SQLite

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.248 2004/08/18 15:58:23 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

  /* Get the VDBE program ready for execution
  */
  if( v && pParse->nErr==0 ){
    FILE *trace = (db->flags & SQLITE_VdbeTrace)!=0 ? stdout : 0;
    sqlite3VdbeTrace(v, trace);
    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->explain);

    pParse->rc = pParse->nErr ? SQLITE_ERROR : SQLITE_DONE;
    pParse->colNamesSet = 0;
  }else if( pParse->rc==SQLITE_OK ){
    pParse->rc = SQLITE_ERROR;
  }
  pParse->nTab = 0;
  pParse->nMem = 0;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
** $Id: delete.c,v 1.77 2004/06/21 18:14:47 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.

    oldIdx = pParse->nTab++;
  }

  /* Resolve the column names in all the expressions.
  */
  assert( pTabList->nSrc==1 );
  iCur = pTabList->a[0].iCursor = pParse->nTab++;
  if( pWhere ){
    if( sqlite3ExprResolveIds(pParse, pTabList, 0, pWhere) ){
      goto delete_from_cleanup;
    }
    if( sqlite3ExprCheck(pParse, pWhere, 0, 0) ){
      goto delete_from_cleanup;
    }
  }

  /* Start the view context
  */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

    if( !isView ){
      /* Open cursors for the table we are deleting from and all its
      ** indices.  If there are row triggers, this happens inside the
      ** OP_ListRead loop because the cursor have to all be closed
      ** before the trigger fires.  If there are no row triggers, the
      ** cursors are opened only once on the outside the loop.
      */
      pParse->nTab = iCur + 1;
      sqlite3OpenTableAndIndices(pParse, pTab, iCur);

      /* This is the beginning of the delete loop when there are no
      ** row triggers */
      if( !row_triggers_exist ){ 
        addr = sqlite3VdbeAddOp(v, OP_ListRead, 0, end);
      }

    /* Close the cursors after the loop if there are no row triggers */
    if( !row_triggers_exist ){
      for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
        sqlite3VdbeAddOp(v, OP_Close, iCur + i, pIdx->tnum);
      }
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
      pParse->nTab = iCur;
    }
  }
  sqlite3EndWriteOperation(pParse);

  /*
  ** Return the number of rows that were deleted.
  */

**    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 1.156 2004/08/20 16:02:39 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

char const *sqlite3AffinityString(char affinity){
  switch( affinity ){
    case SQLITE_AFF_INTEGER: return "i";

        }
      }
      break;
    }
  }
  return nErr;
}






















/*
** Generate an instruction that will put the integer describe by
** text z[0..n-1] on the stack.
*/
static void codeInteger(Vdbe *v, const char *z, int n){
  int i;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.114 2004/07/24 17:38:29 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:

    assert( pList!=0 );
    srcTab = -1;
    useTempTable = 0;
    assert( pList );
    nColumn = pList->nExpr;
    dummy.nSrc = 0;
    for(i=0; i<nColumn; i++){
      if( sqlite3ExprResolveIds(pParse, &dummy, 0, pList->a[i].pExpr) ){
        goto insert_cleanup;
      }
      if( sqlite3ExprCheck(pParse, pList->a[i].pExpr, 0, 0) ){
        goto insert_cleanup;
      }
    }
  }

  /* Make sure the number of columns in the source data matches the number
  ** of columns to be inserted into the table.

    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, iCntMem, 1);
  }

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

  /* If the data source is a temporary table, then we have to create
  ** a loop because there might be multiple rows of data.  If the data
  ** source is a subroutine call from the SELECT statement, then we need
  ** to launch the SELECT statement processing.
  */

  }

  /* If any triggers exists, the opening of tables and indices is deferred
  ** until now.
  */
  if( row_triggers_exist && !isView ){
    base = pParse->nTab;
    idx = sqlite3OpenTableAndIndices(pParse, pTab, base);
    pParse->nTab += idx;
  }

  /* Push the record number for the new entry onto the stack.  The
  ** record number is a randomly generate integer created by NewRecno
  ** except when the table has an INTEGER PRIMARY KEY column, in which
  ** case the record number is the same as that column. 
  */

  
  if( isUpdate && recnoChng ){
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
  }
}

/*
** Generate code that will open write cursors for a table and for all
** indices of that table.  The "base" parameter is the cursor number used
** for the table.  Indices are opened on subsequent cursors.
**
** Return the total number of cursors opened.  This is always at least
** 1 (for the main table) plus more for each cursor.
*/
int sqlite3OpenTableAndIndices(Parse *pParse, Table *pTab, int base){





  int i;
  Index *pIdx;
  Vdbe *v = sqlite3GetVdbe(pParse);
  assert( v!=0 );
  sqlite3VdbeAddOp(v, OP_Integer, pTab->iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, base, pTab->tnum);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, base, pTab->nCol);
  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    sqlite3VdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
    sqlite3VdbeOp3(v, OP_OpenWrite, i+base, pIdx->tnum,
                   (char*)&pIdx->keyInfo, P3_KEYINFO);
  }
  return i;

}

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.252 2004/08/18 02:10:15 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** The following constant value is used by the SQLITE_BIGENDIAN and

** the prior execution is returned.
**
** This routine sets the error code and string returned by
** sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16().
*/
int sqlite3_reset(sqlite3_stmt *pStmt){
  int rc = sqlite3VdbeReset((Vdbe*)pStmt);
  sqlite3VdbeMakeReady((Vdbe*)pStmt, -1, 0);
  return rc;
}

