SQLite

/*
** 2005 July 8
**
** 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 associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.8 2005/09/10 22:40:54 drh Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

    **    mem[iMem+nCol+1]       Last observed value of column 1
    **    ...
    **    mem[iMem+nCol+nCol]:   Last observed value of column N
    **
    ** Cells iMem through iMem+nCol are initialized to 0.  The others
    ** are initialized to NULL.
    */
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    for(i=0; i<=nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemStore, iMem+i, i==nCol);
    }
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    for(i=0; i<nCol; i++){
      sqlite3VdbeAddOp(v, OP_MemStore, iMem+nCol+i+1, i==nCol-1);
    }

    /* Do the analysis.
    */
    endOfLoop = sqlite3VdbeMakeLabel(v);
    sqlite3VdbeAddOp(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite3VdbeCurrentAddr(v);

        sqlite3VdbeAddOp(v, OP_Concat, nCol*2-1, 0);
      }else{
        sqlite3VdbeAddOp(v, OP_Dup, 1, 0);
      }
    }
    sqlite3VdbeOp3(v, OP_MakeRecord, 3, 0, "ttt", 0);
    sqlite3VdbeAddOp(v, OP_Insert, iStatCur, 0);
    sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
  }
}

/*
** Generate code that will cause the most recent index analysis to
** be laoded into internal hash tables where is can be used.
*/

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.350 2005/09/16 02:48:02 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeChangeP2(v, pParse->cookieGoto-1, sqlite3VdbeCurrentAddr(v));
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeAddOp(v, OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp(v, OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }
      sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->cookieGoto);
    }

    sqlite3VdbeAddOp(v, OP_IsUnique, iIdx, addr2);
    sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, OE_Abort,
                    "indexed columns are not unique", P3_STATIC);
    assert( addr2==sqlite3VdbeCurrentAddr(v) );
  }
  sqlite3VdbeAddOp(v, OP_IdxInsert, iIdx, 0);
  sqlite3VdbeAddOp(v, OP_Next, iTab, addr1+1);
  sqlite3VdbeChangeP2(v, addr1, sqlite3VdbeCurrentAddr(v));
  sqlite3VdbeAddOp(v, OP_Close, iTab, 0);
  sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
}

/*
** Create a new index for an SQL table.  pName1.pName2 is the name of the index 
** and pTblList is the name of the table that is to be indexed.  Both will 

**    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 1.110 2005/09/08 01:58:43 drh Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.

  int iCur,          /* Cursor number for the table */
  int count          /* Increment the row change counter */
){
  int addr;
  addr = sqlite3VdbeAddOp(v, OP_NotExists, iCur, 0);
  sqlite3GenerateRowIndexDelete(db, v, pTab, iCur, 0);
  sqlite3VdbeAddOp(v, OP_Delete, iCur, (count?OPFLAG_NCHANGE:0));
  sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
}

/*
** This routine generates VDBE code that causes the deletion of all
** index entries associated with a single row of a single table.
**
** The VDBE must be in a particular state when this routine is called.

**    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 1.228 2005/09/16 02:38:10 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
    testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
    assert( testAddr>0 || sqlite3_malloc_failed );
    sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, mem, 1);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;
      int addr;        /* Address of OP_OpenVirtual instruction */

          ** disable the test that was generated above that makes sure
          ** this code only executes once.  Because for a non-constant
          ** expression we need to rerun this code each time.
          */
          if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
            VdbeOp *aOp = sqlite3VdbeGetOp(v, testAddr-1);
            int i;
            for(i=0; i<4; i++){
              aOp[i].opcode = OP_Noop;
            }
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2);

      }
      sqlite3Select(pParse, pSel, sop, pExpr->iColumn, 0, 0, 0, 0);
      break;
    }
  }

  if( testAddr ){
    sqlite3VdbeChangeP2(v, testAddr, sqlite3VdbeCurrentAddr(v));
  }
  return;
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*
** Generate an instruction that will put the integer describe by

    case TK_AS: {
      sqlite3ExprCode(pParse, pExpr->pLeft);
      break;
    }
    case TK_CASE: {
      int expr_end_label;
      int jumpInst;
      int addr;
      int nExpr;
      int i;
      ExprList *pEList;
      struct ExprList_item *aListelem;

      assert(pExpr->pList);
      assert((pExpr->pList->nExpr % 2) == 0);

