engine/sqlite/src/select.cpp
changeset 71 fbd95db6a4e1
parent 69 4a65cc85c4f3
child 72 2e267e7da513
--- a/engine/sqlite/src/select.cpp	Wed Apr 28 13:20:05 2010 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,3667 +0,0 @@
-/*
-** 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 C code routines that are called by the parser
-** to handle SELECT statements in SQLite.
-**
-** $Id: select.cpp 1282 2008-11-13 09:31:33Z LarsPson $
-*/
-#include "sqliteInt.h"
-
-
-/*
-** Delete all the content of a Select structure but do not deallocate
-** the select structure itself.
-*/
-static void clearSelect(Select *p){
-  sqlite3ExprListDelete(p->pEList);
-  sqlite3SrcListDelete(p->pSrc);
-  sqlite3ExprDelete(p->pWhere);
-  sqlite3ExprListDelete(p->pGroupBy);
-  sqlite3ExprDelete(p->pHaving);
-  sqlite3ExprListDelete(p->pOrderBy);
-  sqlite3SelectDelete(p->pPrior);
-  sqlite3ExprDelete(p->pLimit);
-  sqlite3ExprDelete(p->pOffset);
-}
-
-
-/*
-** Allocate a new Select structure and return a pointer to that
-** structure.
-*/
-Select *sqlite3SelectNew(
-  Parse *pParse,        /* Parsing context */
-  ExprList *pEList,     /* which columns to include in the result */
-  SrcList *pSrc,        /* the FROM clause -- which tables to scan */
-  Expr *pWhere,         /* the WHERE clause */
-  ExprList *pGroupBy,   /* the GROUP BY clause */
-  Expr *pHaving,        /* the HAVING clause */
-  ExprList *pOrderBy,   /* the ORDER BY clause */
-  int isDistinct,       /* true if the DISTINCT keyword is present */
-  Expr *pLimit,         /* LIMIT value.  NULL means not used */
-  Expr *pOffset         /* OFFSET value.  NULL means no offset */
-){
-  Select *pNew;
-  Select standin;
-  sqlite3 *db = pParse->db;
-  pNew = (Select*)sqlite3DbMallocZero(db, sizeof(*pNew) );
-  assert( !pOffset || pLimit );   /* Can't have OFFSET without LIMIT. */
-  if( pNew==0 ){
-    pNew = &standin;
-    memset(pNew, 0, sizeof(*pNew));
-  }
-  if( pEList==0 ){
-    pEList = sqlite3ExprListAppend(pParse, 0, sqlite3Expr(db,TK_ALL,0,0,0), 0);
-  }
-  pNew->pEList = pEList;
-  pNew->pSrc = pSrc;
-  pNew->pWhere = pWhere;
-  pNew->pGroupBy = pGroupBy;
-  pNew->pHaving = pHaving;
-  pNew->pOrderBy = pOrderBy;
-  pNew->isDistinct = isDistinct;
-  pNew->op = TK_SELECT;
-  assert( pOffset==0 || pLimit!=0 );
-  pNew->pLimit = pLimit;
-  pNew->pOffset = pOffset;
-  pNew->iLimit = -1;
-  pNew->iOffset = -1;
-  pNew->addrOpenEphm[0] = -1;
-  pNew->addrOpenEphm[1] = -1;
-  pNew->addrOpenEphm[2] = -1;
-  if( pNew==&standin) {
-    clearSelect(pNew);
-    pNew = 0;
-  }
-  return pNew;
-}
-
-/*
-** Delete the given Select structure and all of its substructures.
-*/
-void sqlite3SelectDelete(Select *p){
-  if( p ){
-    clearSelect(p);
-    sqlite3_free(p);
-  }
-}
-
-/*
-** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
-** type of join.  Return an integer constant that expresses that type
-** in terms of the following bit values:
-**
-**     JT_INNER
-**     JT_CROSS
-**     JT_OUTER
-**     JT_NATURAL
-**     JT_LEFT
-**     JT_RIGHT
-**
-** A full outer join is the combination of JT_LEFT and JT_RIGHT.
-**
-** If an illegal or unsupported join type is seen, then still return
-** a join type, but put an error in the pParse structure.