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation(

/*
** 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 1.59 2004/08/08 20:22:18 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
# include "pager.h"
# include "btree.h"

    ** messages have been generated, output OK.  Otherwise output the
    ** error message
    */
    static 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);

      sqlite3CodeVerifySchema(pParse, i);
      for(x=sqliteHashFirst(&db->aDb[i].tblHash); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        int loopTop;

        if( pTab->pIndex==0 ) continue;
        sqlite3VdbeAddOp(v, OP_Integer, i, 0);
        sqlite3VdbeAddOp(v, OP_OpenRead, 1, pTab->tnum);
        sqlite3VdbeAddOp(v, OP_SetNumColumns, 1, pTab->nCol);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          if( pIdx->tnum==0 ) continue;
          sqlite3VdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
          sqlite3VdbeOp3(v, OP_OpenRead, j+2, pIdx->tnum, 
                         (char*)&pIdx->keyInfo, P3_KEYINFO);
        }
        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 VdbeOpList idxErr[] = {
            { OP_MemIncr,     0,  0,  0},
            { OP_String8,      0,  0,  "rowid "},
            { OP_Recno,       1,  0,  0},
            { OP_String8,      0,  0,  " missing from index "},
            { OP_String8,      0,  0,  0},    /* 4 */
            { OP_Concat8,      4,  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));

             { 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_Concat8,       2,  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);

**    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 1.202 2004/07/26 23:32:27 drh Exp $
*/
#include "sqliteInt.h"


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

*/
int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
  int jointype = 0;
  Token *apAll[3];
  Token *p;
  static struct {
    const char *zKeyword;
    int nChar;
    int code;
  } keywords[] = {
    { "natural", 7, JT_NATURAL },
    { "left",    4, JT_LEFT|JT_OUTER },
    { "right",   5, JT_RIGHT|JT_OUTER },
    { "full",    4, JT_LEFT|JT_RIGHT|JT_OUTER },
    { "outer",   5, JT_OUTER },
    { "inner",   5, JT_INNER },

** Given a SELECT statement, generate a Table structure that describes
** the result set of that SELECT.
*/
Table *sqlite3ResultSetOfSelect(Parse *pParse, char *zTabName, Select *pSelect){
  Table *pTab;
  int i, j;
  ExprList *pEList;
  Column *aCol;

  if( fillInColumnList(pParse, pSelect) ){
    return 0;
  }
  pTab = sqliteMalloc( sizeof(Table) );
  if( pTab==0 ){
    return 0;
  }
  pTab->zName = zTabName ? sqliteStrDup(zTabName) : 0;
  pEList = pSelect->pEList;
  pTab->nCol = pEList->nExpr;
  assert( pTab->nCol>0 );
  pTab->aCol = aCol = sqliteMalloc( sizeof(pTab->aCol[0])*pTab->nCol );
  for(i=0; i<pTab->nCol; i++){
    Expr *pR;
    char *zType;
    Expr *p = pEList->a[i].pExpr;

    if( pEList->a[i].zName ){
      aCol[i].zName = sqliteStrDup(pEList->a[i].zName);
    }else if( p->op==TK_DOT 
               && (pR=p->pRight)!=0 && pR->token.z && pR->token.z[0] ){
      int cnt;
      sqlite3SetNString(&aCol[i].zName, pR->token.z, pR->token.n, 0);
      for(j=cnt=0; j<i; j++){
        if( sqlite3StrICmp(aCol[j].zName, aCol[i].zName)==0 ){
          int n;
          char zBuf[30];
          sprintf(zBuf,"_%d",++cnt);
          n = strlen(zBuf);
          sqlite3SetNString(&aCol[i].zName, pR->token.z, pR->token.n, zBuf,n,0);
          j = -1;
        }
      }
    }else if( p->span.z && p->span.z[0] ){
      sqlite3SetNString(&pTab->aCol[i].zName, p->span.z, p->span.n, 0);
    }else{
      char zBuf[30];
      sprintf(zBuf, "column%d", i+1);
      pTab->aCol[i].zName = sqliteStrDup(zBuf);
    }
    sqlite3Dequote(aCol[i].zName);

    zType = sqliteStrDup(columnType(pParse, pSelect->pSrc ,p));
    pTab->aCol[i].zType = zType;
    pTab->aCol[i].affinity = SQLITE_AFF_NUMERIC;
    if( zType ){
      pTab->aCol[i].affinity = sqlite3AffinityType(zType, strlen(zType));
    }
    pTab->aCol[i].pColl = sqlite3ExprCollSeq(pParse, p);
    if( !pTab->aCol[i].pColl ){
      pTab->aCol[i].pColl = pParse->db->pDfltColl;
    }
  }
  pTab->iPKey = -1;
  return pTab;
}

/*

** in pParse and return non-zero.
*/
static int fillInColumnList(Parse *pParse, Select *p){
  int i, j, k, rc;
  SrcList *pTabList;
  ExprList *pEList;
  Table *pTab;


  if( p==0 || p->pSrc==0 ) return 1;
  pTabList = p->pSrc;
  pEList = p->pEList;