                                 OP_Ne, 0, 1);
          sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
        }else{
          jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
        }
        sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
        sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
        addr = sqlite3VdbeCurrentAddr(v);
        sqlite3VdbeChangeP2(v, jumpInst, addr);
      }
      if( pExpr->pLeft ){
        sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      }
      if( pExpr->pRight ){
        sqlite3ExprCode(pParse, pExpr->pRight);
      }else{

      addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);

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

      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
      break;
    }
    default: {
      sqlite3ExprCode(pParse, pExpr);
      sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
      break;

**    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 1.142 2005/07/21 18:23:20 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

      sqlite3VdbeAddOp(v, OP_Insert, srcTab, 0);
      sqlite3VdbeAddOp(v, OP_Return, 0, 0);

      /* The following code runs first because the GOTO at the very top
      ** of the program jumps to it.  Create the temporary table, then jump
      ** back up and execute the SELECT code above.
      */
      sqlite3VdbeChangeP2(v, iInitCode, sqlite3VdbeCurrentAddr(v));
      sqlite3VdbeAddOp(v, OP_OpenVirtual, srcTab, 0);
      sqlite3VdbeAddOp(v, OP_SetNumColumns, srcTab, nColumn);
      sqlite3VdbeAddOp(v, OP_Goto, 0, iSelectLoop);
      sqlite3VdbeResolveLabel(v, iCleanup);
    }else{
      sqlite3VdbeChangeP2(v, iInitCode, sqlite3VdbeCurrentAddr(v));
    }
  }else{
    /* This is the case if the data for the INSERT is coming from a VALUES
    ** clause
    */
    NameContext sNC;
    memset(&sNC, 0, sizeof(sNC));

    sqlite3VdbeAddOp(v, OP_SetNumColumns, newIdx, pTab->nCol);
  }
    
  /* Initialize the count of rows to be inserted
  */
  if( db->flags & SQLITE_CountRows ){
    iCntMem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iCntMem, 1);
  }

  /* Open tables and indices if there are no row triggers */
  if( !triggers_exist ){
    base = pParse->nTab;
    sqlite3OpenTableAndIndices(pParse, pTab, base, OP_OpenWrite);
  }

  int onError;
  int addr;
  int extra;
  int iCur;
  Index *pIdx;
  int seenReplace = 0;
  int jumpInst1=0, jumpInst2;
  int contAddr;
  int hasTwoRowids = (isUpdate && rowidChng);

  v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  nCol = pTab->nCol;

      }
      case OE_Replace: {
        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt);
        sqlite3VdbeAddOp(v, OP_Push, nCol-i, 0);
        break;
      }
    }
    sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));
  }

  /* Test all CHECK constraints
  */
  /**** TBD ****/

  /* If we have an INTEGER PRIMARY KEY, make sure the primary key

      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp(v, OP_Pop, nCol+1+hasTwoRowids, 0);
        sqlite3VdbeAddOp(v, OP_Goto, 0, ignoreDest);
        break;
      }
    }
    contAddr = sqlite3VdbeCurrentAddr(v);
    sqlite3VdbeChangeP2(v, jumpInst2, contAddr);
    if( isUpdate ){
      sqlite3VdbeChangeP2(v, jumpInst1, contAddr);
      sqlite3VdbeAddOp(v, OP_Dup, nCol+1, 1);
      sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
    }
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.

          sqlite3VdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRowids, 1);
          sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
        }
        seenReplace = 1;
        break;
      }
    }
    contAddr = sqlite3VdbeCurrentAddr(v);
#if NULL_DISTINCT_FOR_UNIQUE
    sqlite3VdbeChangeP2(v, jumpInst1, contAddr);
#endif
    sqlite3VdbeChangeP2(v, jumpInst2, contAddr);
  }
}

/*
** This routine generates code to finish the INSERT or UPDATE operation
** that was started by a prior call to sqlite3GenerateConstraintChecks.
** The stack must contain keys for all active indices followed by data

/*
** 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 1.99 2005/09/17 16:36:56 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/* Ignore this whole file if pragmas are disabled
*/

    }
  }else

#ifndef SQLITE_OMIT_INTEGRITY_CHECK
  if( sqlite3StrICmp(zLeft, "integrity_check")==0 ){
    int i, j, addr;

