text: /*
  ** 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.
  **
  *************************************************************************
  ** This file contains routines used for analyzing expressions and
  ** for generating VDBE code that evaluates expressions in SQLite.
  **
  ** $Id$
  */
  #include "sqliteInt.h"
  #include <ctype.h>
  
  /*
  ** Construct a new expression node and return a pointer to it.  Memory
  ** for this node is obtained from sqliteMalloc().  The calling function
  ** is responsible for making sure the node eventually gets freed.
  */
  Expr *sqliteExpr(int op, Expr *pLeft, Expr *pRight, Token *pToken){
    Expr *pNew;
    pNew = sqliteMalloc( sizeof(Expr) );
    if( pNew==0 ){
      /* When malloc fails, we leak memory from pLeft and pRight */
      return 0;
    }
    pNew->op = op;
    pNew->pLeft = pLeft;
    pNew->pRight = pRight;
    if( pToken ){
      assert( pToken->dyn==0 );
      pNew->token = *pToken;
      pNew->span = *pToken;
    }else{
      assert( pNew->token.dyn==0 );
      assert( pNew->token.z==0 );
      assert( pNew->token.n==0 );
      if( pLeft && pRight ){
        sqliteExprSpan(pNew, &pLeft->span, &pRight->span);
      }else{
        pNew->span = pNew->token;
      }
    }
    return pNew;
  }
  
  /*
  ** Set the Expr.span field of the given expression to span all
  ** text between the two given tokens.
  */
  void sqliteExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
    assert( pRight!=0 );
    assert( pLeft!=0 );
    /* Note: pExpr might be NULL due to a prior malloc failure */
    if( pExpr && pRight->z && pLeft->z ){
      if( pLeft->dyn==0 && pRight->dyn==0 ){
        pExpr->span.z = pLeft->z;
        pExpr->span.n = pRight->n + Addr(pRight->z) - Addr(pLeft->z);
      }else{
        pExpr->span.z = 0;
      }
    }
  }
  
  /*
  ** Construct a new expression node for a function with multiple
  ** arguments.
  */
  Expr *sqliteExprFunction(ExprList *pList, Token *pToken){
    Expr *pNew;
    pNew = sqliteMalloc( sizeof(Expr) );
    if( pNew==0 ){
      /* sqliteExprListDelete(pList); // Leak pList when malloc fails */
      return 0;
    }
    pNew->op = TK_FUNCTION;
    pNew->pList = pList;
    if( pToken ){
      assert( pToken->dyn==0 );
      pNew->token = *pToken;
    }else{
      pNew->token.z = 0;
    }
    pNew->span = pNew->token;
    return pNew;
  }
  
  /*
  ** Recursively delete an expression tree.
  */
  void sqliteExprDelete(Expr *p){
    if( p==0 ) return;
    if( p->span.dyn ) sqliteFree((char*)p->span.z);
    if( p->token.dyn ) sqliteFree((char*)p->token.z);
    sqliteExprDelete(p->pLeft);
    sqliteExprDelete(p->pRight);
    sqliteExprListDelete(p->pList);
    sqliteSelectDelete(p->pSelect);
    sqliteFree(p);
  }
  
  
  /*
  ** The following group of routines make deep copies of expressions,
  ** expression lists, ID lists, and select statements.  The copies can
  ** be deleted (by being passed to their respective ...Delete() routines)
  ** without effecting the originals.
  **
  ** The expression list, ID, and source lists return by sqliteExprListDup(),
  ** sqliteIdListDup(), and sqliteSrcListDup() can not be further expanded 
  ** by subsequent calls to sqlite*ListAppend() routines.
  **
  ** Any tables that the SrcList might point to are not duplicated.
  */
  Expr *sqliteExprDup(Expr *p){
    Expr *pNew;
    if( p==0 ) return 0;
    pNew = sqliteMallocRaw( sizeof(*p) );
    if( pNew==0 ) return 0;
    memcpy(pNew, p, sizeof(*pNew));
    if( p->token.z!=0 ){
      pNew->token.z = sqliteStrDup(p->token.z);
      pNew->token.dyn = 1;
    }else{
      assert( pNew->token.z==0 );
    }
    pNew->span.z = 0;
    pNew->pLeft = sqliteExprDup(p->pLeft);
    pNew->pRight = sqliteExprDup(p->pRight);
    pNew->pList = sqliteExprListDup(p->pList);
    pNew->pSelect = sqliteSelectDup(p->pSelect);
    return pNew;
  }
  void sqliteTokenCopy(Token *pTo, Token *pFrom){
    if( pTo->dyn ) sqliteFree((char*)pTo->z);
    if( pFrom->z ){
      pTo->n = pFrom->n;
      pTo->z = sqliteStrNDup(pFrom->z, pFrom->n);
      pTo->dyn = 1;
    }else{
      pTo->z = 0;
    }
  }
  ExprList *sqliteExprListDup(ExprList *p){
    ExprList *pNew;
    struct ExprList_item *pItem;
    int i;
    if( p==0 ) return 0;
    pNew = sqliteMalloc( sizeof(*pNew) );
    if( pNew==0 ) return 0;
    pNew->nExpr = pNew->nAlloc = p->nExpr;
    pNew->a = pItem = sqliteMalloc( p->nExpr*sizeof(p->a[0]) );
    if( pItem==0 ) return 0;  /* Leaks memory after a malloc failure */
    for(i=0; i<p->nExpr; i++, pItem++){
      Expr *pNewExpr, *pOldExpr;
      pItem->pExpr = pNewExpr = sqliteExprDup(pOldExpr = p->a[i].pExpr);
      if( pOldExpr->span.z!=0 && pNewExpr ){
        /* Always make a copy of the span for top-level expressions in the
        ** expression list.  The logic in SELECT processing that determines
        ** the names of columns in the result set needs this information */
        sqliteTokenCopy(&pNewExpr->span, &pOldExpr->span);
      }
      assert( pNewExpr==0 || pNewExpr->span.z!=0 
              || pOldExpr->span.z==0 || sqlite_malloc_failed );
      pItem->zName = sqliteStrDup(p->a[i].zName);
      pItem->sortOrder = p->a[i].sortOrder;
      pItem->isAgg = p->a[i].isAgg;
      pItem->done = 0;
    }
    return pNew;
  }
  SrcList *sqliteSrcListDup(SrcList *p){
    SrcList *pNew;
    int i;
    int nByte;
    if( p==0 ) return 0;
    nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
    pNew = sqliteMallocRaw( nByte );
    if( pNew==0 ) return 0;
    pNew->nSrc = pNew->nAlloc = p->nSrc;
    for(i=0; i<p->nSrc; i++){
      struct SrcList_item *pNewItem = &pNew->a[i];
      struct SrcList_item *pOldItem = &p->a[i];
      pNewItem->zDatabase = sqliteStrDup(pOldItem->zDatabase);
      pNewItem->zName = sqliteStrDup(pOldItem->zName);
      pNewItem->zAlias = sqliteStrDup(pOldItem->zAlias);
      pNewItem->jointype = pOldItem->jointype;
      pNewItem->iCursor = pOldItem->iCursor;
      pNewItem->pTab = 0;
      pNewItem->pSelect = sqliteSelectDup(pOldItem->pSelect);
      pNewItem->pOn = sqliteExprDup(pOldItem->pOn);
      pNewItem->pUsing = sqliteIdListDup(pOldItem->pUsing);
    }
    return pNew;
  }
  IdList *sqliteIdListDup(IdList *p){
    IdList *pNew;
    int i;
    if( p==0 ) return 0;
    pNew = sqliteMallocRaw( sizeof(*pNew) );
    if( pNew==0 ) return 0;
    pNew->nId = pNew->nAlloc = p->nId;
    pNew->a = sqliteMallocRaw( p->nId*sizeof(p->a[0]) );
    if( pNew->a==0 ) return 0;
    for(i=0; i<p->nId; i++){
      struct IdList_item *pNewItem = &pNew->a[i];
      struct IdList_item *pOldItem = &p->a[i];
      pNewItem->zName = sqliteStrDup(pOldItem->zName);
      pNewItem->idx = pOldItem->idx;
    }
    return pNew;
  }
  Select *sqliteSelectDup(Select *p){
    Select *pNew;
    if( p==0 ) return 0;
    pNew = sqliteMallocRaw( sizeof(*p) );
    if( pNew==0 ) return 0;
    pNew->isDistinct = p->isDistinct;
    pNew->pEList = sqliteExprListDup(p->pEList);
    pNew->pSrc = sqliteSrcListDup(p->pSrc);
    pNew->pWhere = sqliteExprDup(p->pWhere);
    pNew->pGroupBy = sqliteExprListDup(p->pGroupBy);
    pNew->pHaving = sqliteExprDup(p->pHaving);
    pNew->pOrderBy = sqliteExprListDup(p->pOrderBy);
    pNew->op = p->op;
    pNew->pPrior = sqliteSelectDup(p->pPrior);
    pNew->nLimit = p->nLimit;
    pNew->nOffset = p->nOffset;
    pNew->zSelect = 0;
    pNew->iLimit = -1;
    pNew->iOffset = -1;
    return pNew;
  }
  