  /* Look up every table in the table list.
  */
  for(i=0; i<pTabList->nSrc; i++){
    if( pTabList->a[i].pTab ){
      /* This routine has run before!  No need to continue */
      return 0;
    }
    if( pTabList->a[i].zName==0 ){
      /* A sub-query in the FROM clause of a SELECT */
      assert( pTabList->a[i].pSelect!=0 );
      if( pTabList->a[i].zAlias==0 ){
        char zFakeName[60];
        sprintf(zFakeName, "sqlite_subquery_%p_",
           (void*)pTabList->a[i].pSelect);
        sqlite3SetString(&pTabList->a[i].zAlias, zFakeName, 0);
      }
      pTabList->a[i].pTab = pTab = 
        sqlite3ResultSetOfSelect(pParse, pTabList->a[i].zAlias,
                                        pTabList->a[i].pSelect);
      if( pTab==0 ){
        return 1;
      }
      /* The isTransient flag indicates that the Table structure has been
      ** dynamically allocated and may be freed at any time.  In other words,
      ** pTab is not pointing to a persistent table structure that defines
      ** part of the schema. */
      pTab->isTransient = 1;
    }else{
      /* An ordinary table or view name in the FROM clause */
      pTabList->a[i].pTab = pTab = 
        sqlite3LocateTable(pParse,pTabList->a[i].zName,pTabList->a[i].zDatabase);
      if( pTab==0 ){
        return 1;
      }
      if( pTab->pSelect ){
        /* We reach here if the named table is a really a view */
        if( sqlite3ViewGetColumnNames(pParse, pTab) ){
          return 1;
        }
        /* If pTabList->a[i].pSelect!=0 it means we are dealing with a
        ** view within a view.  The SELECT structure has already been
        ** copied by the outer view so we can skip the copy step here
        ** in the inner view.
        */
        if( pTabList->a[i].pSelect==0 ){
          pTabList->a[i].pSelect = sqlite3SelectDup(pTab->pSelect);
        }
      }
    }
  }

  /* Process NATURAL keywords, and ON and USING clauses of joins.
  */

        int tableSeen = 0;      /* Set to 1 when TABLE matches */
        char *zTName;            /* text of name of TABLE */
        if( pE->op==TK_DOT && pE->pLeft ){
          zTName = sqlite3NameFromToken(&pE->pLeft->token);
        }else{
          zTName = 0;
        }
        for(i=0; i<pTabList->nSrc; i++){
          Table *pTab = pTabList->a[i].pTab;
          char *zTabName = pTabList->a[i].zAlias;
          if( zTabName==0 || zTabName[0]==0 ){ 
            zTabName = pTab->zName;
          }
          if( zTName && (zTabName==0 || zTabName[0]==0 || 
                 sqlite3StrICmp(zTName, zTabName)!=0) ){
            continue;
          }

  Vdbe *v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db);
  }
  return v;
}

#if 0  /***** This routine needs deleting *****/
static void multiSelectAffinity(Select *p, char *zAff){
  int i;

  if( !p ) return;
  multiSelectAffinity(p->pPrior, zAff);

  for(i=0; i<p->pEList->nExpr; i++){
    if( zAff[i]=='\0' ){
      zAff[i] = sqlite3ExprAffinity(p->pEList->a[i].pExpr);
    }
  }
}
#endif

/*
** Compute the iLimit and iOffset fields of the SELECT based on the
** nLimit and nOffset fields.  nLimit and nOffset hold the integers
** that appear in the original SQL statement after the LIMIT and OFFSET
** keywords.  Or that hold -1 and 0 if those keywords are omitted.
** iLimit and iOffset are the integer memory register numbers for
** counters used to compute the limit and offset.  If there is no

  eList.a[0].pExpr = pExpr;
  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, eDest, iParm, cont, cont, 0);
  sqlite3VdbeResolveLabel(v, cont);
  sqlite3VdbeAddOp(v, OP_Close, base, 0);
  
  return 1;
}













































/*
** Generate code for the given SELECT statement.
**
** The results are distributed in various ways depending on the
** value of eDest and iParm.
**

  /* At this point, we should have allocated all the cursors that we
  ** need to handle subquerys and temporary tables.  
  **
  ** Resolve the column names and do a semantics check on all the expressions.
  */
  for(i=0; i<pEList->nExpr; i++){
    if( sqlite3ExprResolveIds(pParse, pTabList, 0, pEList->a[i].pExpr) ){
      goto select_end;
    }
    if( sqlite3ExprCheck(pParse, pEList->a[i].pExpr, 1, &isAgg) ){
      goto select_end;
    }
  }
  if( pWhere ){
    if( sqlite3ExprResolveIds(pParse, pTabList, pEList, pWhere) ){
      goto select_end;
    }
    if( sqlite3ExprCheck(pParse, pWhere, 0, 0) ){
      goto select_end;
    }
  }
  if( pHaving ){
    if( pGroupBy==0 ){
      sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
      goto select_end;
    }
    if( sqlite3ExprResolveIds(pParse, pTabList, pEList, pHaving) ){
      goto select_end;
    }
    if( sqlite3ExprCheck(pParse, pHaving, 1, &isAgg) ){
      goto select_end;
    }
  }
  if( pOrderBy ){
    for(i=0; i<pOrderBy->nExpr; i++){
      int iCol;
      Expr *pE = pOrderBy->a[i].pExpr;
      if( sqlite3ExprIsInteger(pE, &iCol) && iCol>0 && iCol<=pEList->nExpr ){
        sqlite3ExprDelete(pE);
        pE = pOrderBy->a[i].pExpr = sqlite3ExprDup(pEList->a[iCol-1].pExpr);
      }
      if( sqlite3ExprResolveIds(pParse, pTabList, pEList, pE) ){
        goto select_end;
      }
      if( sqlite3ExprCheck(pParse, pE, isAgg, 0) ){
        goto select_end;
      }
      if( sqlite3ExprIsConstant(pE) ){
        if( sqlite3ExprIsInteger(pE, &iCol)==0 ){
          sqlite3ErrorMsg(pParse,
             "ORDER BY terms must not be non-integer constants");
          goto select_end;
        }else if( iCol<=0 || iCol>pEList->nExpr ){
          sqlite3ErrorMsg(pParse, 
             "ORDER BY column number %d out of range - should be "
             "between 1 and %d", iCol, pEList->nExpr);
          goto select_end;
        }
      }
    }
  }
  if( pGroupBy ){
    for(i=0; i<pGroupBy->nExpr; i++){
      int iCol;
      Expr *pE = pGroupBy->a[i].pExpr;
      if( sqlite3ExprIsInteger(pE, &iCol) && iCol>0 && iCol<=pEList->nExpr ){
        sqlite3ExprDelete(pE);
        pE = pGroupBy->a[i].pExpr = sqlite3ExprDup(pEList->a[iCol-1].pExpr);
      }
      if( sqlite3ExprResolveIds(pParse, pTabList, pEList, pE) ){
        goto select_end;
      }
      if( sqlite3ExprCheck(pParse, pE, isAgg, 0) ){
        goto select_end;
      }
      if( sqlite3ExprIsConstant(pE) ){
        if( sqlite3ExprIsInteger(pE, &iCol)==0 ){
          sqlite3ErrorMsg(pParse,
            "GROUP BY terms must not be non-integer constants");
          goto select_end;
        }else if( iCol<=0 || iCol>pEList->nExpr ){
          sqlite3ErrorMsg(pParse,
             "GROUP BY column number %d out of range - should be "
             "between 1 and %d", iCol, pEList->nExpr);
          goto select_end;
        }
      }
    }
  }