-*/
-int sqlite3JoinType(Parse *pParse, Token *pA, Token *pB, Token *pC){
-  int jointype = 0;
-  Token *apAll[3];
-  Token *p;
-  static const struct {
-    const char zKeyword[8];
-    u8 nChar;
-    u8 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 },
-    { "cross",   5, JT_INNER|JT_CROSS },
-  };
-  int i, j;
-  apAll[0] = pA;
-  apAll[1] = pB;
-  apAll[2] = pC;
-  for(i=0; i<3 && apAll[i]; i++){
-    p = apAll[i];
-    for(j=0; j<sizeof(keywords)/sizeof(keywords[0]); j++){
-      if( p->n==keywords[j].nChar 
-          && sqlite3StrNICmp((char*)p->z, keywords[j].zKeyword, p->n)==0 ){
-        jointype |= keywords[j].code;
-        break;
-      }
-    }
-    if( j>=sizeof(keywords)/sizeof(keywords[0]) ){
-      jointype |= JT_ERROR;
-      break;
-    }
-  }
-  if(
-     (jointype & (JT_INNER|JT_OUTER))==(JT_INNER|JT_OUTER) ||
-     (jointype & JT_ERROR)!=0
-  ){
-    const char *zSp1 = " ";
-    const char *zSp2 = " ";
-    if( pB==0 ){ zSp1++; }
-    if( pC==0 ){ zSp2++; }
-    sqlite3ErrorMsg(pParse, "unknown or unsupported join type: "
-       "%T%s%T%s%T", pA, zSp1, pB, zSp2, pC);
-    jointype = JT_INNER;
-  }else if( jointype & JT_RIGHT ){
-    sqlite3ErrorMsg(pParse, 
-      "RIGHT and FULL OUTER JOINs are not currently supported");
-    jointype = JT_INNER;
-  }
-  return jointype;
-}
-
-/*
-** Return the index of a column in a table.  Return -1 if the column
-** is not contained in the table.
-*/
-static int columnIndex(Table *pTab, const char *zCol){
-  int i;
-  for(i=0; i<pTab->nCol; i++){
-    if( sqlite3StrICmp(pTab->aCol[i].zName, zCol)==0 ) return i;
-  }
-  return -1;
-}
-
-/*
-** Set the value of a token to a '\000'-terminated string.
-*/
-static void setToken(Token *p, const char *z){
-  p->z = (u8*)z;
-  p->n = z ? strlen(z) : 0;
-  p->dyn = 0;
-}
-
-/*
-** Set the token to the double-quoted and escaped version of the string pointed
-** to by z. For example;
-**
-**    {a"bc}  ->  {"a""bc"}
-*/
-static void setQuotedToken(Parse *pParse, Token *p, const char *z){
-  p->z = (u8 *)sqlite3MPrintf(0, "\"%w\"", z);
-  p->dyn = 1;
-  if( p->z ){
-    p->n = strlen((char *)p->z);
-  }else{
-    pParse->db->mallocFailed = 1;
-  }
-}
-
-/*
-** Create an expression node for an identifier with the name of zName
-*/
-Expr *sqlite3CreateIdExpr(Parse *pParse, const char *zName){
-  Token dummy;
-  setToken(&dummy, zName);
-  return sqlite3PExpr(pParse, TK_ID, 0, 0, &dummy);
-}
-
-
-/*
-** Add a term to the WHERE expression in *ppExpr that requires the
-** zCol column to be equal in the two tables pTab1 and pTab2.
-*/
-static void addWhereTerm(
-  Parse *pParse,           /* Parsing context */
-  const char *zCol,        /* Name of the column */
-  const Table *pTab1,      /* First table */
-  const char *zAlias1,     /* Alias for first table.  May be NULL */
-  const Table *pTab2,      /* Second table */
-  const char *zAlias2,     /* Alias for second table.  May be NULL */
-  int iRightJoinTable,     /* VDBE cursor for the right table */
-  Expr **ppExpr            /* Add the equality term to this expression */
-){
-  Expr *pE1a, *pE1b, *pE1c;
-  Expr *pE2a, *pE2b, *pE2c;
-  Expr *pE;
-
-  pE1a = sqlite3CreateIdExpr(pParse, zCol);
-  pE2a = sqlite3CreateIdExpr(pParse, zCol);
-  if( zAlias1==0 ){
-    zAlias1 = pTab1->zName;
-  }
-  pE1b = sqlite3CreateIdExpr(pParse, zAlias1);
-  if( zAlias2==0 ){
-    zAlias2 = pTab2->zName;
-  }
-  pE2b = sqlite3CreateIdExpr(pParse, zAlias2);
-  pE1c = sqlite3PExpr(pParse, TK_DOT, pE1b, pE1a, 0);
-  pE2c = sqlite3PExpr(pParse, TK_DOT, pE2b, pE2a, 0);
-  pE = sqlite3PExpr(pParse, TK_EQ, pE1c, pE2c, 0);
-  if( pE ){
-    ExprSetProperty(pE, EP_FromJoin);
-    pE->iRightJoinTable = iRightJoinTable;
-  }
-  *ppExpr = sqlite3ExprAnd(pParse->db,*ppExpr, pE);
-}
-
-/*
-** Set the EP_FromJoin property on all terms of the given expression.