  
  /*
  ** Add a new element to the end of an expression list.  If pList is
  ** initially NULL, then create a new expression list.
  */
  ExprList *sqliteExprListAppend(ExprList *pList, Expr *pExpr, Token *pName){
    if( pList==0 ){
      pList = sqliteMalloc( sizeof(ExprList) );
      if( pList==0 ){
        /* sqliteExprDelete(pExpr); // Leak memory if malloc fails */
        return 0;
      }
      assert( pList->nAlloc==0 );
    }
    if( pList->nAlloc<=pList->nExpr ){
      pList->nAlloc = pList->nAlloc*2 + 4;
      pList->a = sqliteRealloc(pList->a, pList->nAlloc*sizeof(pList->a[0]));
      if( pList->a==0 ){
        /* sqliteExprDelete(pExpr); // Leak memory if malloc fails */
        pList->nExpr = pList->nAlloc = 0;
        return pList;
      }
    }
    assert( pList->a!=0 );
    if( pExpr || pName ){
      struct ExprList_item *pItem = &pList->a[pList->nExpr++];
      memset(pItem, 0, sizeof(*pItem));
      pItem->pExpr = pExpr;
      if( pName ){
        sqliteSetNString(&pItem->zName, pName->z, pName->n, 0);
        sqliteDequote(pItem->zName);
      }
    }
    return pList;
  }
  
  /*
  ** Delete an entire expression list.
  */
  void sqliteExprListDelete(ExprList *pList){
    int i;
    if( pList==0 ) return;
    assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
    assert( pList->nExpr<=pList->nAlloc );
    for(i=0; i<pList->nExpr; i++){
      sqliteExprDelete(pList->a[i].pExpr);
      sqliteFree(pList->a[i].zName);
    }
    sqliteFree(pList->a);
    sqliteFree(pList);
  }
  
  /*
  ** Walk an expression tree.  Return 1 if the expression is constant
  ** and 0 if it involves variables.
  **
  ** For the purposes of this function, a double-quoted string (ex: "abc")
  ** is considered a variable but a single-quoted string (ex: 'abc') is
  ** a constant.
  */
  int sqliteExprIsConstant(Expr *p){
    switch( p->op ){
      case TK_ID:
      case TK_COLUMN:
      case TK_DOT:
      case TK_FUNCTION:
        return 0;
      case TK_NULL:
      case TK_STRING:
      case TK_INTEGER:
      case TK_FLOAT:
      case TK_VARIABLE:
        return 1;
      default: {
        if( p->pLeft && !sqliteExprIsConstant(p->pLeft) ) return 0;
        if( p->pRight && !sqliteExprIsConstant(p->pRight) ) return 0;
        if( p->pList ){
          int i;
          for(i=0; i<p->pList->nExpr; i++){
            if( !sqliteExprIsConstant(p->pList->a[i].pExpr) ) return 0;
          }
        }
        return p->pLeft!=0 || p->pRight!=0 || (p->pList && p->pList->nExpr>0);
      }
    }
    return 0;
  }
  
  /*
  ** If the given expression codes a constant integer that is small enough
  ** to fit in a 32-bit integer, return 1 and put the value of the integer
  ** in *pValue.  If the expression is not an integer or if it is too big
  ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
  */
  int sqliteExprIsInteger(Expr *p, int *pValue){
    switch( p->op ){
      case TK_INTEGER: {
        if( sqliteFitsIn32Bits(p->token.z) ){
          *pValue = atoi(p->token.z);
          return 1;
        }
        break;
      }
      case TK_STRING: {
        const char *z = p->token.z;
        int n = p->token.n;
        if( n>0 && z[0]=='-' ){ z++; n--; }
        while( n>0 && *z && isdigit(*z) ){ z++; n--; }
        if( n==0 && sqliteFitsIn32Bits(p->token.z) ){
          *pValue = atoi(p->token.z);
          return 1;
        }
        break;
      }
      case TK_UPLUS: {
        return sqliteExprIsInteger(p->pLeft, pValue);
      }
      case TK_UMINUS: {
        int v;
        if( sqliteExprIsInteger(p->pLeft, &v) ){
          *pValue = -v;
          return 1;
        }
        break;
      }
      default: break;
    }
    return 0;
  }
  
  /*
  ** Return TRUE if the given string is a row-id column name.
  */
  int sqliteIsRowid(const char *z){
    if( sqliteStrICmp(z, "_ROWID_")==0 ) return 1;
    if( sqliteStrICmp(z, "ROWID")==0 ) return 1;
    if( sqliteStrICmp(z, "OID")==0 ) return 1;
    return 0;
  }
  
  /*
  ** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
  ** that name in the set of source tables in pSrcList and make the pExpr 
  ** expression node refer back to that source column.  The following changes
  ** are made to pExpr:
  **
  **    pExpr->iDb           Set the index in db->aDb[] of the database holding
  **                         the table.
  **    pExpr->iTable        Set to the cursor number for the table obtained
  **                         from pSrcList.
  **    pExpr->iColumn       Set to the column number within the table.
  **    pExpr->dataType      Set to the appropriate data type for the column.
  **    pExpr->op            Set to TK_COLUMN.
  **    pExpr->pLeft         Any expression this points to is deleted
  **    pExpr->pRight        Any expression this points to is deleted.
  **
  ** The pDbToken is the name of the database (the "X").  This value may be
  ** NULL meaning that name is of the form Y.Z or Z.  Any available database
  ** can be used.  The pTableToken is the name of the table (the "Y").  This
  ** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
  ** means that the form of the name is Z and that columns from any table
  ** can be used.
  **
  ** If the name cannot be resolved unambiguously, leave an error message
  ** in pParse and return non-zero.  Return zero on success.
  */
  static int lookupName(
    Parse *pParse,      /* The parsing context */
    Token *pDbToken,     /* Name of the database containing table, or NULL */
    Token *pTableToken,  /* Name of table containing column, or NULL */
    Token *pColumnToken, /* Name of the column. */
    SrcList *pSrcList,   /* List of tables used to resolve column names */
    ExprList *pEList,    /* List of expressions used to resolve "AS" */
    Expr *pExpr          /* Make this EXPR node point to the selected column */
  ){
    char *zDb = 0;       /* Name of the database.  The "X" in X.Y.Z */
    char *zTab = 0;      /* Name of the table.  The "Y" in X.Y.Z or Y.Z */
    char *zCol = 0;      /* Name of the column.  The "Z" */
    int i, j;            /* Loop counters */
    int cnt = 0;         /* Number of matching column names */
    int cntTab = 0;      /* Number of matching table names */
    sqlite *db = pParse->db;  /* The database */
  
    assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
    if( pDbToken && pDbToken->z ){
      zDb = sqliteStrNDup(pDbToken->z, pDbToken->n);
      sqliteDequote(zDb);
    }else{
      zDb = 0;
    }
    if( pTableToken && pTableToken->z ){
      zTab = sqliteStrNDup(pTableToken->z, pTableToken->n);
      sqliteDequote(zTab);
    }else{
      assert( zDb==0 );
      zTab = 0;
    }
    zCol = sqliteStrNDup(pColumnToken->z, pColumnToken->n);
    sqliteDequote(zCol);
    if( sqlite_malloc_failed ){
      return 1;  /* Leak memory (zDb and zTab) if malloc fails */
    }
    assert( zTab==0 || pEList==0 );
  
    pExpr->iTable = -1;
    for(i=0; i<pSrcList->nSrc; i++){
      struct SrcList_item *pItem = &pSrcList->a[i];
      Table *pTab = pItem->pTab;
      Column *pCol;
  
      if( pTab==0 ) continue;
      assert( pTab->nCol>0 );
      if( zTab ){
        if( pItem->zAlias ){
          char *zTabName = pItem->zAlias;
          if( sqliteStrICmp(zTabName, zTab)!=0 ) continue;
        }else{
          char *zTabName = pTab->zName;
          if( zTabName==0 || sqliteStrICmp(zTabName, zTab)!=0 ) continue;
          if( zDb!=0 && sqliteStrICmp(db->aDb[pTab->iDb].zName, zDb)!=0 ){
            continue;
          }
        }
      }
      if( 0==(cntTab++) ){
        pExpr->iTable = pItem->iCursor;
        pExpr->iDb = pTab->iDb;
      }
      for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
        if( sqliteStrICmp(pCol->zName, zCol)==0 ){
          cnt++;
          pExpr->iTable = pItem->iCursor;
          pExpr->iDb = pTab->iDb;
          /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
          pExpr->iColumn = j==pTab->iPKey ? -1 : j;
          pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
          break;
        }
      }
    }
  
    /* If we have not already resolved the name, then maybe 
    ** it is a new.* or old.* trigger argument reference
    */
    if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
      TriggerStack *pTriggerStack = pParse->trigStack;
      Table *pTab = 0;
      if( pTriggerStack->newIdx != -1 && sqliteStrICmp("new", zTab) == 0 ){
        pExpr->iTable = pTriggerStack->newIdx;
        assert( pTriggerStack->pTab );
        pTab = pTriggerStack->pTab;
      }else if( pTriggerStack->oldIdx != -1 && sqliteStrICmp("old", zTab) == 0 ){
        pExpr->iTable = pTriggerStack->oldIdx;
        assert( pTriggerStack->pTab );
        pTab = pTriggerStack->pTab;
      }
  
      if( pTab ){ 
        int j;
        Column *pCol = pTab->aCol;
        
        pExpr->iDb = pTab->iDb;
        cntTab++;
        for(j=0; j < pTab->nCol; j++, pCol++) {
          if( sqliteStrICmp(pCol->zName, zCol)==0 ){
            cnt++;
            pExpr->iColumn = j==pTab->iPKey ? -1 : j;
            pExpr->dataType = pCol->sortOrder & SQLITE_SO_TYPEMASK;
            break;
          }
        }
      }
    }
  
    /*
    ** Perhaps the name is a reference to the ROWID
    */
    if( cnt==0 && cntTab==1 && sqliteIsRowid(zCol) ){
      cnt = 1;
      pExpr->iColumn = -1;
      pExpr->dataType = SQLITE_SO_NUM;
    }
  
    /*
    ** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
    ** might refer to an result-set alias.  This happens, for example, when
    ** we are resolving names in the WHERE clause of the following command:
    **
    **     SELECT a+b AS x FROM table WHERE x<10;
    **
    ** In cases like this, replace pExpr with a copy of the expression that
    ** forms the result set entry ("a+b" in the example) and return immediately.
    ** Note that the expression in the result set should have already been
    ** resolved by the time the WHERE clause is resolved.
    */
    if( cnt==0 && pEList!=0 ){
      for(j=0; j<pEList->nExpr; j++){
        char *zAs = pEList->a[j].zName;
        if( zAs!=0 && sqliteStrICmp(zAs, zCol)==0 ){
          assert( pExpr->pLeft==0 && pExpr->pRight==0 );
          pExpr->op = TK_AS;
          pExpr->iColumn = j;
          pExpr->pLeft = sqliteExprDup(pEList->a[j].pExpr);
          sqliteFree(zCol);
          assert( zTab==0 && zDb==0 );
          return 0;
        }
      } 
    }
  
    /*
    ** If X and Y are NULL (in other words if only the column name Z is
    ** supplied) and the value of Z is enclosed in double-quotes, then
    ** Z is a string literal if it doesn't match any column names.  In that
    ** case, we need to return right away and not make any changes to
    ** pExpr.
    */
    if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
      sqliteFree(zCol);
      return 0;
    }
  
    /*
    ** cnt==0 means there was not match.  cnt>1 means there were two or
    ** more matches.  Either way, we have an error.
    */
    if( cnt!=1 ){
      char *z = 0;
      char *zErr;
      zErr = cnt==0 ? "no such column: %s" : "ambiguous column name: %s";
      if( zDb ){
        sqliteSetString(&z, zDb, ".", zTab, ".", zCol, 0);
      }else if( zTab ){
        sqliteSetString(&z, zTab, ".", zCol, 0);
      }else{
        z = sqliteStrDup(zCol);
      }
      sqliteErrorMsg(pParse, zErr, z);
      sqliteFree(z);
    }
  
    /* Clean up and return
    */
    sqliteFree(zDb);
    sqliteFree(zTab);
    sqliteFree(zCol);
    sqliteExprDelete(pExpr->pLeft);
    pExpr->pLeft = 0;
    sqliteExprDelete(pExpr->pRight);
    pExpr->pRight = 0;
    pExpr->op = TK_COLUMN;
    sqliteAuthRead(pParse, pExpr, pSrcList);
    return cnt!=1;
  }
  