  /* Begin generating code.
  */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto select_end;

/*
** 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 1.315 2004/08/08 20:22:18 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

#include "config.h"
#include "sqlite3.h"
#include "hash.h"

*/
struct WhereInfo {
  Parse *pParse;
  SrcList *pTabList;   /* List of tables in the join */
  int iContinue;       /* Jump here to continue with next record */
  int iBreak;          /* Jump here to break out of the loop */
  int nLevel;          /* Number of nested loop */
  int savedNTab;       /* Value of pParse->nTab before WhereBegin() */
  int peakNTab;        /* Value of pParse->nTab after WhereBegin() */
  WhereLevel a[1];     /* Information about each nest loop in the WHERE */
};

/*
** An instance of the following structure contains all information
** needed to generate code for a single SELECT statement.
**

int sqlite3RunVacuum(char**, sqlite*);
int sqlite3GlobCompare(const unsigned char*,const unsigned char*);
char *sqlite3NameFromToken(Token*);
int sqlite3ExprCheck(Parse*, Expr*, int, int*);
int sqlite3ExprCompare(Expr*, Expr*);
int sqliteFuncId(Token*);
int sqlite3ExprResolveIds(Parse*, SrcList*, ExprList*, Expr*);

int sqlite3ExprAnalyzeAggregates(Parse*, Expr*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3Randomness(int, void*);
void sqlite3RollbackAll(sqlite*);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3BeginTransaction(Parse*);
void sqlite3CommitTransaction(Parse*);
void sqlite3RollbackTransaction(Parse*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsInteger(Expr*, int*);
int sqlite3IsRowid(const char*);
void sqlite3GenerateRowDelete(sqlite*, Vdbe*, Table*, int, int);
void sqlite3GenerateRowIndexDelete(sqlite*, Vdbe*, Table*, int, char*);
void sqlite3GenerateIndexKey(Vdbe*, Index*, int);
void sqlite3GenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
void sqlite3CompleteInsertion(Parse*, Table*, int, char*, int, int, int);
int sqlite3OpenTableAndIndices(Parse*, Table*, int);
void sqlite3BeginWriteOperation(Parse*, int, int);
void sqlite3EndWriteOperation(Parse*);
Expr *sqlite3ExprDup(Expr*);
void sqlite3TokenCopy(Token*, Token*);
ExprList *sqlite3ExprListDup(ExprList*);
SrcList *sqlite3SrcListDup(SrcList*);
IdList *sqlite3IdListDup(IdList*);

  TriggerStep *pStepList,   /* List of statements inside the trigger body */
  int orconfin              /* Conflict algorithm. (OE_Abort, etc) */  
){
  TriggerStep * pTriggerStep = pStepList;
  int orconf;

  while( pTriggerStep ){
    int saveNTab = pParse->nTab;
 
    orconf = (orconfin == OE_Default)?pTriggerStep->orconf:orconfin;
    pParse->trigStack->orconf = orconf;
    switch( pTriggerStep->op ){
      case TK_SELECT: {
	Select * ss = sqlite3SelectDup(pTriggerStep->pSelect);		  
	assert(ss);
	assert(ss->pSrc);

        sqlite3VdbeAddOp(pParse->pVdbe, OP_ListPop, 0, 0);
        sqlite3VdbeAddOp(pParse->pVdbe, OP_ResetCount, 1, 0);
        break;
      }
      default:
        assert(0);
    } 
    pParse->nTab = saveNTab;
    pTriggerStep = pTriggerStep->pNext;
  }

  return 0;
}

/*

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.85 2004/06/21 06:50:29 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
**
**   UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL;

