SQLite

**    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 1.338 2008/01/08 23:54:25 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

      if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
        Token *p = &pLeft->token;
        if( pLeft->op==TK_FLOAT ){
          codeReal(v, (char*)p->z, p->n, 1, target);
        }else{
          codeInteger(v, (char*)p->z, p->n, 1, target);
        }






        inReg = target;
        break;
      }
      /* 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, 0);
      sqlite3VdbeAddOp0(v, op);

      sqlite3VdbeAddOp0(v, OP_SCopy);
      j1 = sqlite3VdbeAddOp0(v, OP_NotNull);
      sqlite3VdbeAddOp1(v, OP_Pop, 2);
      sqlite3VdbeAddOp0(v, OP_Null);
      j2  = sqlite3VdbeAddOp0(v, OP_Goto);
      sqlite3VdbeJumpHere(v, j1);
      if( eType==IN_INDEX_ROWID ){
        j3 = sqlite3VdbeAddOp1(v, OP_MustBeInt, 1);
        j4 = sqlite3VdbeAddOp1(v, OP_NotExists, pExpr->iTable);
        j5 = sqlite3VdbeAddOp0(v, OP_Goto);
        sqlite3VdbeJumpHere(v, j3);
        sqlite3VdbeJumpHere(v, j4);
      }else{
        sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &affinity, 1);
        j5 = sqlite3VdbeAddOp1(v, OP_Found, pExpr->iTable);

        sqlite3ExprCode(pParse, aListelem[i].pExpr, 0);
        if( pExpr->pLeft ){
          sqlite3VdbeAddOp1(v, OP_SCopy, -1);
          jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
                                 OP_Ne, 0, 0, 0, SQLITE_JUMPIFNULL);
          sqlite3VdbeAddOp1(v, OP_Pop, 1);
        }else{
          jumpInst = sqlite3VdbeAddOp2(v, OP_IfNot, 1, 0);
        }
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr, target);
        sqlite3VdbeAddOp2(v, OP_Goto, 0, expr_end_label);
        sqlite3VdbeJumpHere(v, jumpInst);
      }
      if( pExpr->pLeft ){
        sqlite3VdbeAddOp2(v, OP_Pop, 1, 0);

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

/*
** Generate code for a boolean expression such that a jump is made

      sqlite3ExprCode(pParse, pRight, 0);
      codeCompare(pParse, pLeft, pRight, OP_Gt,
                  0, 0, dest, jumpIfNull);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr, 0);
      sqlite3VdbeAddOp2(v, OP_IfNot, jumpIfNull, dest);
      break;
    }
  }
}

/*
** Do a deep comparison of two expression trees.  Return TRUE (non-zero)

**    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 1.218 2008/01/08 23:54:25 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:

          sqlite3VdbeAddOp2(v, OP_Move, 0, regRowid);
        }
      }
      /* If the PRIMARY KEY expression is NULL, then use OP_NewRowid
      ** to generate a unique primary key value.
      */
      if( !appendFlag ){
        sqlite3VdbeAddOp2(v, OP_IfMemNull, regRowid, sqlite3VdbeCurrentAddr(v)+2);
        sqlite3VdbeAddOp2(v, OP_Goto, -1, sqlite3VdbeCurrentAddr(v)+2);
        sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
        sqlite3VdbeAddOp3(v, OP_MustBeInt, 0, 0, regRowid);
      }
    }else if( IsVirtual(pTab) ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regRowid);
    }else{
      sqlite3VdbeAddOp3(v, OP_NewRowid, baseCur, regRowid, regAutoinc);
      appendFlag = 1;
    }

/*
** 2003 April 6
**
** 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.
**
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.162 2008/01/07 19:20:25 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)

  ** database file.  The cache size is actually the absolute value of
  ** this memory location.  The sign of meta-value 2 determines the
  ** synchronous setting.  A negative value means synchronous is off
  ** and a positive value means synchronous is on.
  */
  if( sqlite3StrICmp(zLeft,"default_cache_size")==0 ){
    static const VdbeOpList getCacheSize[] = {
      { OP_ReadCookie,  0, 0,        2},  /* 0 */
      { OP_AbsValue,    0, 0,        0},
      { OP_Copy,        0, 0,        0},
      { OP_Integer,     0, 0,        0},

      { OP_Ne,          0, 6,        0},
      { OP_Integer,     0, 0,        0},  /* 5 */
      { 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);
      sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, 0, 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