  /*
  ** This routine walks an expression tree and resolves references to
  ** table columns.  Nodes of the form ID.ID or ID resolve into an
  ** index to the table in the table list and a column offset.  The 
  ** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
  ** value is changed to the index of the referenced table in pTabList
  ** plus the "base" value.  The base value will ultimately become the
  ** VDBE cursor number for a cursor that is pointing into the referenced
  ** table.  The Expr.iColumn value is changed to the index of the column 
  ** of the referenced table.  The Expr.iColumn value for the special
  ** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
  ** alias for ROWID.
  **
  ** We also check for instances of the IN operator.  IN comes in two
  ** forms:
  **
  **           expr IN (exprlist)
  ** and
  **           expr IN (SELECT ...)
  **
  ** The first form is handled by creating a set holding the list
  ** of allowed values.  The second form causes the SELECT to generate 
  ** a temporary table.
  **
  ** This routine also looks for scalar SELECTs that are part of an expression.
  ** If it finds any, it generates code to write the value of that select
  ** into a memory cell.
  **
  ** Unknown columns or tables provoke an error.  The function returns
  ** the number of errors seen and leaves an error message on pParse->zErrMsg.
  */
  int sqliteExprResolveIds(
    Parse *pParse,     /* The parser context */
    SrcList *pSrcList, /* List of tables used to resolve column names */
    ExprList *pEList,  /* List of expressions used to resolve "AS" */
    Expr *pExpr        /* The expression to be analyzed. */
  ){
    int i;
  
    if( pExpr==0 || pSrcList==0 ) return 0;
    for(i=0; i<pSrcList->nSrc; i++){
      assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab );
    }
    switch( pExpr->op ){
      /* Double-quoted strings (ex: "abc") are used as identifiers if
      ** possible.  Otherwise they remain as strings.  Single-quoted
      ** strings (ex: 'abc') are always string literals.
      */
      case TK_STRING: {
        if( pExpr->token.z[0]=='\'' ) break;
        /* Fall thru into the TK_ID case if this is a double-quoted string */
      }
      /* A lone identifier is the name of a columnd.
      */
      case TK_ID: {
        if( lookupName(pParse, 0, 0, &pExpr->token, pSrcList, pEList, pExpr) ){
          return 1;
        }
        break; 
      }
    
      /* A table name and column name:     ID.ID
      ** Or a database, table and column:  ID.ID.ID
      */
      case TK_DOT: {
        Token *pColumn;
        Token *pTable;
        Token *pDb;
        Expr *pRight;
  
        pRight = pExpr->pRight;
        if( pRight->op==TK_ID ){
          pDb = 0;
          pTable = &pExpr->pLeft->token;
          pColumn = &pRight->token;
        }else{
          assert( pRight->op==TK_DOT );
          pDb = &pExpr->pLeft->token;
          pTable = &pRight->pLeft->token;
          pColumn = &pRight->pRight->token;
        }
        if( lookupName(pParse, pDb, pTable, pColumn, pSrcList, 0, pExpr) ){
          return 1;
        }
        break;
      }
  
      case TK_IN: {
        Vdbe *v = sqliteGetVdbe(pParse);
        if( v==0 ) return 1;
        if( sqliteExprResolveIds(pParse, pSrcList, pEList, pExpr->pLeft) ){
          return 1;
        }
        if( pExpr->pSelect ){
          /* Case 1:     expr IN (SELECT ...)
          **
          ** Generate code to write the results of the select into a temporary
          ** table.  The cursor number of the temporary table has already
          ** been put in iTable by sqliteExprResolveInSelect().
          */
          pExpr->iTable = pParse->nTab++;
          sqliteVdbeAddOp(v, OP_OpenTemp, pExpr->iTable, 1);
          sqliteSelect(pParse, pExpr->pSelect, SRT_Set, pExpr->iTable, 0,0,0);
        }else if( pExpr->pList ){
          /* Case 2:     expr IN (exprlist)
          **
          ** Create a set to put the exprlist values in.  The Set id is stored
          ** in iTable.
          */
          int i, iSet;
          for(i=0; i<pExpr->pList->nExpr; i++){
            Expr *pE2 = pExpr->pList->a[i].pExpr;
            if( !sqliteExprIsConstant(pE2) ){
              sqliteErrorMsg(pParse,
                "right-hand side of IN operator must be constant");
              return 1;
            }
            if( sqliteExprCheck(pParse, pE2, 0, 0) ){
              return 1;
            }
          }
          iSet = pExpr->iTable = pParse->nSet++;
          for(i=0; i<pExpr->pList->nExpr; i++){
            Expr *pE2 = pExpr->pList->a[i].pExpr;
            switch( pE2->op ){
              case TK_FLOAT:
              case TK_INTEGER:
              case TK_STRING: {
                int addr;
                assert( pE2->token.z );
                addr = sqliteVdbeOp3(v, OP_SetInsert, iSet, 0,
                                    pE2->token.z, pE2->token.n);
                sqliteVdbeDequoteP3(v, addr);
                break;
              }
              default: {
                sqliteExprCode(pParse, pE2);
                sqliteVdbeAddOp(v, OP_SetInsert, iSet, 0);
                break;
              }
            }
          }
        }
        break;
      }
  
      case TK_SELECT: {
        /* This has to be a scalar SELECT.  Generate code to put the
        ** value of this select in a memory cell and record the number
        ** of the memory cell in iColumn.
        */
        pExpr->iColumn = pParse->nMem++;
        if( sqliteSelect(pParse, pExpr->pSelect, SRT_Mem, pExpr->iColumn,0,0,0) ){
          return 1;
        }
        break;
      }
  
      /* For all else, just recursively walk the tree */
      default: {
        if( pExpr->pLeft
        && sqliteExprResolveIds(pParse, pSrcList, pEList, pExpr->pLeft) ){
          return 1;
        }
        if( pExpr->pRight 
        && sqliteExprResolveIds(pParse, pSrcList, pEList, pExpr->pRight) ){
          return 1;
        }
        if( pExpr->pList ){
          int i;
          ExprList *pList = pExpr->pList;
          for(i=0; i<pList->nExpr; i++){
            Expr *pArg = pList->a[i].pExpr;
            if( sqliteExprResolveIds(pParse, pSrcList, pEList, pArg) ){
              return 1;
            }
          }
        }
      }
    }
    return 0;
  }
  
  /*
  ** pExpr is a node that defines a function of some kind.  It might
  ** be a syntactic function like "count(x)" or it might be a function
  ** that implements an operator, like "a LIKE b".  
  **
  ** This routine makes *pzName point to the name of the function and 
  ** *pnName hold the number of characters in the function name.
  */
  static void getFunctionName(Expr *pExpr, const char **pzName, int *pnName){
    switch( pExpr->op ){
      case TK_FUNCTION: {
        *pzName = pExpr->token.z;
        *pnName = pExpr->token.n;
        break;
      }
      case TK_LIKE: {
        *pzName = "like";
        *pnName = 4;
        break;
      }
      case TK_GLOB: {
        *pzName = "glob";
        *pnName = 4;
        break;
      }
      default: {
        *pzName = "can't happen";
        *pnName = 12;
        break;
      }
    }
  }
  