  ** of the UPDATE statement.  Also find the column index
  ** for each column to be updated in the pChanges array.  For each
  ** column to be updated, make sure we have authorization to change
  ** that column.
  */
  chngRecno = 0;
  for(i=0; i<pChanges->nExpr; i++){
    if( sqlite3ExprResolveIds(pParse, pTabList, 0, pChanges->a[i].pExpr) ){
      goto update_cleanup;
    }
    if( sqlite3ExprCheck(pParse, pChanges->a[i].pExpr, 0, 0) ){
      goto update_cleanup;
    }
    for(j=0; j<pTab->nCol; j++){
      if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){
        if( j==pTab->iPKey ){
          chngRecno = 1;
          pRecnoExpr = pChanges->a[i].pExpr;

      aIdxUsed[j] = 0;
    }
  }

  /* Resolve the column names in all the expressions in the
  ** WHERE clause.
  */
  if( pWhere ){
    if( sqlite3ExprResolveIds(pParse, pTabList, 0, pWhere) ){
      goto update_cleanup;
    }
    if( sqlite3ExprCheck(pParse, pWhere, 0, 0) ){
      goto update_cleanup;
    }
  }

  /* Start the view context
  */
  if( isView ){
    sqlite3AuthContextPush(pParse, &sContext, pTab->zName);
  }

  if( row_triggers_exist ){
    if( !isView ){
      for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
        if( openAll || aIdxUsed[i] )
          sqlite3VdbeAddOp(v, OP_Close, iCur+i+1, 0);
      }
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
      pParse->nTab = iCur;
    }
    if( sqlite3CodeRowTrigger(pParse, TK_UPDATE, pChanges, TK_AFTER, pTab, 
          newIdx, oldIdx, onError, addr) ){
      goto update_cleanup;
    }
  }

  if( !row_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);
      }
    }
    sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    pParse->nTab = iCur;
  }else{
    sqlite3VdbeAddOp(v, OP_Close, newIdx, 0);
    sqlite3VdbeAddOp(v, OP_Close, oldIdx, 0);
  }

  sqlite3EndWriteOperation(pParse);

**
** 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 1.408 2004/08/08 23:39:19 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

/*
** Allocate cursor number iCur.  Return a pointer to it.  Return NULL
** if we run out of memory.
*/
static Cursor *allocateCursor(Vdbe *p, int iCur){
  Cursor *pCx;
  if( iCur>=p->nCursor ){
    int i;
    p->apCsr = sqliteRealloc( p->apCsr, (iCur+1)*sizeof(Cursor*) );
    if( p->apCsr==0 ){
      p->nCursor = 0;
      return 0;
    }
    for(i=p->nCursor; i<iCur; i++){
      p->apCsr[i] = 0;
    }
    p->nCursor = iCur+1;
  }else if( p->apCsr[iCur] ){
    sqlite3VdbeFreeCursor(p->apCsr[iCur]);
  }
  p->apCsr[iCur] = pCx = sqliteMalloc( sizeof(Cursor) );
  return pCx;
}

/*

** sqlite3_bind() API.
*/
case OP_Variable: {
  int j = pOp->p1 - 1;
  assert( j>=0 && j<p->nVar );

  pTos++;
  /* sqlite3VdbeMemCopyStatic(pTos, &p->apVar[j]); */
  memcpy(pTos, &p->apVar[j], sizeof(*pTos)-NBFS);
  pTos->xDel = 0;
  if( pTos->flags&(MEM_Str|MEM_Blob) ){
    pTos->flags &= ~(MEM_Dyn|MEM_Ephem|MEM_Short);
    pTos->flags |= MEM_Static;
  }
  break;
}

    apSorter[i] = 0;
  }
  while( p->pSort ){
    pElem = p->pSort;
    p->pSort = pElem->pNext;
    pElem->pNext = 0;
    for(i=0; i<NSORT-1; i++){
    if( apSorter[i]==0 ){
        apSorter[i] = pElem;
        break;
      }else{
        pElem = Merge(apSorter[i], pElem, pKeyInfo);
        apSorter[i] = 0;
      }
    }

** stack is popped once if P2 is 1.  If P2 is zero, then
** the original data remains on the stack.
*/
case OP_MemStore: {
  int i = pOp->p1;
  Mem *pMem;
  assert( pTos>=p->aStack );
  if( i>=p->nMem ){
    int nOld = p->nMem;
    Mem *aMem;
    p->nMem = i + 5;
    aMem = sqliteRealloc(p->aMem, p->nMem*sizeof(p->aMem[0]));
    if( aMem==0 ) goto no_mem;
    if( aMem!=p->aMem ){
      int j;
      for(j=0; j<nOld; j++){
        if( aMem[j].flags & MEM_Short ){
          aMem[j].z = aMem[j].zShort;
        }
      }
    }
    p->aMem = aMem;
    if( nOld<p->nMem ){
      memset(&p->aMem[nOld], 0, sizeof(p->aMem[0])*(p->nMem-nOld));
    }
  }
  Deephemeralize(pTos);
  pMem = &p->aMem[i];
  Release(pMem);
  *pMem = *pTos;
  if( pMem->flags & MEM_Dyn ){
    if( pOp->p2 ){
      pTos->flags = MEM_Null;
    }else{
      pMem->z = sqliteMallocRaw( pMem->n+2 );
      if( pMem->z==0 ) goto no_mem;
      memcpy(pMem->z, pTos->z, pMem->n);
      memcpy(&pMem->z[pMem->n], "\000", 2);
      pMem->flags |= MEM_Term;
    }
  }else if( pMem->flags & MEM_Short ){
    pMem->z = pMem->zShort;
  }
  if( pOp->p2 ){
    Release(pTos);
    pTos--;
  }