  /*

      goto pragma_out;
    }
    if( zRight==0 || !sqlite3GetInt32(zRight, &iLimit) || iLimit<=0 ){
      iLimit = 0x7fffffff;
    }
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, iLimit, 1);
    addr = sqlite3VdbeAddOp2(v, OP_IncrVacuum, iDb, 0);
    sqlite3VdbeAddOp2(v, OP_Callback, 0, 0);
    sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
    sqlite3VdbeAddOp2(v, OP_IfMemPos, 1, addr);
    sqlite3VdbeJumpHere(v, addr);
  }else
#endif

#ifndef SQLITE_OMIT_PAGER_PRAGMAS
  /*
  **  PRAGMA [database.]cache_size

      HashElem *x;
      Hash *pTbls;
      int cnt = 0;

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

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp2(v, OP_IfMemPos, 1, 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)){

      */
      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, 1, 0);
        sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
        sqlite3VdbeJumpHere(v, addr);
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);
        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){

             { OP_AddImm,       1, -1,  0},
             { OP_String8,      0,  0,  0},  /* 8 */
             { 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, 1, 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);

**    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 1.70 2008/01/03 07:09:48 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

  }else{
    DbSetProperty(db, iDb, DB_Empty);
  }
  pDb->pSchema->enc = ENC(db);

  size = meta[2];
  if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; }

  pDb->pSchema->cache_size = size;
  sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);

  /*
  ** file_format==1    Version 3.0.0.
  ** file_format==2    Version 3.1.3.  // ALTER TABLE ADD COLUMN
  ** file_format==3    Version 3.1.4.  // ditto but with non-NULL defaults

**    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 1.393 2008/01/08 23:54:25 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, 0);
  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_AddImm, pSelect->iLimit+1, -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
*/
static void codeOffset(
  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_AddImm, p->iOffset, -1);
    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);
  }
}

    ** 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, 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_SCopy, iMem, 0);

#endif
  }

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

    }
  }

  /* Jump to the end of the loop when the LIMIT is reached
  */
  if( p->iLimit>=0 ){
    sqlite3VdbeAddOp2(v, OP_AddImm, p->iLimit, -1);
    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( p->pLimit ){
    p->iLimit = iLimit = ++pParse->nMem;
    pParse->nMem++;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pLimit, 0);
    sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp2(v, OP_Move, 0, iLimit);
    VdbeComment((v, "LIMIT counter"));
    sqlite3VdbeAddOp2(v, OP_IfMemZero, iLimit, iBreak);
    sqlite3VdbeAddOp2(v, OP_SCopy, iLimit, 0);
  }
  if( p->pOffset ){
    p->iOffset = iOffset = ++pParse->nMem;
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) return;
    sqlite3ExprCode(pParse, p->pOffset, 0);
    sqlite3VdbeAddOp2(v, OP_MustBeInt, 0, 0);
    sqlite3VdbeAddOp2(v, p->pLimit==0 ? OP_Move : OP_Copy, 0, iOffset);
    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_Integer, -1, iLimit+1);
    addr2 = sqlite3VdbeAddOp2(v, OP_Goto, 0, 0);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp2(v, OP_Move, 0, iLimit+1);
    VdbeComment((v, "LIMIT+OFFSET"));
    sqlite3VdbeJumpHere(v, addr2);
  }
}

        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;
        }

      ** order to signal the caller to abort.
      */
      addrSetAbort = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp2(v, OP_Integer, 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, SQLITE_JUMPIFNULL);
      }
      rc = selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,

      */
      sqlite3VdbeResolveLabel(v, addrGroupByChange);
      for(j=0; j<pGroupBy->nExpr; j++){
        sqlite3VdbeAddOp2(v, OP_Move, iBMem+j, iAMem+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
      */

**    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 1.164 2008/01/08 18:57:50 drh Exp $
*/
#include "sqliteInt.h"

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

    /* 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, regNewRowid);
      sqlite3VdbeAddOp3(v, OP_MustBeInt, 0, 0, regNewRowid);
    }

    /* Compute new data for this record.  
    */
    for(i=0; i<pTab->nCol; i++){
      if( i==pTab->iPKey ){
        sqlite3VdbeAddOp2(v, OP_Null, 0, regData+i);

**
** 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 1.689 2008/01/08 23:54:25 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor

*/
case OP_Real: {            /* same as TK_FLOAT, out2-prerelease */
  pOut->flags = MEM_Real;
  pOut->r = *pOp->p4.pReal;
  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, out2-prerelease */
  assert( pOp->p4.z!=0 );
  pOp->opcode = OP_String;

  assert( pOp->p1 <= SQLITE_MAX_LENGTH );
  sqlite3VdbeMemSetStr(pOut, pOp->p4.z, pOp->p1, 0, 0);
  pOut->enc = encoding;
  break;
}
#endif /* SQLITE_OMIT_BLOB_LITERAL */