    /* Code that initializes the integrity check program.  Set the
    ** error count 0
    */
    static const VdbeOpList initCode[] = {
      { OP_Integer,     0, 0,        0},
      { OP_MemStore,    0, 1,        0},
    };

    /* Code that appears at the end of the integrity check.  If no error
    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static const VdbeOpList endCode[] = {
      { OP_MemLoad,     0, 0,        0},
      { OP_Integer,     0, 0,        0},
      { OP_Ne,          0, 0,        0},    /* 2 */
      { OP_String8,     0, 0,        "ok"},
      { OP_Callback,    1, 0,        0},
    };

    /* Initialize the VDBE program */
    if( sqlite3ReadSchema(pParse) ) goto pragma_out;
    sqlite3VdbeSetNumCols(v, 1);
    sqlite3VdbeSetColName(v, 0, "integrity_check", P3_STATIC);
    sqlite3VdbeAddOpList(v, ArraySize(initCode), initCode);

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

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

      for(x=sqliteHashFirst(&db->aDb[i].tblHash); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
        sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
        sqlite3VdbeAddOp(v, OP_MemStore, 1, 1);
        loopTop = sqlite3VdbeAddOp(v, OP_Rewind, 1, 0);
        sqlite3VdbeAddOp(v, OP_MemIncr, 1, 0);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2;
          static const VdbeOpList idxErr[] = {
            { OP_MemIncr,     0,  0,  0},
            { OP_String8,     0,  0,  "rowid "},
            { OP_Rowid,       1,  0,  0},
            { OP_String8,     0,  0,  " missing from index "},
            { OP_String8,     0,  0,  0},    /* 4 */
            { OP_Concat,      2,  0,  0},
            { OP_Callback,    1,  0,  0},
          };
          sqlite3GenerateIndexKey(v, pIdx, 1);
          jmp2 = sqlite3VdbeAddOp(v, OP_Found, j+2, 0);
          addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
          sqlite3VdbeChangeP3(v, addr+4, pIdx->zName, P3_STATIC);
          sqlite3VdbeChangeP2(v, jmp2, sqlite3VdbeCurrentAddr(v));
        }
        sqlite3VdbeAddOp(v, OP_Next, 1, loopTop+1);
        sqlite3VdbeChangeP2(v, loopTop, sqlite3VdbeCurrentAddr(v));
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          static const VdbeOpList cntIdx[] = {
             { OP_Integer,      0,  0,  0},
             { OP_MemStore,     2,  1,  0},
             { OP_Rewind,       0,  0,  0},  /* 2 */
             { OP_MemIncr,      2,  0,  0},
             { OP_Next,         0,  0,  0},  /* 4 */
             { OP_MemLoad,      1,  0,  0},
             { OP_MemLoad,      2,  0,  0},
             { OP_Eq,           0,  0,  0},  /* 7 */
             { OP_MemIncr,      0,  0,  0},
             { OP_String8,      0,  0,  "wrong # of entries in index "},
             { OP_String8,      0,  0,  0},  /* 10 */
             { OP_Concat,       0,  0,  0},
             { OP_Callback,     1,  0,  0},
          };
          if( pIdx->tnum==0 ) continue;
          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
          sqlite3VdbeChangeP1(v, addr+2, j+2);
          sqlite3VdbeChangeP2(v, addr+2, addr+5);
          sqlite3VdbeChangeP1(v, addr+4, j+2);
          sqlite3VdbeChangeP2(v, addr+4, addr+3);
          sqlite3VdbeChangeP2(v, addr+7, addr+ArraySize(cntIdx));
          sqlite3VdbeChangeP3(v, addr+10, pIdx->zName, P3_STATIC);
        }
      } 
    }
    addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
    sqlite3VdbeChangeP2(v, addr+2, addr+ArraySize(endCode));
  }else
#endif /* SQLITE_OMIT_INTEGRITY_CHECK */

#ifndef SQLITE_OMIT_UTF16
  /*
  **   PRAGMA encoding
  **   PRAGMA encoding = "utf-8"|"utf-16"|"utf-16le"|"utf-16be"

**    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 1.274 2005/09/20 13:55:18 drh Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.