  break;
}

/* Opcode: MemLoad P1 * *
**
** Push a copy of the value in memory location P1 onto the stack.
**
** If the value is a string, then the value pushed is a pointer to
** the string that is stored in the memory location.  If the memory
** location is subsequently changed (using OP_MemStore) then the

  rc = sqlite3BtreeMoveto(p->agg.pCsr, zKey, nKey, &res);
  if( rc!=SQLITE_OK ){
    goto abort_due_to_error;
  }
  if( res==0 ){
    rc = sqlite3BtreeData(p->agg.pCsr, 0, sizeof(AggElem*),
        (char *)&p->agg.pCurrent);
    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
    pc = pOp->p2 - 1;
  }else{
    rc = AggInsert(&p->agg, zKey, nKey);

    if( rc!=SQLITE_OK ){
      goto abort_due_to_error;
    }
  }
  Release(pTos);
  pTos--;
  break; 
}

/* Opcode: AggSet * P2 *

  assert( pTos>=p->aStack );
  if( pFocus==0 ) goto no_mem;
  assert( i>=0 && i<p->agg.nMem );
  Deephemeralize(pTos);
  pMem = &pFocus->aMem[i];
  Release(pMem);
  *pMem = *pTos;
  if( pMem->flags & MEM_Dyn ){
    pTos->flags = MEM_Null;
  }else if( pMem->flags & MEM_Short ){
    pMem->z = pMem->zShort;
  }
  pTos--;
  break;
}

/* Opcode: AggGet * P2 *

** AggReset AggFocus AggNext.  In other words, you must execute
** AggReset first, then zero or more AggFocus operations, then
** zero or more AggNext operations.  You must not execute an AggFocus
** in between an AggNext and an AggReset.
*/
case OP_AggNext: {
  int res;

  CHECK_FOR_INTERRUPT;
  if( p->agg.searching==0 ){
    p->agg.searching = 1;
    if( p->agg.pCsr ){
      rc = sqlite3BtreeFirst(p->agg.pCsr, &res);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
    }else{
      res = 0;
    }
  }else{
    if( p->agg.pCsr ){
      rc = sqlite3BtreeNext(p->agg.pCsr, &res);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
    }else{
      res = 1;
    }
  }

  if( res!=0 ){
    pc = pOp->p2 - 1;
  }else{
    int i;
    sqlite3_context ctx;
    Mem *aMem;

    if( p->agg.pCsr ){
      rc = sqlite3BtreeData(p->agg.pCsr, 0, sizeof(AggElem*),
          (char *)&p->agg.pCurrent);
      if( rc!=SQLITE_OK ) goto abort_due_to_error;
    }
    aMem = p->agg.pCurrent->aMem;
    for(i=0; i<p->agg.nMem; i++){
      int freeCtx;
      if( p->agg.apFunc[i]==0 ) continue;

      if( p->agg.apFunc[i]->xFinalize==0 ) continue;
      ctx.s.flags = MEM_Null;
      ctx.s.z = aMem[i].zShort;
      ctx.pAgg = (void*)aMem[i].z;
      ctx.cnt = aMem[i].i;
      ctx.isStep = 0;
      ctx.pFunc = p->agg.apFunc[i];
      (*p->agg.apFunc[i]->xFinalize)(&ctx);
      aMem[i].z = ctx.pAgg;
      freeCtx = aMem[i].z && aMem[i].z!=aMem[i].zShort;
      if( freeCtx ){
        sqliteFree( aMem[i].z );
      }
      aMem[i] = ctx.s;
      if( aMem[i].flags & MEM_Short ){
        aMem[i].z = aMem[i].zShort;
      }
    }
  }
  break;
}

/* Opcode: Vacuum * * *

*************************************************************************
** 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 1.89 2004/06/27 21:31:40 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

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

void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N);
void sqlite3VdbeDequoteP3(Vdbe*, int addr);
int sqlite3VdbeFindOp(Vdbe*, int, int, int);
VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
int sqlite3VdbeMakeLabel(Vdbe*);
void sqlite3VdbeDelete(Vdbe*);
void sqlite3VdbeMakeReady(Vdbe*,int,int);
int sqlite3VdbeFinalize(Vdbe*);
void sqlite3VdbeResolveLabel(Vdbe*, int);
int sqlite3VdbeCurrentAddr(Vdbe*);
void sqlite3VdbeTrace(Vdbe*,FILE*);
int sqlite3VdbeReset(Vdbe*);
int sqliteVdbeSetVariables(Vdbe*,int,const char**);
void sqlite3VdbeSetNumCols(Vdbe*,int);