/* Opcode: Variable P1 * *
**
** The value of variable P1 is written into register P2 or pushed
** onto the stack if P2 is zero.  A variable is
** an unknown in the original SQL string as handed to sqlite3_compile().
** Any occurance of the '?' character in the original SQL is considered
** a variable.  Variables in the SQL string are number from left to
** right beginning with 1.  The values of variables are set using the

  if( sqlite3VdbeMemTooBig(pVar) ){
    goto too_big;
  }
  sqlite3VdbeMemShallowCopy(pOut, &p->aVar[j], MEM_Static);
  break;
}

/* Opcode: Pop P1 * *
**
** P1 elements are popped off of the top of stack and discarded.
*/
case OP_Pop: {            /* no-push */
  assert( pOp->p1>=0 );
  popStack(&pTos, pOp->p1);
  assert( pTos>=&p->aStack[-1] );

  pOut->flags = MEM_Str|MEM_Dyn|MEM_Term;
  pOut->xDel = 0;
  pOut->enc = encoding;
  pOut->z = zNew;
  break;
}

/* Opcode: Add * * *
**
** Pop the top two elements from the stack, add them together,
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the addition.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Multiply * * *
**

** Pop the top two elements from the stack, multiply them together,
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the multiplication.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Subtract * * *
**
** Pop the top two elements from the stack, subtract the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the subtraction.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Divide * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the result back onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the division.  Division by zero returns NULL.
** If either operand is NULL, the result is NULL.
*/
/* Opcode: Remainder * * *
**
** Pop the top two elements from the stack, divide the
** first (what was on top of the stack) from the second (the
** next on stack)
** and push the remainder after division onto the stack.  If either element
** is a string then it is converted to a double using the atof()
** function before the division.  Division by zero returns NULL.

** If either operand is NULL, the result is NULL.
*/
case OP_Add:                   /* same as TK_PLUS, in1, in2, out3 */
case OP_Subtract:              /* same as TK_MINUS, in1, in2, out3 */
case OP_Multiply:              /* same as TK_STAR, in1, in2, out3 */
case OP_Divide:                /* same as TK_SLASH, in1, in2, out3 */
case OP_Remainder: {           /* same as TK_REM, in1, in2, out3 */

  pIn1->u.i = v;
  pIn1->flags = MEM_Int;
  break;
}

/* Opcode: MustBeInt P1 P2 P3
** 

** Force the top of the stack to be an integer.  If the top of the
** stack is not an integer and cannot be converted into an integer
** without data loss, then jump immediately to P2, or if P2==0
** raise an SQLITE_MISMATCH exception.
**
** If the top of the stack is not an integer and P2 is not zero and
** P1 is 1, then the stack is popped.  In all other cases, the depth
** of the stack is unchanged.
**
** If P3 is not zero, then act on the value in register P3 instead
** of using the stack.
*/
case OP_MustBeInt: {            /* no-push, jump */
  Mem *pMem = ((pOp->p3==0)?pTos:&p->aMem[pOp->p3]);
  assert( pOp->p3 || pTos>=p->aStack );
  assert( pOp->p3>=0 && pOp->p3<=p->nMem );
  REGISTER_TRACE(pOp->p3, pMem);
  applyAffinity(pMem, SQLITE_AFF_NUMERIC, encoding);
  if( (pMem->flags & MEM_Int)==0 ){
    if( pOp->p2==0 ){
      rc = SQLITE_MISMATCH;
      goto abort_due_to_error;
    }else if( pMem==pTos ){

      if( pOp->p1 ) popStack(&pTos, 1);

      pc = pOp->p2 - 1;
    }
  }else{
    Release(pMem);
    pMem->flags = MEM_Int;
  }
  break;
}

/* Opcode: RealAffinity P1 * * * *
**
** If register P1 holds an integer convert it to a real value.

  }else{
    pOut->u.i = v1;
    pOut->flags = MEM_Int;
  }
  break;
}

/* Opcode: Negative * * *
**
** Treat the top of the stack as a numeric quantity.  Replace it
** with its additive inverse.  If the top of the stack is NULL
** its value is unchanged.
*/
/* Opcode: AbsValue * * *
**
** Treat the top of the stack as a numeric quantity.  Replace it
** with its absolute value. If the top of the stack is NULL
** its value is unchanged.
*/
case OP_Negative:              /* same as TK_UMINUS, no-push */
case OP_AbsValue: {
  assert( pTos>=p->aStack );
  if( (pTos->flags & (MEM_Real|MEM_Int|MEM_Null))==0 ){
    sqlite3VdbeMemNumerify(pTos);
  }
  if( pTos->flags & MEM_Real ){
    Release(pTos);
    if( pOp->opcode==OP_Negative || pTos->r<0.0 ){
      pTos->r = -pTos->r;
    }
    pTos->flags = MEM_Real;
  }else if( pTos->flags & MEM_Int ){
    Release(pTos);
    if( pOp->opcode==OP_Negative || pTos->u.i<0 ){
      pTos->u.i = -pTos->u.i;
    }
    pTos->flags = MEM_Int;
  }
  break;
}