  /*
  ** Error check the functions in an expression.  Make sure all
  ** function names are recognized and all functions have the correct
  ** number of arguments.  Leave an error message in pParse->zErrMsg
  ** if anything is amiss.  Return the number of errors.
  **
  ** if pIsAgg is not null and this expression is an aggregate function
  ** (like count(*) or max(value)) then write a 1 into *pIsAgg.
  */
  int sqliteExprCheck(Parse *pParse, Expr *pExpr, int allowAgg, int *pIsAgg){
    int nErr = 0;
    if( pExpr==0 ) return 0;
    switch( pExpr->op ){
      case TK_GLOB:
      case TK_LIKE:
      case TK_FUNCTION: {
        int n = pExpr->pList ? pExpr->pList->nExpr : 0;  /* Number of arguments */
        int no_such_func = 0;       /* True if no such function exists */
        int wrong_num_args = 0;     /* True if wrong number of arguments */
        int is_agg = 0;             /* True if is an aggregate function */
        int i;
        int nId;                    /* Number of characters in function name */
        const char *zId;            /* The function name. */
        FuncDef *pDef;
  
        getFunctionName(pExpr, &zId, &nId);
        pDef = sqliteFindFunction(pParse->db, zId, nId, n, 0);
        if( pDef==0 ){
          pDef = sqliteFindFunction(pParse->db, zId, nId, -1, 0);
          if( pDef==0 ){
            no_such_func = 1;
          }else{
            wrong_num_args = 1;
          }
        }else{
          is_agg = pDef->xFunc==0;
        }
        if( is_agg && !allowAgg ){
          sqliteErrorMsg(pParse, "misuse of aggregate function %.*s()", nId, zId);
          nErr++;
          is_agg = 0;
        }else if( no_such_func ){
          sqliteErrorMsg(pParse, "no such function: %.*s", nId, zId);
          nErr++;
        }else if( wrong_num_args ){
          sqliteErrorMsg(pParse,"wrong number of arguments to function %.*s()",
               nId, zId);
          nErr++;
        }
        if( is_agg ){
          pExpr->op = TK_AGG_FUNCTION;
          if( pIsAgg ) *pIsAgg = 1;
        }
        for(i=0; nErr==0 && i<n; i++){
          nErr = sqliteExprCheck(pParse, pExpr->pList->a[i].pExpr,
                                 allowAgg && !is_agg, pIsAgg);
        }
        if( pDef==0 ){
          /* Already reported an error */
        }else if( pDef->dataType>=0 ){
          if( pDef->dataType<n ){
            pExpr->dataType = 
               sqliteExprType(pExpr->pList->a[pDef->dataType].pExpr);
          }else{
            pExpr->dataType = SQLITE_SO_NUM;
          }
        }else if( pDef->dataType==SQLITE_ARGS ){
          pDef->dataType = SQLITE_SO_TEXT;
          for(i=0; i<n; i++){
            if( sqliteExprType(pExpr->pList->a[i].pExpr)==SQLITE_SO_NUM ){
              pExpr->dataType = SQLITE_SO_NUM;
              break;
            }
          }
        }else if( pDef->dataType==SQLITE_NUMERIC ){
          pExpr->dataType = SQLITE_SO_NUM;
        }else{
          pExpr->dataType = SQLITE_SO_TEXT;
        }
      }
      default: {
        if( pExpr->pLeft ){
          nErr = sqliteExprCheck(pParse, pExpr->pLeft, allowAgg, pIsAgg);
        }
        if( nErr==0 && pExpr->pRight ){
          nErr = sqliteExprCheck(pParse, pExpr->pRight, allowAgg, pIsAgg);
        }
        if( nErr==0 && pExpr->pList ){
          int n = pExpr->pList->nExpr;
          int i;
          for(i=0; nErr==0 && i<n; i++){
            Expr *pE2 = pExpr->pList->a[i].pExpr;
            nErr = sqliteExprCheck(pParse, pE2, allowAgg, pIsAgg);
          }
        }
        break;
      }
    }
    return nErr;
  }
  
  /*
  ** Return either SQLITE_SO_NUM or SQLITE_SO_TEXT to indicate whether the
  ** given expression should sort as numeric values or as text.
  **
  ** The sqliteExprResolveIds() and sqliteExprCheck() routines must have
  ** both been called on the expression before it is passed to this routine.
  */
  int sqliteExprType(Expr *p){
    if( p==0 ) return SQLITE_SO_NUM;
    while( p ) switch( p->op ){
      case TK_PLUS:
      case TK_MINUS:
      case TK_STAR:
      case TK_SLASH:
      case TK_AND:
      case TK_OR:
      case TK_ISNULL:
      case TK_NOTNULL:
      case TK_NOT:
      case TK_UMINUS:
      case TK_UPLUS:
      case TK_BITAND:
      case TK_BITOR:
      case TK_BITNOT:
      case TK_LSHIFT:
      case TK_RSHIFT:
      case TK_REM:
      case TK_INTEGER:
      case TK_FLOAT:
      case TK_IN:
      case TK_BETWEEN:
      case TK_GLOB:
      case TK_LIKE:
        return SQLITE_SO_NUM;
  
      case TK_STRING:
      case TK_NULL:
      case TK_CONCAT:
      case TK_VARIABLE:
        return SQLITE_SO_TEXT;
  
      case TK_LT:
      case TK_LE:
      case TK_GT:
      case TK_GE:
      case TK_NE:
      case TK_EQ:
        if( sqliteExprType(p->pLeft)==SQLITE_SO_NUM ){
          return SQLITE_SO_NUM;
        }
        p = p->pRight;
        break;
  
      case TK_AS:
        p = p->pLeft;
        break;
  
      case TK_COLUMN:
      case TK_FUNCTION:
      case TK_AGG_FUNCTION:
        return p->dataType;
  
      case TK_SELECT:
        assert( p->pSelect );
        assert( p->pSelect->pEList );
        assert( p->pSelect->pEList->nExpr>0 );
        p = p->pSelect->pEList->a[0].pExpr;
        break;
  
      case TK_CASE: {
        if( p->pRight && sqliteExprType(p->pRight)==SQLITE_SO_NUM ){
          return SQLITE_SO_NUM;
        }
        if( p->pList ){
          int i;
          ExprList *pList = p->pList;
          for(i=1; i<pList->nExpr; i+=2){
            if( sqliteExprType(pList->a[i].pExpr)==SQLITE_SO_NUM ){
              return SQLITE_SO_NUM;
            }
          }
        }
        return SQLITE_SO_TEXT;
      }
  
      default:
        assert( p->op==TK_ABORT );  /* Can't Happen */
        break;
    }
    return SQLITE_SO_NUM;
  }
  
