SQLite

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.530 2009/04/23 13:22:43 drh Exp $
*/
#include "sqliteInt.h"

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

  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 && !db->mallocFailed ){
#ifdef SQLITE_DEBUG
    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
    sqlite3VdbeTrace(v, trace);
#endif
    assert( pParse->iCacheLevel==0 );  /* Disables and re-enables match */
    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->nMem,
                         pParse->nTab, pParse->explain);
    pParse->rc = SQLITE_DONE;
    pParse->colNamesSet = 0;
  }else if( pParse->rc==SQLITE_OK ){
    pParse->rc = SQLITE_ERROR;
  }

**    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 1.428 2009/04/23 13:22:43 drh Exp $
*/
#include "sqliteInt.h"

/*
** Return the 'affinity' of the expression pExpr if any.
**
** If pExpr is a column, a reference to a column via an 'AS' alias,

  Expr *pExpr, 
  int rMayHaveNull,
  int isRowid
){
  int testAddr = 0;                       /* One-time test address */
  Vdbe *v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  sqlite3ExprCachePush(pParse);

  /* This code must be run in its entirety every time it is encountered
  ** if any of the following is true:
  **
  **    *  The right-hand side is a correlated subquery
  **    *  The right-hand side is an expression list containing variables
  **    *  We are inside a trigger

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

          /* Evaluate the expression and insert it into the temp table */

          r3 = sqlite3ExprCodeTarget(pParse, pE2, r1);



          if( isRowid ){
            sqlite3VdbeAddOp2(v, OP_MustBeInt, r3, sqlite3VdbeCurrentAddr(v)+2);
            sqlite3VdbeAddOp3(v, OP_Insert, pExpr->iTable, r2, r3);
          }else{
            sqlite3VdbeAddOp4(v, OP_MakeRecord, r3, 1, r2, &affinity, 1);
            sqlite3ExprCacheAffinityChange(pParse, r3, 1);
            sqlite3VdbeAddOp2(v, OP_IdxInsert, pExpr->iTable, r2);

      break;
    }
  }

  if( testAddr ){
    sqlite3VdbeJumpHere(v, testAddr-1);
  }
  sqlite3ExprCachePop(pParse, 1);

  return;
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*
** Duplicate an 8-byte value

      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
    }else{
      codeReal(v, z, n, negFlag, iMem);
    }
  }
}

/*
** Clear a cache entry.
*/
static void cacheEntryClear(Parse *pParse, struct yColCache *p){
  if( p->tempReg ){
    if( pParse->nTempReg<ArraySize(pParse->aTempReg) ){
      pParse->aTempReg[pParse->nTempReg++] = p->iReg;
    }
    p->tempReg = 0;
  }
}


/*
** Record in the column cache that a particular column from a
** particular table is stored in a particular register.
*/
void sqlite3ExprCacheStore(Parse *pParse, int iTab, int iCol, int iReg){
  int i;
  int minLru;
  int idxLru;
  struct yColCache *p;

  /* First replace any existing entry */
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg && p->iTable==iTab && p->iColumn==iCol ){
      cacheEntryClear(pParse, p);
      p->iLevel = pParse->iCacheLevel;
      p->iReg = iReg;
      p->affChange = 0;
      p->lru = pParse->iCacheCnt++;
      return;
    }
  }
  if( iReg<=0 ) return;

  /* Find an empty slot and replace it */
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg==0 ){
      p->iLevel = pParse->iCacheLevel;
      p->iTable = iTab;
      p->iColumn = iCol;
      p->iReg = iReg;
      p->affChange = 0;
      p->tempReg = 0;
      p->lru = pParse->iCacheCnt++;
      return;
    }
  }

  /* Replace the last recently used */
  minLru = 0x7fffffff;
  idxLru = -1;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->lru<minLru ){
      idxLru = i;
      minLru = p->lru;
    }
  }
  if( idxLru>=0 ){
    p = &pParse->aColCache[idxLru];
    p->iLevel = pParse->iCacheLevel;
    p->iTable = iTab;
    p->iColumn = iCol;
    p->iReg = iReg;
    p->affChange = 0;
    p->tempReg = 0;
    p->lru = pParse->iCacheCnt++;
    return;
  }
}

/*
** Indicate that a register is being overwritten.  Purge the register
** from the column cache.
*/
void sqlite3ExprCacheRemove(Parse *pParse, int iReg){
  int i;
  struct yColCache *p;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg==iReg ){
      cacheEntryClear(pParse, p);
      p->iReg = 0;
    }
  }
}