  Mem *aStack;        /* The operand stack, except string values */
  Mem *pTos;          /* Top entry in the operand stack */
  Mem **apArg;        /* Arguments to currently executing user function */
  Mem *aColName;      /* Column names to return */
  int nCursor;        /* Number of slots in apCsr[] */
  Cursor **apCsr;     /* One element of this array for each open cursor */
  Sorter *pSort;      /* A linked list of objects to be sorted */
  FILE *pFile;        /* At most one open file handler */
  int nField;         /* Number of file fields */
  char **azField;     /* Data for each file field */
  int nVar;           /* Number of entries in apVar[] */
  Mem *apVar;         /* Values for the OP_Variable opcode. */
  char **azVar;       /* Name of variables */
  int okVar;          /* True if azVar[] has been initialized */
  char *zLine;            /* A single line from the input file */
  int nLineAlloc;         /* Number of spaces allocated for zLine */
  int magic;              /* Magic number for sanity checking */
  int nMem;               /* Number of memory locations currently allocated */
  Mem *aMem;              /* The memory locations */
  Agg agg;                /* Aggregate information */
  int nCallback;          /* Number of callbacks invoked so far */
  Keylist *pList;         /* A list of ROWIDs */
  int keylistStackDepth;  /* The size of the "keylist" stack */

    return SQLITE_MISUSE;
  }
  if( i<1 || i>p->nVar ){
    sqlite3Error(p->db, SQLITE_RANGE, 0);
    return SQLITE_RANGE;
  }
  i--;
  pVar = &p->apVar[i];
  sqlite3VdbeMemRelease(pVar);
  pVar->flags = MEM_Null;
  sqlite3Error(p->db, SQLITE_OK, 0);
  return SQLITE_OK;
}

/*

  Mem *pVar;
  int rc;

  rc = vdbeUnbind(p, i);
  if( rc || zData==0 ){
    return rc;
  }
  pVar = &p->apVar[i-1];
  rc = sqlite3VdbeMemSetStr(pVar, zData, nData, 0, xDel);
  return rc;
}
int sqlite3_bind_double(sqlite3_stmt *pStmt, int i, double rValue){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    sqlite3VdbeMemSetDouble(&p->apVar[i-1], rValue);
  }
  return rc;
}
int sqlite3_bind_int(sqlite3_stmt *p, int i, int iValue){
  return sqlite3_bind_int64(p, i, (i64)iValue);
}
int sqlite3_bind_int64(sqlite3_stmt *pStmt, int i, sqlite_int64 iValue){
  int rc;
  Vdbe *p = (Vdbe *)pStmt;
  rc = vdbeUnbind(p, i);
  if( rc==SQLITE_OK ){
    sqlite3VdbeMemSetInt64(&p->apVar[i-1], iValue);
  }
  return rc;
}
int sqlite3_bind_null(sqlite3_stmt* p, int i){
  return vdbeUnbind((Vdbe *)p, i);
}
int sqlite3_bind_text( 

  Mem *pVar;
  int rc;

  rc = vdbeUnbind(p, i);
  if( rc || zData==0 ){
    return rc;
  }
  pVar = &p->apVar[i-1];
  rc = sqlite3VdbeMemSetStr(pVar, zData, nData, SQLITE_UTF8, xDel);
  if( rc ){
    return rc;
  }
  rc = sqlite3VdbeChangeEncoding(pVar, p->db->enc);
  return rc;
}

  Mem *pVar;
  int rc;

  rc = vdbeUnbind(p, i);
  if( rc || zData==0 ){
    return rc;
  }
  pVar = &p->apVar[i-1];

  rc = sqlite3VdbeMemSetStr(pVar, zData, nData, SQLITE_UTF16NATIVE, xDel);
  if( rc ){
    return rc;
  }
  rc = sqlite3VdbeChangeEncoding(pVar, p->db->enc);
  return rc;

** as allocating stack space and initializing the program counter.
** After the VDBE has be prepped, it can be executed by one or more
** calls to sqlite3VdbeExec().  
*/
void sqlite3VdbeMakeReady(
  Vdbe *p,                       /* The VDBE */
  int nVar,                      /* Number of '?' see in the SQL statement */


  int isExplain                  /* True if the EXPLAIN keywords is present */
){
  int n;

  assert( p!=0 );
  assert( p->magic==VDBE_MAGIC_INIT );

  ** stack.  And the stack never grows on successive executions of the
  ** same loop.  So the total number of instructions is an upper bound
  ** on the maximum stack depth required.
  **
  ** Allocation all the stack space we will ever need.
  */
  if( p->aStack==0 ){
    p->nVar = nVar;
    assert( nVar>=0 );
    n = isExplain ? 10 : p->nOp;
    p->aStack = sqliteMalloc(
      n*(sizeof(p->aStack[0])+sizeof(Mem*))          /* aStack, apArg */
      + p->nVar*sizeof(Mem)                          /* apVar */
      + p->nVar*sizeof(char*)                        /* apVarName */


    );

    p->apArg = (Mem **)&p->aStack[n];
    p->apVar = (Mem *)&p->apArg[n];
    p->azVar = (char**)&p->apVar[p->nVar];
    p->okVar = 0;





    for(n=0; n<p->nVar; n++){
      p->apVar[n].flags = MEM_Null;




    }
  }

#ifdef SQLITE_DEBUG
  if( (p->db->flags & SQLITE_VdbeListing)!=0
    || sqlite3OsFileExists("vdbe_explain")
  ){

}

/*
** Close all cursors
*/
static void closeAllCursors(Vdbe *p){
  int i;

  for(i=0; i<p->nCursor; i++){
    sqlite3VdbeFreeCursor(p->apCsr[i]);