  /*
  ** Generate code into the current Vdbe to evaluate the given
  ** expression and leave the result on the top of stack.
  */
  void sqliteExprCode(Parse *pParse, Expr *pExpr){
    Vdbe *v = pParse->pVdbe;
    int op;
    if( v==0 || pExpr==0 ) return;
    switch( pExpr->op ){
      case TK_PLUS:     op = OP_Add;      break;
      case TK_MINUS:    op = OP_Subtract; break;
      case TK_STAR:     op = OP_Multiply; break;
      case TK_SLASH:    op = OP_Divide;   break;
      case TK_AND:      op = OP_And;      break;
      case TK_OR:       op = OP_Or;       break;
      case TK_LT:       op = OP_Lt;       break;
      case TK_LE:       op = OP_Le;       break;
      case TK_GT:       op = OP_Gt;       break;
      case TK_GE:       op = OP_Ge;       break;
      case TK_NE:       op = OP_Ne;       break;
      case TK_EQ:       op = OP_Eq;       break;
      case TK_ISNULL:   op = OP_IsNull;   break;
      case TK_NOTNULL:  op = OP_NotNull;  break;
      case TK_NOT:      op = OP_Not;      break;
      case TK_UMINUS:   op = OP_Negative; break;
      case TK_BITAND:   op = OP_BitAnd;   break;
      case TK_BITOR:    op = OP_BitOr;    break;
      case TK_BITNOT:   op = OP_BitNot;   break;
      case TK_LSHIFT:   op = OP_ShiftLeft;  break;
      case TK_RSHIFT:   op = OP_ShiftRight; break;
      case TK_REM:      op = OP_Remainder;  break;
      default: break;
    }
    switch( pExpr->op ){
      case TK_COLUMN: {
        if( pParse->useAgg ){
          sqliteVdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
        }else if( pExpr->iColumn>=0 ){
          sqliteVdbeAddOp(v, OP_Column, pExpr->iTable, pExpr->iColumn);
        }else{
          sqliteVdbeAddOp(v, OP_Recno, pExpr->iTable, 0);
        }
        break;
      }
      case TK_STRING:
      case TK_FLOAT:
      case TK_INTEGER: {
        if( pExpr->op==TK_INTEGER && sqliteFitsIn32Bits(pExpr->token.z) ){
          sqliteVdbeAddOp(v, OP_Integer, atoi(pExpr->token.z), 0);
        }else{
          sqliteVdbeAddOp(v, OP_String, 0, 0);
        }
        assert( pExpr->token.z );
        sqliteVdbeChangeP3(v, -1, pExpr->token.z, pExpr->token.n);
        sqliteVdbeDequoteP3(v, -1);
        break;
      }
      case TK_NULL: {
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        break;
      }
      case TK_VARIABLE: {
        sqliteVdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
        break;
      }
      case TK_LT:
      case TK_LE:
      case TK_GT:
      case TK_GE:
      case TK_NE:
      case TK_EQ: {
        if( pParse->db->file_format>=4 && sqliteExprType(pExpr)==SQLITE_SO_TEXT ){
          op += 6;  /* Convert numeric opcodes to text opcodes */
        }
        /* Fall through into the next case */
      }
      case TK_AND:
      case TK_OR:
      case TK_PLUS:
      case TK_STAR:
      case TK_MINUS:
      case TK_REM:
      case TK_BITAND:
      case TK_BITOR:
      case TK_SLASH: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteExprCode(pParse, pExpr->pRight);
        sqliteVdbeAddOp(v, op, 0, 0);
        break;
      }
      case TK_LSHIFT:
      case TK_RSHIFT: {
        sqliteExprCode(pParse, pExpr->pRight);
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, op, 0, 0);
        break;
      }
      case TK_CONCAT: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteExprCode(pParse, pExpr->pRight);
        sqliteVdbeAddOp(v, OP_Concat, 2, 0);
        break;
      }
      case TK_UMINUS: {
        assert( pExpr->pLeft );
        if( pExpr->pLeft->op==TK_FLOAT || pExpr->pLeft->op==TK_INTEGER ){
          Token *p = &pExpr->pLeft->token;
          char *z = sqliteMalloc( p->n + 2 );
          sprintf(z, "-%.*s", p->n, p->z);
          if( pExpr->pLeft->op==TK_INTEGER && sqliteFitsIn32Bits(z) ){
            sqliteVdbeAddOp(v, OP_Integer, atoi(z), 0);
          }else{
            sqliteVdbeAddOp(v, OP_String, 0, 0);
          }
          sqliteVdbeChangeP3(v, -1, z, p->n+1);
          sqliteFree(z);
          break;
        }
        /* Fall through into TK_NOT */
      }
      case TK_BITNOT:
      case TK_NOT: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, op, 0, 0);
        break;
      }
      case TK_ISNULL:
      case TK_NOTNULL: {
        int dest;
        sqliteVdbeAddOp(v, OP_Integer, 1, 0);
        sqliteExprCode(pParse, pExpr->pLeft);
        dest = sqliteVdbeCurrentAddr(v) + 2;
        sqliteVdbeAddOp(v, op, 1, dest);
        sqliteVdbeAddOp(v, OP_AddImm, -1, 0);
        break;
      }
      case TK_AGG_FUNCTION: {
        sqliteVdbeAddOp(v, OP_AggGet, 0, pExpr->iAgg);
        break;
      }
      case TK_GLOB:
      case TK_LIKE:
      case TK_FUNCTION: {
        ExprList *pList = pExpr->pList;
        int nExpr = pList ? pList->nExpr : 0;
        FuncDef *pDef;
        int nId;
        const char *zId;
        getFunctionName(pExpr, &zId, &nId);
        pDef = sqliteFindFunction(pParse->db, zId, nId, nExpr, 0);
        assert( pDef!=0 );
        nExpr = sqliteExprCodeExprList(pParse, pList, pDef->includeTypes);
        sqliteVdbeOp3(v, OP_Function, nExpr, 0, (char*)pDef, P3_POINTER);
        break;
      }
      case TK_SELECT: {
        sqliteVdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
        break;
      }
      case TK_IN: {
        int addr;
        sqliteVdbeAddOp(v, OP_Integer, 1, 0);
        sqliteExprCode(pParse, pExpr->pLeft);
        addr = sqliteVdbeCurrentAddr(v);
        sqliteVdbeAddOp(v, OP_NotNull, -1, addr+4);
        sqliteVdbeAddOp(v, OP_Pop, 2, 0);
        sqliteVdbeAddOp(v, OP_String, 0, 0);
        sqliteVdbeAddOp(v, OP_Goto, 0, addr+6);
        if( pExpr->pSelect ){
          sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, addr+6);
        }else{
          sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, addr+6);
        }
        sqliteVdbeAddOp(v, OP_AddImm, -1, 0);
        break;
      }
      case TK_BETWEEN: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, OP_Dup, 0, 0);
        sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
        sqliteVdbeAddOp(v, OP_Ge, 0, 0);
        sqliteVdbeAddOp(v, OP_Pull, 1, 0);
        sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
        sqliteVdbeAddOp(v, OP_Le, 0, 0);
        sqliteVdbeAddOp(v, OP_And, 0, 0);
        break;
      }
      case TK_UPLUS:
      case TK_AS: {
        sqliteExprCode(pParse, pExpr->pLeft);
        break;
      }
      case TK_CASE: {
        int expr_end_label;
        int jumpInst;
        int addr;
        int nExpr;
        int i;
  
        assert(pExpr->pList);
        assert((pExpr->pList->nExpr % 2) == 0);
        assert(pExpr->pList->nExpr > 0);
        nExpr = pExpr->pList->nExpr;
        expr_end_label = sqliteVdbeMakeLabel(v);
        if( pExpr->pLeft ){
          sqliteExprCode(pParse, pExpr->pLeft);
        }
        for(i=0; i<nExpr; i=i+2){
          sqliteExprCode(pParse, pExpr->pList->a[i].pExpr);
          if( pExpr->pLeft ){
            sqliteVdbeAddOp(v, OP_Dup, 1, 1);
            jumpInst = sqliteVdbeAddOp(v, OP_Ne, 1, 0);
            sqliteVdbeAddOp(v, OP_Pop, 1, 0);
          }else{
            jumpInst = sqliteVdbeAddOp(v, OP_IfNot, 1, 0);
          }
          sqliteExprCode(pParse, pExpr->pList->a[i+1].pExpr);
          sqliteVdbeAddOp(v, OP_Goto, 0, expr_end_label);
          addr = sqliteVdbeCurrentAddr(v);
          sqliteVdbeChangeP2(v, jumpInst, addr);
        }
        if( pExpr->pLeft ){
          sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        }
        if( pExpr->pRight ){
          sqliteExprCode(pParse, pExpr->pRight);
        }else{
          sqliteVdbeAddOp(v, OP_String, 0, 0);
        }
        sqliteVdbeResolveLabel(v, expr_end_label);
        break;
      }
      case TK_RAISE: {
        if( !pParse->trigStack ){
          sqliteErrorMsg(pParse,
                         "RAISE() may only be used within a trigger-program");
          pParse->nErr++;
  	return;
        }
        if( pExpr->iColumn == OE_Rollback ||
  	  pExpr->iColumn == OE_Abort ||
  	  pExpr->iColumn == OE_Fail ){
  	  sqliteVdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
                             pExpr->token.z, pExpr->token.n);
  	  sqliteVdbeDequoteP3(v, -1);
        } else {
  	  assert( pExpr->iColumn == OE_Ignore );
  	  sqliteVdbeOp3(v, OP_Goto, 0, pParse->trigStack->ignoreJump,
                             "(IGNORE jump)", 0);
        }
      }
      break;
    }
  }
  