/*
** Remember the current column cache context.  Any new entries added
** added to the column cache after this call are removed when the
** corresponding pop occurs.
*/
void sqlite3ExprCachePush(Parse *pParse){
  pParse->iCacheLevel++;
}

/*
** Remove from the column cache any entries that were added since the
** the previous N Push operations.  In other words, restore the cache
** to the state it was in N Pushes ago.
*/
void sqlite3ExprCachePop(Parse *pParse, int N){
  int i;
  struct yColCache *p;
  assert( N>0 );
  assert( pParse->iCacheLevel>=N );
  pParse->iCacheLevel -= N;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg && p->iLevel>pParse->iCacheLevel ){
      cacheEntryClear(pParse, p);
      p->iReg = 0;
    }
  }
}

/*
** 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.
**

  int iReg,        /* Store results here */
  int allowAffChng /* True if prior affinity changes are OK */
){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct yColCache *p;

  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg>0 && p->iTable==iTable && p->iColumn==iColumn
           && (!p->affChange || allowAffChng) ){
#if 0
      sqlite3VdbeAddOp0(v, OP_Noop);
      VdbeComment((v, "OPT: tab%d.col%d -> r%d", iTable, iColumn, p->iReg));
#endif
      p->lru = pParse->iCacheCnt++;
      p->tempReg = 0;  /* This pins the register, but also leaks it */
      return p->iReg;
    }
  }  
  assert( v!=0 );
  if( iColumn<0 ){
    sqlite3VdbeAddOp2(v, OP_Rowid, 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
  }



  sqlite3ExprCacheStore(pParse, iTable, iColumn, iReg);








  return iReg;
}

/*
** Clear all column cache entries.

*/
void sqlite3ExprCacheClear(Parse *pParse){




  int i;




  struct yColCache *p;

  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    if( p->iReg ){
      cacheEntryClear(pParse, p);
      p->iReg = 0;
    }
  }
}

/*
** Record the fact that an affinity change has occurred on iCount
** registers starting with iStart.
*/
void sqlite3ExprCacheAffinityChange(Parse *pParse, int iStart, int iCount){
  int iEnd = iStart + iCount - 1;
  int i;
  struct yColCache *p;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    int r = p->iReg;
    if( r>=iStart && r<=iEnd ){
      p->affChange = 1;
    }
  }
}

/*
** Generate code to move content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1. Keep the column cache up-to-date.
*/
void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
  int i;
  struct yColCache *p;
  if( iFrom==iTo ) return;
  sqlite3VdbeAddOp3(pParse->pVdbe, OP_Move, iFrom, iTo, nReg);
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    int x = p->iReg;
    if( x>=iFrom && x<iFrom+nReg ){
      p->iReg += iTo-iFrom;
    }
  }
}

/*
** Generate code to copy content from registers iFrom...iFrom+nReg-1
** over to iTo..iTo+nReg-1.

/*
** 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;
  struct yColCache *p;
  for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
    int r = p->iReg;
    if( r>=iFrom && r<=iTo ) return 1;
  }
  return 0;
}




















/*
** If the last instruction coded is an ephemeral copy of any of
** the registers in the nReg registers beginning with iReg, then
** convert the last instruction from OP_SCopy to OP_Copy.
*/
void sqlite3ExprHardCopy(Parse *pParse, int iReg, int nReg){
  int addr;

** of 1 to pParse->nAlias inclusive.  
**
** pParse->aAlias[iAlias-1] records the register number where the value
** of the iAlias-th alias is stored.  If zero, that means that the
** alias has not yet been computed.
*/
static int codeAlias(Parse *pParse, int iAlias, Expr *pExpr, int target){
#if 0
  sqlite3 *db = pParse->db;
  int iReg;
  if( pParse->nAliasAlloc<pParse->nAlias ){
    pParse->aAlias = sqlite3DbReallocOrFree(db, pParse->aAlias,
                                 sizeof(pParse->aAlias[0])*pParse->nAlias );
    testcase( db->mallocFailed && pParse->nAliasAlloc>0 );
    if( db->mallocFailed ) return 0;
    memset(&pParse->aAlias[pParse->nAliasAlloc], 0,
           (pParse->nAlias-pParse->nAliasAlloc)*sizeof(pParse->aAlias[0]));
    pParse->nAliasAlloc = pParse->nAlias;
  }
  assert( iAlias>0 && iAlias<=pParse->nAlias );
  iReg = pParse->aAlias[iAlias-1];
  if( iReg==0 ){
    if( pParse->iCacheLevel>0 ){
      iReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
    }else{
      iReg = ++pParse->nMem;
      sqlite3ExprCode(pParse, pExpr, iReg);
      pParse->aAlias[iAlias-1] = iReg;
    }
  }
  return iReg;
#else
  return sqlite3ExprCodeTarget(pParse, pExpr, target);
#endif
}