        pushOntoSorter(pParse, v, pOrderBy);
      }else{
        char aff = (iParm>>16)&0xFF;
        aff = sqlite3CompareAffinity(pEList->a[0].pExpr, aff);
        sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &aff, 1);
        sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
      }
      sqlite3VdbeChangeP2(v, addr2, sqlite3VdbeCurrentAddr(v));
      break;
    }

    /* If this is a scalar select that is part of an expression, then
    ** store the results in the appropriate memory cell and break out
    ** of the scan loop.
    */

** The aggregate accumulator is a set of memory cells that hold
** intermediate results while calculating an aggregate.  This
** routine simply stores NULLs in all of those memory cells.
*/
static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  int addr;
  struct AggInfo_func *pFunc;
  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
    return;
  }
  sqlite3VdbeAddOp(v, OP_Null, 0, 0);
  for(i=0; i<pAggInfo->nColumn; i++){
    addr = sqlite3VdbeAddOp(v, OP_MemStore, pAggInfo->aCol[i].iMem, 0);
  }
  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
    addr = sqlite3VdbeAddOp(v, OP_MemStore, pFunc->iMem, 0);
    if( pFunc->iDistinct>=0 ){
      Expr *pE = pFunc->pExpr;
      if( pE->pList==0 || pE->pList->nExpr!=1 ){
        sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
           "by an expression");
        pFunc->iDistinct = -1;
      }else{
        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
        sqlite3VdbeOp3(v, OP_OpenVirtual, pFunc->iDistinct, 0, 
                          (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
      }
    }
  }
  sqlite3VdbeChangeP2(v, addr, 1);
}

/*
** Invoke the OP_AggFinalize opcode for every aggregate function
** in the AggInfo structure.
*/
static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){

  if( eDest==SRT_VirtualTab ){
    sqlite3VdbeAddOp(v, OP_OpenVirtual, iParm, pEList->nExpr);
  }


  /* Initialize the memory cell to NULL for SRT_Mem or 0 for SRT_Exists
  */
  if( eDest==SRT_Mem || eDest==SRT_Exists ){
    sqlite3VdbeAddOp(v, eDest==SRT_Mem ? OP_Null : OP_Integer, 0, 0);

    sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
  }

  /* Open a virtual index to use for the distinct set.
  */
  if( isDistinct ){
    KeyInfo *pKeyInfo;
    distinct = pParse->nTab++;

      */
      iUseFlag = pParse->nMem++;
      iAbortFlag = pParse->nMem++;
      iAMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      iBMem = pParse->nMem;
      pParse->nMem += pGroupBy->nExpr;
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
      sqlite3VdbeAddOp(v, OP_MemStore, iAbortFlag, 0);
      sqlite3VdbeAddOp(v, OP_MemStore, iUseFlag, 1);
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp(v, OP_MemStore, iAMem, 1);
      sqlite3VdbeAddOp(v, OP_Goto, 0, addrInitializeLoop);

      /* Generate a subroutine that outputs a single row of the result
      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
      ** is less than or equal to zero, the subroutine is a no-op.  If
      ** the processing calls for the query to abort, this subroutine
      ** increments the iAbortFlag memory location before returning in

      ** This code copies current group by terms in b0,b1,b2,...
      ** over to a0,a1,a2.  It then calls the output subroutine
      ** and resets the aggregate accumulator registers in preparation
      ** for the next GROUP BY batch.
      */
      sqlite3VdbeResolveLabel(v, addrGroupByChange);
      for(j=0; j<pGroupBy->nExpr; j++){
        sqlite3VdbeAddOp(v, OP_MemLoad, iBMem+j, 0);
        sqlite3VdbeAddOp(v, OP_MemStore, iAMem+j, 1);
      }
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
      sqlite3VdbeAddOp(v, OP_IfMemPos, iAbortFlag, addrEnd);
      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);

      /* 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 1.111 2005/09/08 01:58:43 drh Exp $
*/
#include "sqliteInt.h"

/*
** The most recently coded instruction was an OP_Column to retrieve column
** 'i' of table pTab. This routine sets the P3 parameter of the 
** OP_Column to the default value, if any.