  /*
  ** Generate code that pushes the value of every element of the given
  ** expression list onto the stack.  If the includeTypes flag is true,
  ** then also push a string that is the datatype of each element onto
  ** the stack after the value.
  **
  ** Return the number of elements pushed onto the stack.
  */
  int sqliteExprCodeExprList(
    Parse *pParse,     /* Parsing context */
    ExprList *pList,   /* The expression list to be coded */
    int includeTypes   /* TRUE to put datatypes on the stack too */
  ){
    struct ExprList_item *pItem;
    int i, n;
    Vdbe *v;
    if( pList==0 ) return 0;
    v = sqliteGetVdbe(pParse);
    n = pList->nExpr;
    for(pItem=pList->a, i=0; i<n; i++, pItem++){
      sqliteExprCode(pParse, pItem->pExpr);
      if( includeTypes ){
        sqliteVdbeOp3(v, OP_String, 0, 0, 
           sqliteExprType(pItem->pExpr)==SQLITE_SO_NUM ? "numeric" : "text",
           P3_STATIC);
      }
    }
    return includeTypes ? n*2 : n;
  }
  
  /*
  ** Generate code for a boolean expression such that a jump is made
  ** to the label "dest" if the expression is true but execution
  ** continues straight thru if the expression is false.
  **
  ** If the expression evaluates to NULL (neither true nor false), then
  ** take the jump if the jumpIfNull flag is true.
  */
  void sqliteExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
    Vdbe *v = pParse->pVdbe;
    int op = 0;
    if( v==0 || pExpr==0 ) return;
    switch( pExpr->op ){
      case TK_LT:       op = OP_Lt;       break;
      case TK_LE:       op = OP_Le;       break;
      case TK_GT:       op = OP_Gt;       break;
      case TK_GE:       op = OP_Ge;       break;
      case TK_NE:       op = OP_Ne;       break;
      case TK_EQ:       op = OP_Eq;       break;
      case TK_ISNULL:   op = OP_IsNull;   break;
      case TK_NOTNULL:  op = OP_NotNull;  break;
      default:  break;
    }
    switch( pExpr->op ){
      case TK_AND: {
        int d2 = sqliteVdbeMakeLabel(v);
        sqliteExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
        sqliteExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
        sqliteVdbeResolveLabel(v, d2);
        break;
      }
      case TK_OR: {
        sqliteExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
        sqliteExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
        break;
      }
      case TK_NOT: {
        sqliteExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
        break;
      }
      case TK_LT:
      case TK_LE:
      case TK_GT:
      case TK_GE:
      case TK_NE:
      case TK_EQ: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteExprCode(pParse, pExpr->pRight);
        if( pParse->db->file_format>=4 && sqliteExprType(pExpr)==SQLITE_SO_TEXT ){
          op += 6;  /* Convert numeric opcodes to text opcodes */
        }
        sqliteVdbeAddOp(v, op, jumpIfNull, dest);
        break;
      }
      case TK_ISNULL:
      case TK_NOTNULL: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, op, 1, dest);
        break;
      }
      case TK_IN: {
        int addr;
        sqliteExprCode(pParse, pExpr->pLeft);
        addr = sqliteVdbeCurrentAddr(v);
        sqliteVdbeAddOp(v, OP_NotNull, -1, addr+3);
        sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        sqliteVdbeAddOp(v, OP_Goto, 0, jumpIfNull ? dest : addr+4);
        if( pExpr->pSelect ){
          sqliteVdbeAddOp(v, OP_Found, pExpr->iTable, dest);
        }else{
          sqliteVdbeAddOp(v, OP_SetFound, pExpr->iTable, dest);
        }
        break;
      }
      case TK_BETWEEN: {
        int addr;
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, OP_Dup, 0, 0);
        sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
        addr = sqliteVdbeAddOp(v, OP_Lt, !jumpIfNull, 0);
        sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
        sqliteVdbeAddOp(v, OP_Le, jumpIfNull, dest);
        sqliteVdbeAddOp(v, OP_Integer, 0, 0);
        sqliteVdbeChangeP2(v, addr, sqliteVdbeCurrentAddr(v));
        sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        break;
      }
      default: {
        sqliteExprCode(pParse, pExpr);
        sqliteVdbeAddOp(v, OP_If, jumpIfNull, dest);
        break;
      }
    }
  }
  
  /*
  ** Generate code for a boolean expression such that a jump is made
  ** to the label "dest" if the expression is false but execution
  ** continues straight thru if the expression is true.
  **
  ** If the expression evaluates to NULL (neither true nor false) then
  ** jump if jumpIfNull is true or fall through if jumpIfNull is false.
  */
  void sqliteExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
    Vdbe *v = pParse->pVdbe;
    int op = 0;
    if( v==0 || pExpr==0 ) return;
    switch( pExpr->op ){
      case TK_LT:       op = OP_Ge;       break;
      case TK_LE:       op = OP_Gt;       break;
      case TK_GT:       op = OP_Le;       break;
      case TK_GE:       op = OP_Lt;       break;
      case TK_NE:       op = OP_Eq;       break;
      case TK_EQ:       op = OP_Ne;       break;
      case TK_ISNULL:   op = OP_NotNull;  break;
      case TK_NOTNULL:  op = OP_IsNull;   break;
      default:  break;
    }
    switch( pExpr->op ){
      case TK_AND: {
        sqliteExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
        sqliteExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
        break;
      }
      case TK_OR: {
        int d2 = sqliteVdbeMakeLabel(v);
        sqliteExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
        sqliteExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
        sqliteVdbeResolveLabel(v, d2);
        break;
      }
      case TK_NOT: {
        sqliteExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
        break;
      }
      case TK_LT:
      case TK_LE:
      case TK_GT:
      case TK_GE:
      case TK_NE:
      case TK_EQ: {
        if( pParse->db->file_format>=4 && sqliteExprType(pExpr)==SQLITE_SO_TEXT ){
          /* Convert numeric comparison opcodes into text comparison opcodes.
          ** This step depends on the fact that the text comparision opcodes are
          ** always 6 greater than their corresponding numeric comparison
          ** opcodes.
          */
          assert( OP_Eq+6 == OP_StrEq );
          op += 6;
        }
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteExprCode(pParse, pExpr->pRight);
        sqliteVdbeAddOp(v, op, jumpIfNull, dest);
        break;
      }
      case TK_ISNULL:
      case TK_NOTNULL: {
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, op, 1, dest);
        break;
      }
      case TK_IN: {
        int addr;
        sqliteExprCode(pParse, pExpr->pLeft);
        addr = sqliteVdbeCurrentAddr(v);
        sqliteVdbeAddOp(v, OP_NotNull, -1, addr+3);
        sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        sqliteVdbeAddOp(v, OP_Goto, 0, jumpIfNull ? dest : addr+4);
        if( pExpr->pSelect ){
          sqliteVdbeAddOp(v, OP_NotFound, pExpr->iTable, dest);
        }else{
          sqliteVdbeAddOp(v, OP_SetNotFound, pExpr->iTable, dest);
        }
        break;
      }
      case TK_BETWEEN: {
        int addr;
        sqliteExprCode(pParse, pExpr->pLeft);
        sqliteVdbeAddOp(v, OP_Dup, 0, 0);
        sqliteExprCode(pParse, pExpr->pList->a[0].pExpr);
        addr = sqliteVdbeCurrentAddr(v);
        sqliteVdbeAddOp(v, OP_Ge, !jumpIfNull, addr+3);
        sqliteVdbeAddOp(v, OP_Pop, 1, 0);
        sqliteVdbeAddOp(v, OP_Goto, 0, dest);
        sqliteExprCode(pParse, pExpr->pList->a[1].pExpr);
        sqliteVdbeAddOp(v, OP_Gt, jumpIfNull, dest);
        break;
      }
      default: {
        sqliteExprCode(pParse, pExpr);
        sqliteVdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
        break;
      }
    }
  }
  