/*
** 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.
**

      */
      affinity = comparisonAffinity(pExpr);


      /* Code the <expr> from "<expr> IN (...)". The temporary table
      ** pExpr->iTable contains the values that make up the (...) set.
      */
      sqlite3ExprCachePush(pParse);
      sqlite3ExprCode(pParse, pExpr->pLeft, target);

      j2 = sqlite3VdbeAddOp1(v, OP_IsNull, target);
      if( eType==IN_INDEX_ROWID ){
        j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, target);
        j4 = sqlite3VdbeAddOp3(v, OP_NotExists, pExpr->iTable, 0, target);
        sqlite3VdbeAddOp2(v, OP_Integer, 1, target);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);

          ** expression.
          */
          sqlite3VdbeAddOp2(v, OP_Copy, rNotFound, target);
        }
      }
      sqlite3VdbeJumpHere(v, j2);
      sqlite3VdbeJumpHere(v, j5);
      sqlite3ExprCachePop(pParse, 1);
      VdbeComment((v, "end IN expr r%d", target));
      break;
    }
#endif
    /*
    **    x BETWEEN y AND z
    **

      int i;                            /* Loop counter */
      ExprList *pEList;                 /* List of WHEN terms */
      struct ExprList_item *aListelem;  /* Array of WHEN terms */
      Expr opCompare;                   /* The X==Ei expression */
      Expr cacheX;                      /* Cached expression X */
      Expr *pX;                         /* The X expression */
      Expr *pTest = 0;                  /* X==Ei (form A) or just Ei (form B) */
      VVA_ONLY( int iCacheLevel = pParse->iCacheLevel; )

      assert( !ExprHasProperty(pExpr, EP_xIsSelect) && pExpr->x.pList );
      assert((pExpr->x.pList->nExpr % 2) == 0);
      assert(pExpr->x.pList->nExpr > 0);
      pEList = pExpr->x.pList;
      aListelem = pEList->a;
      nExpr = pEList->nExpr;
      endLabel = sqlite3VdbeMakeLabel(v);
      if( (pX = pExpr->pLeft)!=0 ){
        cacheX = *pX;
        testcase( pX->op==TK_COLUMN || pX->op==TK_REGISTER );
        cacheX.iTable = sqlite3ExprCodeTemp(pParse, pX, &regFree1);
        testcase( regFree1==0 );
        cacheX.op = TK_REGISTER;
        opCompare.op = TK_EQ;
        opCompare.pLeft = &cacheX;
        pTest = &opCompare;
      }

      for(i=0; i<nExpr; i=i+2){
        sqlite3ExprCachePush(pParse);
        if( pX ){
          assert( pTest!=0 );
          opCompare.pRight = aListelem[i].pExpr;
        }else{
          pTest = aListelem[i].pExpr;
        }
        nextCase = sqlite3VdbeMakeLabel(v);
        testcase( pTest->op==TK_COLUMN || pTest->op==TK_REGISTER );
        sqlite3ExprIfFalse(pParse, pTest, nextCase, SQLITE_JUMPIFNULL);
        testcase( aListelem[i+1].pExpr->op==TK_COLUMN );
        testcase( aListelem[i+1].pExpr->op==TK_REGISTER );
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, endLabel);
        sqlite3ExprCachePop(pParse, 1);
        sqlite3VdbeResolveLabel(v, nextCase);
      }
      if( pExpr->pRight ){
        sqlite3ExprCachePush(pParse);
        sqlite3ExprCode(pParse, pExpr->pRight, target);
        sqlite3ExprCachePop(pParse, 1);
      }else{
        sqlite3VdbeAddOp2(v, OP_Null, 0, target);
      }
      assert( pParse->iCacheLevel==iCacheLevel );
      sqlite3VdbeResolveLabel(v, endLabel);


      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);
      testcase( jumpIfNull==0 );
      sqlite3ExprCachePush(pParse);
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2,jumpIfNull^SQLITE_JUMPIFNULL);