/* Opcode: Not * * *
**
** Interpret the top of the stack as a boolean value.  Replace it
** with its complement.  If the top of the stack is NULL its value
** is unchanged.
*/
case OP_Not: {                /* same as TK_NOT, no-push */
  assert( pTos>=p->aStack );

  if( pTos->flags & MEM_Null ) break;  /* Do nothing to NULLs */
  sqlite3VdbeMemIntegerify(pTos);
  assert( (pTos->flags & MEM_Dyn)==0 );
  pTos->u.i = !pTos->u.i;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: BitNot * * *
**
** Interpret the top of the stack as an value.  Replace it
** with its ones-complement.  If the top of the stack is NULL its
** value is unchanged.
*/
case OP_BitNot: {             /* same as TK_BITNOT, no-push */
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ) break;  /* Do nothing to NULLs */
  sqlite3VdbeMemIntegerify(pTos);
  assert( (pTos->flags & MEM_Dyn)==0 );
  pTos->u.i = ~pTos->u.i;
  pTos->flags = MEM_Int;
  break;
}

/* Opcode: Noop * * *
**
** Do nothing.  This instruction is often useful as a jump
** destination.
*/
/*
** The magic Explain opcode are only inserted when explain==2 (which
** is to say when the EXPLAIN QUERY PLAN syntax is used.)
** This opcode records information from the optimizer.  It is the
** the same as a no-op.  This opcodesnever appears in a real VM program.
*/
case OP_Explain:
case OP_Noop: {            /* no-push */
  break;
}

/* Opcode: If P1 P2 *
**

** Pop a single boolean from the stack.  If the boolean popped is
** true, then jump to p2.  Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise.  A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
/* Opcode: IfNot P1 P2 *
**
** Pop a single boolean from the stack.  If the boolean popped is
** false, then jump to p2.  Otherwise continue to the next instruction.
** An integer is false if zero and true otherwise.  A string is
** false if it has zero length and true otherwise.
**
** If the value popped of the stack is NULL, then take the jump if P1
** is true and fall through if P1 is false.
*/
case OP_If:                 /* no-push, jump */
case OP_IfNot: {            /* no-push, jump */
  int c;
  assert( pTos>=p->aStack );
  if( pTos->flags & MEM_Null ){
    c = pOp->p1;
  }else{
#ifdef SQLITE_OMIT_FLOATING_POINT
    c = sqlite3VdbeIntValue(pTos);
#else
    c = sqlite3VdbeRealValue(pTos)!=0.0;
#endif
    if( pOp->opcode==OP_IfNot ) c = !c;
  }
  Release(pTos);
  pTos--;
  if( c ) pc = pOp->p2-1;

  break;
}

/* Opcode: StackIsNull P1 P2 *
**
** Check the top of the stack and jump to P2 if the top of the stack
** is NULL.  If P1 is positive, then pop P1 elements from the stack

  if( pMem->u.i<pNew->u.i){
    pMem->u.i = pNew->u.i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: IfMemPos P1 P2 *
**
** If the value of memory cell P1 is 1 or greater, jump to P2.
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemPos: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i>0 ){
     pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IfMemNeg P1 P2 *
**
** If the value of memory cell P1 is less than zero, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemNeg: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i<0 ){
     pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IfMemZero P1 P2 *
**
** If the value of memory cell P1 is exactly 0, jump to P2. 
**
** It is illegal to use this instruction on a memory cell that does
** not contain an integer.  An assertion fault will result if you try.
*/
case OP_IfMemZero: {        /* no-push, jump */
  int i = pOp->p1;
  Mem *pMem;
  assert( i>0 && i<=p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->u.i==0 ){
     pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: IfMemNull P1 P2 *
**
** If the value of memory cell P1 is NULL, jump to P2. 
*/
case OP_IfMemNull: {        /* no-push, jump */
  int i = pOp->p1;
  assert( i>0 && i<=p->nMem );
  if( p->aMem[i].flags & MEM_Null ){
     pc = pOp->p2 - 1;
  }
  break;
}

/* Opcode: AggStep P1 P2 P4
**

** 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 1.278 2008/01/08 23:54:26 drh Exp $
*/
#include "sqliteInt.h"

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

      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;

        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.
  */
  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);

  /* Close all of the cursors that were opened by sqlite3WhereBegin.
  */
  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