  }
  sqliteFree(p->apCsr);
  p->apCsr = 0;
  p->nCursor = 0;
}

/*
** Clean up the VM after execution.
**
** This routine will automatically close any cursors, lists, and/or
** sorters that were left open.  It also deletes the values of
** variables in the aVar[] array.
*/
static void Cleanup(Vdbe *p){
  int i;
  if( p->aStack ){
    Mem *pTos = p->pTos;
    while( pTos>=p->aStack ){
      sqlite3VdbeMemRelease(pTos);
      pTos--;
    }
    p->pTos = pTos;
  }
  closeAllCursors(p);
  if( p->aMem ){
    for(i=0; i<p->nMem; i++){
      sqlite3VdbeMemRelease(&p->aMem[i]);
    }
  }
  sqliteFree(p->aMem);
  p->aMem = 0;
  p->nMem = 0;
  if( p->pList ){
    sqlite3VdbeKeylistFree(p->pList);
    p->pList = 0;
  }
  sqlite3VdbeSorterReset(p);
  if( p->pFile ){
    if( p->pFile!=stdin ) fclose(p->pFile);
    p->pFile = 0;
  }
  if( p->azField ){
    sqliteFree(p->azField);
    p->azField = 0;
  }
  p->nField = 0;
  if( p->zLine ){
    sqliteFree(p->zLine);
    p->zLine = 0;
  }
  p->nLineAlloc = 0;
  sqlite3VdbeAggReset(0, &p->agg, 0);
  if( p->keylistStack ){
    int ii;
    for(ii = 0; ii < p->keylistStackDepth; ii++){
      sqlite3VdbeKeylistFree(p->keylistStack[ii]);
    }
    sqliteFree(p->keylistStack);

    if( pOp->p3type==P3_VDBEFUNC ){
      VdbeFunc *pVdbeFunc = (VdbeFunc *)pOp->p3;
      sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
      sqliteFree(pVdbeFunc);
    }
  }
  for(i=0; i<p->nVar; i++){
    sqlite3VdbeMemRelease(&p->apVar[i]);
  }
  sqliteFree(p->aOp);
  sqliteFree(p->aLabel);
  sqliteFree(p->aStack);
  if( p->aColName ){
    for(i=0; i<(p->nResColumn)*2; i++){
      sqlite3VdbeMemRelease(&(p->aColName[i]));

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.
**
** $Id: where.c,v 1.111 2004/07/20 18:23:15 drh Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.

  pWInfo = sqliteMalloc( sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
  if( sqlite3_malloc_failed ){
    /* sqliteFree(pWInfo); // Leak memory when malloc fails */
    return 0;
  }
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->peakNTab = pWInfo->savedNTab = pParse->nTab;
  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);

  /* Special case: a WHERE clause that is constant.  Evaluate the
  ** expression and either jump over all of the code or fall thru.
  */
  if( pWhere && (pTabList->nSrc==0 || sqlite3ExprIsConstant(pWhere)) ){
    sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, 1);

    }
    pWInfo->a[i].pIdx = pBestIdx;
    pWInfo->a[i].score = bestScore;
    pWInfo->a[i].bRev = 0;
    loopMask |= mask;
    if( pBestIdx ){
      pWInfo->a[i].iCur = pParse->nTab++;
      pWInfo->peakNTab = pParse->nTab;
    }
  }

  /* Check to see if the ORDER BY clause is or can be satisfied by the
  ** use of an index on the first table.
  */
  if( ppOrderBy && *ppOrderBy && pTabList->nSrc>0 ){

       pSortIdx = findSortingIndex(pParse, pTab, pTabList->a[0].iCursor, 
                                   *ppOrderBy, pIdx, nEqCol, &bRev);
     }
     if( pSortIdx && (pIdx==0 || pIdx==pSortIdx) ){
       if( pIdx==0 ){
         pWInfo->a[0].pIdx = pSortIdx;
         pWInfo->a[0].iCur = pParse->nTab++;
         pWInfo->peakNTab = pParse->nTab;
       }
       pWInfo->a[0].bRev = bRev;
       *ppOrderBy = 0;
     }
  }

  /* Open all tables in the pTabList and all indices used by those tables.

    if( pTab->isTransient || pTab->pSelect ) continue;
    pLevel = &pWInfo->a[i];
    sqlite3VdbeAddOp(v, OP_Close, pTabList->a[i].iCursor, 0);
    if( pLevel->pIdx!=0 ){
      sqlite3VdbeAddOp(v, OP_Close, pLevel->iCur, 0);
    }
  }
#if 0  /* Never reuse a cursor */
  if( pWInfo->pParse->nTab==pWInfo->peakNTab ){
    pWInfo->pParse->nTab = pWInfo->savedNTab;
  }
#endif
  sqliteFree(pWInfo);
  return;
}

# module "crashtest" compiled with the special "os_test.c" backend is used.
# The os_test.c simulates the kind of file corruption that can occur
# when writes are happening at the moment of power loss.
# 
# The special crash-test module with its os_test.c backend only works
# on Unix.
#
# $Id: crash.test,v 1.7 2004/06/28 04:52:31 danielk1977 Exp $

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

# set repeats 100
set repeats 10

  execsql { BEGIN }
  for {set n 0} {$n < 1000} {incr n} {
    execsql "INSERT INTO abc VALUES($n, [expr 2*$n], [expr 3*$n])"
  }
  execsql { COMMIT }
  set ::sig [signature]
  execsql { SELECT sum(a), sum(b), sum(c) from abc }
} {499500 999000 1498500}
do_test crash-2.2 {
  expr [file size test.db] / 1024
} {19}
do_test crash-2.3 {
  crashsql 2 test.db-journal {
    DELETE FROM abc WHERE a < 800;
  }

    signature
  } $sig
  do_test crash-4.1.$i.3 {
    signature2
  } $sig2
} 
set i 0

while {[incr i]} {
  set sig [signature]
  set sig2 [signature2]
  set ::fin 0
  do_test crash-4.2.$i.1 {
     set c [crashsql $i test2.db-journal "
       ATTACH 'test2.db' AS aux;