      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);


      sqlite3VdbeResolveLabel(v, d2);
      sqlite3ExprCachePop(pParse, 1);
      break;
    }
    case TK_OR: {
      testcase( jumpIfNull==0 );

      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);

      sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);


      break;
    }
    case TK_NOT: {
      testcase( jumpIfNull==0 );
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }

  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: {
      testcase( jumpIfNull==0 );

      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);

      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);


      break;
    }
    case TK_OR: {
      int d2 = sqlite3VdbeMakeLabel(v);
      testcase( jumpIfNull==0 );
      sqlite3ExprCachePush(pParse);
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, jumpIfNull^SQLITE_JUMPIFNULL);

      sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);


      sqlite3VdbeResolveLabel(v, d2);
      sqlite3ExprCachePop(pParse, 1);
      break;
    }
    case TK_NOT: {
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_LT:

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

/*
** Allocate a single new register for use to hold some intermediate result.
*/
int sqlite3GetTempReg(Parse *pParse){
  if( pParse->nTempReg==0 ){
    return ++pParse->nMem;
  }
  return pParse->aTempReg[--pParse->nTempReg];
}

/*
** Deallocate a register, making available for reuse for some other
** purpose.
**
** If a register is currently being used by the column cache, then
** the dallocation is deferred until the column cache line that uses
** the register becomes stale.
*/
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
  if( iReg && pParse->nTempReg<ArraySize(pParse->aTempReg) ){
    int i;
    struct yColCache *p;
    for(i=0, p=pParse->aColCache; i<SQLITE_N_COLCACHE; i++, p++){
      if( p->iReg==iReg ){
        p->tempReg = 1;
        return;
      }
    }
    pParse->aTempReg[pParse->nTempReg++] = iReg;
  }
}

/*
** Allocate or deallocate a block of nReg consecutive registers
*/

**    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 1.509 2009/04/23 13:22:43 drh Exp $
*/
#include "sqliteInt.h"


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

  Select *pSelect,       /* The whole SELECT statement */
  int regData            /* Register holding data to be sorted */
){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCacheClear(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1);
  sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);

    for(i=0; i<nColumn; i++){
      sqlite3VdbeAddOp3(v, OP_Column, srcTab, i, regResult+i);
    }
  }else if( eDest!=SRT_Exists ){
    /* If the destination is an EXISTS(...) expression, the actual
    ** values returned by the SELECT are not required.
    */
    sqlite3ExprCacheClear(pParse);
    sqlite3ExprCodeExprList(pParse, pEList, regResult, eDest==SRT_Output);
  }
  nColumn = nResultCol;

  /* If the DISTINCT keyword was present on the SELECT statement
  ** and this row has been seen before, then do not make this row
  ** part of the result.

  /* 
  ** "LIMIT -1" always shows all rows.  There is some
  ** contraversy about what the correct behavior should be.
  ** The current implementation interprets "LIMIT 0" to mean
  ** no rows.
  */
  sqlite3ExprCacheClear(pParse);
  if( p->pLimit ){
    p->iLimit = iLimit = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pLimit, iLimit);
    sqlite3VdbeAddOp1(v, OP_MustBeInt, iLimit);
    VdbeComment((v, "LIMIT counter"));

static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pF;
  struct AggInfo_col *pC;

  pAggInfo->directMode = 1;
  sqlite3ExprCacheClear(pParse);
  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    int nArg;
    int addrNext = 0;
    int regAgg;
    ExprList *pList = pF->pExpr->x.pList;
    assert( !ExprHasProperty(pF->pExpr, EP_xIsSelect) );
    if( pList ){

    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
                      (void*)pF->pFunc, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, (u8)nArg);
    sqlite3ReleaseTempRange(pParse, regAgg, nArg);
    sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg);
    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
      sqlite3ExprCacheClear(pParse);
    }
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
  }
  pAggInfo->directMode = 0;
  sqlite3ExprCacheClear(pParse);
}

/*
** Generate code for the SELECT statement given in the p argument.  
**
** The results are distributed in various ways depending on the
** contents of the SelectDest structure pointed to by argument pDest

        for(i=0; i<sAggInfo.nColumn; i++){
          if( sAggInfo.aCol[i].iSorterColumn>=j ){
            nCol++;
            j++;
          }
        }
        regBase = sqlite3GetTempRange(pParse, nCol);
        sqlite3ExprCacheClear(pParse);
        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase, 0);
        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;

        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
        sqlite3ExprCacheClear(pParse);
      }