    }
  }

  /* Repeat the above with the next record to be updated, until
  ** all record selected by the WHERE clause have been updated.
  */
  sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
  sqlite3VdbeChangeP2(v, addr, sqlite3VdbeCurrentAddr(v));

  /* Close all tables if there were no FOR EACH ROW triggers */
  if( !triggers_exist ){
    for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      if( openAll || aIdxUsed[i] ){
        sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
      }

**
** 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 1.490 2005/09/20 13:55:18 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  if( pMem->i>0 ){
     pc = pOp->p2 - 1;
  }
  break;
}


































/* Opcode: AggStep P1 P2 P3
**
** Execute the step function for an aggregate.  The
** function has P2 arguments.  P3 is a pointer to the FuncDef
** structure that specifies the function.  Use memory location
** P1 as the accumulator.

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.98 2005/09/07 21:22:47 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines

Vdbe *sqlite3VdbeCreate(sqlite3*);
void sqlite3VdbeCreateCallback(Vdbe*, int*);
int sqlite3VdbeAddOp(Vdbe*,int,int,int);
int sqlite3VdbeOp3(Vdbe*,int,int,int,const char *zP3,int);
int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);

void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N);
VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
int sqlite3VdbeMakeLabel(Vdbe*);
void sqlite3VdbeDelete(Vdbe*);
void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int);
int sqlite3VdbeFinalize(Vdbe*);
void sqlite3VdbeResolveLabel(Vdbe*, int);

  assert( val>=0 );
  assert( p->magic==VDBE_MAGIC_INIT );
  if( p && addr>=0 && p->nOp>addr && p->aOp ){
    p->aOp[addr].p2 = val;
  }
}









/*
** Delete a P3 value if necessary.
*/
static void freeP3(int p3type, void *p3){
  if( p3 ){
    switch( p3type ){

/*
** Delete any previous value and set the value stored in *pMem to NULL.
*/
void sqlite3VdbeMemSetNull(Mem *pMem){
  sqlite3VdbeMemRelease(pMem);
  pMem->flags = MEM_Null;
  pMem->type = SQLITE_NULL;

}

/*
** Delete any previous value and set the value stored in *pMem to val,
** manifest type INTEGER.
*/
void sqlite3VdbeMemSetInt64(Mem *pMem, i64 val){

** 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 1.178 2005/09/20 08:47:20 drh Exp $
*/
#include "sqliteInt.h"

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

    /* If this is the right table of a LEFT OUTER JOIN, allocate and
    ** initialize a memory cell that records if this table matches any
    ** row of the left table of the join.
    */
    if( pLevel->iFrom>0 && (pTabItem[-1].jointype & JT_LEFT)!=0 ){
      if( !pParse->nMem ) pParse->nMem++;
      pLevel->iLeftJoin = pParse->nMem++;
      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
      sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);
      VdbeComment((v, "# init LEFT JOIN no-match flag"));
    }

    if( pLevel->flags & WHERE_ROWID_EQ ){
      /* Case 1:  We can directly reference a single row using an
      **          equality comparison against the ROWID field.  Or
      **          we reference multiple rows using a "rowid IN (...)"

    }

    /* For a LEFT OUTER JOIN, generate code that will record the fact that
    ** at least one row of the right table has matched the left table.  
    */
    if( pLevel->iLeftJoin ){
      pLevel->top = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
      sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iLeftJoin, 1);
      VdbeComment((v, "# record LEFT JOIN hit"));
      for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){
        if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue;
        if( (pTerm->prereqAll & notReady)!=0 ) continue;
        assert( pTerm->pExpr );
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, 1);
        pTerm->flags |= TERM_CODED;

      for(j=pLevel->nIn, a=&pLevel->aInLoop[j*3-3]; j>0; j--, a-=3){
        sqlite3VdbeAddOp(v, a[0], a[1], a[2]);
      }
      sqliteFree(pLevel->aInLoop);
    }
    if( pLevel->iLeftJoin ){
      int addr;
      addr = sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iLeftJoin, 0);
      sqlite3VdbeAddOp(v, OP_NotNull, 1, addr+4 + (pLevel->iIdxCur>=0));
      sqlite3VdbeAddOp(v, OP_NullRow, pTabList->a[i].iCursor, 0);
      if( pLevel->iIdxCur>=0 ){
        sqlite3VdbeAddOp(v, OP_NullRow, pLevel->iIdxCur, 0);
      }
      sqlite3VdbeAddOp(v, OP_Goto, 0, pLevel->top);

    }
  }

  /* The "break" point is here, just past the end of the outer loop.
  ** Set it.
  */
  sqlite3VdbeResolveLabel(v, pWInfo->iBreak);