert( regSrc>0 );
  assert( regDest>0 );
  assert( v!=0 );
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regSrc, nColumn, regDest);
  sqlite3IndexAffinityStr(v, pIdx);
  sqlite3ExprExpireColumnCacheLines(pParse, regSrc, regSrc+nColumn-1);
}


/*
** 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 
** coded.

      if( testOp!=OP_Noop || (isMinQuery&&bRev) ){
        int nCol = nEq + topLimit;
        if( isMinQuery && bRev && !topLimit ){
          sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nCol);
          nCol++;
          topEq = 0;
        }
        buildIndexProbe(pParse, nCol, pIdx, regBase, pLevel->iMem);
        if( bRev ){
          int op = topEq ? OP_MoveLe : OP_MoveLt;
          sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, pLevel->iMem);
        }
      }else if( bRev ){
        sqlite3VdbeAddOp2(v, OP_Last, iIdxCur, brk);
      }

        }
        if( bRev ){
          r1 = pLevel->iMem;
          testOp = OP_IdxLT;
        }else{
          r1 = sqlite3GetTempReg(pParse);
        }
        buildIndexProbe(pParse, nCol, pIdx, regBase, r1);
        if( !bRev ){
          int op = btmEq ? OP_MoveGe : OP_MoveGt;
          sqlite3VdbeAddOp3(v, op, iIdxCur, nxt, r1);
          sqlite3ReleaseTempReg(pParse, r1);
        }
      }else if( bRev ){
        testOp = OP_Noop;

      if( (obflag==ORDERBY_MIN)
       && (pLevel->flags&WHERE_ORDERBY) 
       && (pIdx->nColumn>nEq)
       && (pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq])
      ){
        isMinQuery = 1;
        buildIndexProbe(pParse, nEq, pIdx, regBase, pLevel->iMem);
        sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
        r1 = ++pParse->nMem;
        buildIndexProbe(pParse, nEq+1, pIdx, regBase, r1);
      }else{
        /* Generate a single key that will be used to both start and 
        ** terminate the search
        */
        r1 = pLevel->iMem;
        buildIndexProbe(pParse, nEq, pIdx, regBase, r1);
      }

      /* 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. */

    /* 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_Integer, 1, pLevel->iLeftJoin);
      VdbeComment((v, "record LEFT JOIN hit"));
      sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur);
      sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur);
      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, SQLITE_JUMPIFNULL);
        pTerm->flags |= TERM_CODED;
      }

  Vdbe *v = pWInfo->pParse->pVdbe;
  int i;
  WhereLevel *pLevel;
  SrcList *pTabList = pWInfo->pTabList;

  /* Generate loop termination code.
  */
  sqlite3ExprClearColumnCache(pWInfo->pParse, -1);
  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 ){