      /* 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);
      sqlite3ExprCacheClear(pParse);
      for(j=0; j<pGroupBy->nExpr; j++){
        if( groupBySort ){
          sqlite3VdbeAddOp3(v, OP_Column, sAggInfo.sortingIdx, j, iBMem+j);
        }else{
          sAggInfo.directMode = 1;
          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr, iBMem+j);
        }

/*
** 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 1.860 2009/04/23 13:22:44 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

  u8 eDest;         /* How to dispose of the results */
  u8 affinity;      /* Affinity used when eDest==SRT_Set */
  int iParm;        /* A parameter used by the eDest disposal method */
  int iMem;         /* Base register where results are written */
  int nMem;         /* Number of registers allocated */
};

/*
** Size of the column cache
*/
#ifndef SQLITE_N_COLCACHE
# define SQLITE_N_COLCACHE 10
#endif

/*
** An SQL parser context.  A copy of this structure is passed through
** the parser and down into all the parser action routine in order to
** carry around information that is global to the entire parse.
**
** The structure is divided into two parts.  When the parser and code
** generate call themselves recursively, the first part of the structure

  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 iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
  int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
  u8 nColCache;        /* Number of entries in the column cache */
  u8 iColCache;        /* Next entry of the cache to replace */
  struct yColCache {
    int iTable;           /* Table cursor number */
    int iColumn;          /* Table column number */
    u8 affChange;         /* True if this register has had an affinity change */
    u8 tempReg;           /* iReg is a temp register that needs to be freed */
    int iLevel;           /* Nesting level */
    int iReg;             /* Reg with value of this column. 0 means none. */
    int lru;              /* Least recently used entry has the smallest value */
  } aColCache[SQLITE_N_COLCACHE];  /* One for each 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 */

void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**, u8, int);
void sqlite3WhereEnd(WhereInfo*);
int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, int);
void sqlite3ExprCodeMove(Parse*, int, int, int);
void sqlite3ExprCodeCopy(Parse*, int, int, int);
void sqlite3ExprCacheStore(Parse*, int, int, int);
void sqlite3ExprCachePush(Parse*);
void sqlite3ExprCachePop(Parse*, int);
void sqlite3ExprCacheRemove(Parse*, int);
void sqlite3ExprCacheClear(Parse*);
void sqlite3ExprCacheAffinityChange(Parse*, int, int);
void sqlite3ExprHardCopy(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, int);

/*
**
** 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.
**
*************************************************************************
**
**
** $Id: trigger.c,v 1.136 2009/04/23 13:22:44 drh Exp $
*/
#include "sqliteInt.h"

#ifndef SQLITE_OMIT_TRIGGER
/*
** Delete a linked list of TriggerStep structures.
*/

  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 ){
    sqlite3ExprCacheClear(pParse);
    orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
    pParse->trigStack->orconf = orconf;
    switch( pTriggerStep->op ){
      case TK_SELECT: {
        Select *ss = sqlite3SelectDup(db, pTriggerStep->pSelect, 0);
        if( ss ){
          SelectDest dest;

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is responsible 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 1.388 2009/04/23 13:22:44 drh Exp $
*/
#include "sqliteInt.h"

/*
** Trace output macros
*/
#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)

    int nConstraint = pVtabIdx->nConstraint;
    struct sqlite3_index_constraint_usage *aUsage =
                                                pVtabIdx->aConstraintUsage;
    const struct sqlite3_index_constraint *aConstraint =
                                                pVtabIdx->aConstraint;

    iReg = sqlite3GetTempRange(pParse, nConstraint+2);

    for(j=1; j<=nConstraint; j++){
      for(k=0; k<nConstraint; k++){
        if( aUsage[k].argvIndex==j ){
          int iTerm = aConstraint[k].iTermOffset;

          sqlite3ExprCode(pParse, pWC->a[iTerm].pExpr->pRight, iReg+j+1);
          break;
        }
      }
      if( k==nConstraint ) break;
    }


    sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
    sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pVtabIdx->idxStr,
                      pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
    pVtabIdx->needToFreeIdxStr = 0;
    for(j=0; j<nConstraint; j++){
      if( aUsage[j].omit ){

    assert( pTerm->pExpr!=0 );
    assert( pTerm->leftCursor==iCur );
    assert( omitTable==0 );
    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, iReleaseReg);
    addrNxt = pLevel->addrNxt;
    sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt);
    sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
    sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
    VdbeComment((v, "pk"));
    pLevel->op = OP_Noop;
  }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){
    /* Case 2:  We have an inequality comparison against the ROWID field.
    */
    int testOp = OP_Noop;
    int start;

    pLevel->op = bRev ? OP_Prev : OP_Next;
    pLevel->p1 = iCur;
    pLevel->p2 = start;
    pLevel->p5 = (pStart==0 && pEnd==0) ?1:0;
    if( testOp!=OP_Noop ){
      iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
      sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
      sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
    }
  }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
    /* Case 3: A scan using an index.
    **
    **         The WHERE clause may contain zero or more equality 

    startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
    endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
    start_constraints = pRangeStart || nEq>0;