  /*
  ** Do a deep comparison of two expression trees.  Return TRUE (non-zero)
  ** if they are identical and return FALSE if they differ in any way.
  */
  int sqliteExprCompare(Expr *pA, Expr *pB){
    int i;
    if( pA==0 ){
      return pB==0;
    }else if( pB==0 ){
      return 0;
    }
    if( pA->op!=pB->op ) return 0;
    if( !sqliteExprCompare(pA->pLeft, pB->pLeft) ) return 0;
    if( !sqliteExprCompare(pA->pRight, pB->pRight) ) return 0;
    if( pA->pList ){
      if( pB->pList==0 ) return 0;
      if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
      for(i=0; i<pA->pList->nExpr; i++){
        if( !sqliteExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
          return 0;
        }
      }
    }else if( pB->pList ){
      return 0;
    }
    if( pA->pSelect || pB->pSelect ) return 0;
    if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
    if( pA->token.z ){
      if( pB->token.z==0 ) return 0;
      if( pB->token.n!=pA->token.n ) return 0;
      if( sqliteStrNICmp(pA->token.z, pB->token.z, pB->token.n)!=0 ) return 0;
    }
    return 1;
  }
  
  /*
  ** Add a new element to the pParse->aAgg[] array and return its index.
  */
  static int appendAggInfo(Parse *pParse){
    if( (pParse->nAgg & 0x7)==0 ){
      int amt = pParse->nAgg + 8;
      AggExpr *aAgg = sqliteRealloc(pParse->aAgg, amt*sizeof(pParse->aAgg[0]));
      if( aAgg==0 ){
        return -1;
      }
      pParse->aAgg = aAgg;
    }
    memset(&pParse->aAgg[pParse->nAgg], 0, sizeof(pParse->aAgg[0]));
    return pParse->nAgg++;
  }
  
  /*
  ** Analyze the given expression looking for aggregate functions and
  ** for variables that need to be added to the pParse->aAgg[] array.
  ** Make additional entries to the pParse->aAgg[] array as necessary.
  **
  ** This routine should only be called after the expression has been
  ** analyzed by sqliteExprResolveIds() and sqliteExprCheck().
  **
  ** If errors are seen, leave an error message in zErrMsg and return
  ** the number of errors.
  */
  int sqliteExprAnalyzeAggregates(Parse *pParse, Expr *pExpr){
    int i;
    AggExpr *aAgg;
    int nErr = 0;
  
    if( pExpr==0 ) return 0;
    switch( pExpr->op ){
      case TK_COLUMN: {
        aAgg = pParse->aAgg;
        for(i=0; i<pParse->nAgg; i++){
          if( aAgg[i].isAgg ) continue;
          if( aAgg[i].pExpr->iTable==pExpr->iTable
           && aAgg[i].pExpr->iColumn==pExpr->iColumn ){
            break;
          }
        }
        if( i>=pParse->nAgg ){
          i = appendAggInfo(pParse);
          if( i<0 ) return 1;
          pParse->aAgg[i].isAgg = 0;
          pParse->aAgg[i].pExpr = pExpr;
        }
        pExpr->iAgg = i;
        break;
      }
      case TK_AGG_FUNCTION: {
        aAgg = pParse->aAgg;
        for(i=0; i<pParse->nAgg; i++){
          if( !aAgg[i].isAgg ) continue;
          if( sqliteExprCompare(aAgg[i].pExpr, pExpr) ){
            break;
          }
        }
        if( i>=pParse->nAgg ){
          i = appendAggInfo(pParse);
          if( i<0 ) return 1;
          pParse->aAgg[i].isAgg = 1;
          pParse->aAgg[i].pExpr = pExpr;
          pParse->aAgg[i].pFunc = sqliteFindFunction(pParse->db,
               pExpr->token.z, pExpr->token.n,
               pExpr->pList ? pExpr->pList->nExpr : 0, 0);
        }
        pExpr->iAgg = i;
        break;
      }
      default: {
        if( pExpr->pLeft ){
          nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pLeft);
        }
        if( nErr==0 && pExpr->pRight ){
          nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pRight);
        }
        if( nErr==0 && pExpr->pList ){
          int n = pExpr->pList->nExpr;
          int i;
          for(i=0; nErr==0 && i<n; i++){
            nErr = sqliteExprAnalyzeAggregates(pParse, pExpr->pList->a[i].pExpr);
          }
        }
        break;
      }
    }
    return nErr;
  }
  
  /*
  ** Locate a user function given a name and a number of arguments.
  ** Return a pointer to the FuncDef structure that defines that
  ** function, or return NULL if the function does not exist.
  **
  ** If the createFlag argument is true, then a new (blank) FuncDef
  ** structure is created and liked into the "db" structure if a
  ** no matching function previously existed.  When createFlag is true
  ** and the nArg parameter is -1, then only a function that accepts
  ** any number of arguments will be returned.
  **
  ** If createFlag is false and nArg is -1, then the first valid
  ** function found is returned.  A function is valid if either xFunc
  ** or xStep is non-zero.
  */
  FuncDef *sqliteFindFunction(
    sqlite *db,        /* An open database */
    const char *zName, /* Name of the function.  Not null-terminated */
    int nName,         /* Number of characters in the name */
    int nArg,          /* Number of arguments.  -1 means any number */
    int createFlag     /* Create new entry if true and does not otherwise exist */
  ){
    FuncDef *pFirst, *p, *pMaybe;
    pFirst = p = (FuncDef*)sqliteHashFind(&db->aFunc, zName, nName);
    if( p && !createFlag && nArg<0 ){
      while( p && p->xFunc==0 && p->xStep==0 ){ p = p->pNext; }
      return p;
    }
    pMaybe = 0;
    while( p && p->nArg!=nArg ){
      if( p->nArg<0 && !createFlag && (p->xFunc || p->xStep) ) pMaybe = p;
      p = p->pNext;
    }
    if( p && !createFlag && p->xFunc==0 && p->xStep==0 ){
      return 0;
    }
    if( p==0 && pMaybe ){
      assert( createFlag==0 );
      return pMaybe;
    }
    if( p==0 && createFlag && (p = sqliteMalloc(sizeof(*p)))!=0 ){
      p->nArg = nArg;
      p->pNext = pFirst;
      p->dataType = pFirst ? pFirst->dataType : SQLITE_NUMERIC;
      sqliteHashInsert(&db->aFunc, zName, nName, (void*)p);
    }
    return p;
  }
  