    /* Seek the index cursor to the start of the range. */
    nConstraint = nEq;
    if( pRangeStart ){




      sqlite3ExprCode(pParse, pRangeStart->pExpr->pRight, regBase+nEq);

      sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
      nConstraint++;
    }else if( isMinQuery ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
      nConstraint++;
      startEq = 0;
      start_constraints = 1;

                      SQLITE_INT_TO_PTR(nConstraint), P4_INT32);

    /* Load the value for the inequality constraint at the end of the
    ** range (if any).
    */
    nConstraint = nEq;
    if( pRangeEnd ){
      sqlite3ExprCacheRemove(pParse, regBase+nEq);
      sqlite3ExprCode(pParse, pRangeEnd->pExpr->pRight, regBase+nEq);
      sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
      codeApplyAffinity(pParse, regBase, nEq+1, pIdx);
      nConstraint++;
    }

    /* Top of the loop body */

    /* Seek the table cursor, if required */
    disableTerm(pLevel, pRangeStart);
    disableTerm(pLevel, pRangeEnd);
    if( !omitTable ){
      iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg);
      sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
      sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg);  /* Deferred seek */
    }

    /* Record the instruction used to terminate the loop. Disable 
    ** WHERE clause terms made redundant by the index range scan.
    */
    pLevel->op = bRev ? OP_Prev : OP_Next;

    if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
    if( (pTerm->prereqAll & notReady)!=0 ) continue;
    pE = pTerm->pExpr;
    assert( pE!=0 );
    if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
      continue;
    }

    sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);

    k = 1;
    pTerm->wtFlags |= TERM_CODED;
  }

  /* 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->addrFirst = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
    VdbeComment((v, "record LEFT JOIN hit"));
    sqlite3ExprCacheClear(pParse);

    for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
      testcase( pTerm->wtFlags & TERM_VIRTUAL );
      testcase( pTerm->wtFlags & TERM_CODED );
      if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
      if( (pTerm->prereqAll & notReady)!=0 ) continue;
      assert( pTerm->pExpr );
      sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);

  int i;
  WhereLevel *pLevel;
  SrcList *pTabList = pWInfo->pTabList;
  sqlite3 *db = pParse->db;

  /* Generate loop termination code.
  */
  sqlite3ExprCacheClear(pParse);
  for(i=pTabList->nSrc-1; i>=0; i--){
    pLevel = &pWInfo->a[i];
    sqlite3VdbeResolveLabel(v, pLevel->addrCont);
    if( pLevel->op!=OP_Noop ){
      sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
      sqlite3VdbeChangeP5(v, pLevel->p5);
    }

#
#***********************************************************************
#
# This file implements regression tests for SQLite library.  The
# focus of this script is correct code generation of aliased result-set
# values.  See ticket #3343.
#
# $Id: alias.test,v 1.3 2009/04/23 13:22:44 drh Exp $
#
set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Aliases are currently evaluated twice.  We might try to change this
# in the future.  But not now.
return

# A procedure to return a sequence of increasing integers.
#
namespace eval ::seq {
  variable counter 0
  proc value {args} {
    variable counter

#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests to verify that ticket #3461 has been
# fixed.  
#
# $Id: tkt3461.test,v 1.3 2009/04/23 13:22:44 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

####################################
####################################
# REMOVE THESE TWO LINES:

do_test tkt3461-3.1 {
  execsql {
    CREATE TABLE t2(c, d);
    INSERT INTO t2 VALUES(3, 4);
  }
  # execsql { PRAGMA vdbe_trace = 1; PRAGMA vdbe_listing=1 }
breakpoint
  execsql { 
    SELECT a, b+1 AS b_plus_one, c, d 
    FROM t1 LEFT JOIN t2 
    ON (a=c AND d=b_plus_one)
  }
} {1 3 {} {}}

finish_test