-** And set the Expr.iRightJoinTable to iTable for every term in the
-** expression.
-**
-** The EP_FromJoin property is used on terms of an expression to tell
-** the LEFT OUTER JOIN processing logic that this term is part of the
-** join restriction specified in the ON or USING clause and not a part
-** of the more general WHERE clause.  These terms are moved over to the
-** WHERE clause during join processing but we need to remember that they
-** originated in the ON or USING clause.
-**
-** The Expr.iRightJoinTable tells the WHERE clause processing that the
-** expression depends on table iRightJoinTable even if that table is not
-** explicitly mentioned in the expression.  That information is needed
-** for cases like this:
-**
-**    SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.b AND t1.x=5
-**
-** The where clause needs to defer the handling of the t1.x=5
-** term until after the t2 loop of the join.  In that way, a
-** NULL t2 row will be inserted whenever t1.x!=5.  If we do not
-** defer the handling of t1.x=5, it will be processed immediately
-** after the t1 loop and rows with t1.x!=5 will never appear in
-** the output, which is incorrect.
-*/
-static void setJoinExpr(Expr *p, int iTable){
-  while( p ){
-    ExprSetProperty(p, EP_FromJoin);
-    p->iRightJoinTable = iTable;
-    setJoinExpr(p->pLeft, iTable);
-    p = p->pRight;
-  } 
-}
-
-/*
-** This routine processes the join information for a SELECT statement.
-** ON and USING clauses are converted into extra terms of the WHERE clause.
-** NATURAL joins also create extra WHERE clause terms.
-**
-** The terms of a FROM clause are contained in the Select.pSrc structure.
-** The left most table is the first entry in Select.pSrc.  The right-most
-** table is the last entry.  The join operator is held in the entry to
-** the left.  Thus entry 0 contains the join operator for the join between
-** entries 0 and 1.  Any ON or USING clauses associated with the join are
-** also attached to the left entry.
-**
-** This routine returns the number of errors encountered.
-*/
-static int sqliteProcessJoin(Parse *pParse, Select *p){
-  SrcList *pSrc;                  /* All tables in the FROM clause */
-  int i, j;                       /* Loop counters */
-  SrcList::SrcList_item *pLeft;     /* Left table being joined */
-  SrcList::SrcList_item *pRight;    /* Right table being joined */
-
-  pSrc = p->pSrc;
-  pLeft = &pSrc->a[0];
-  pRight = &pLeft[1];
-  for(i=0; i<pSrc->nSrc-1; i++, pRight++, pLeft++){
-    Table *pLeftTab = pLeft->pTab;
-    Table *pRightTab = pRight->pTab;
-
-    if( pLeftTab==0 || pRightTab==0 ) continue;
-
-    /* When the NATURAL keyword is present, add WHERE clause terms for
-    ** every column that the two tables have in common.
-    */
-    if( pRight->jointype & JT_NATURAL ){
-      if( pRight->pOn || pRight->pUsing ){
-        sqlite3ErrorMsg(pParse, "a NATURAL join may not have "
-           "an ON or USING clause", 0);
-        return 1;
-      }
-      for(j=0; j<pLeftTab->nCol; j++){
-        char *zName = pLeftTab->aCol[j].zName;
-        if( columnIndex(pRightTab, zName)>=0 ){
-          addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias, 
-                              pRightTab, pRight->zAlias,
-                              pRight->iCursor, &p->pWhere);
-          
-        }
-      }
-    }
-
-    /* Disallow both ON and USING clauses in the same join
-    */
-    if( pRight->pOn && pRight->pUsing ){
-      sqlite3ErrorMsg(pParse, "cannot have both ON and USING "
-        "clauses in the same join");
-      return 1;
-    }
-
-    /* Add the ON clause to the end of the WHERE clause, connected by
-    ** an AND operator.
-    */
-    if( pRight->pOn ){
-      setJoinExpr(pRight->pOn, pRight->iCursor);
-      p->pWhere = sqlite3ExprAnd(pParse->db, p->pWhere, pRight->pOn);
-      pRight->pOn = 0;
-    }
-
-    /* Create extra terms on the WHERE clause for each column named
-    ** in the USING clause.  Example: If the two tables to be joined are 
-    ** A and B and the USING clause names X, Y, and Z, then add this
-    ** to the WHERE clause:    A.X=B.X AND A.Y=B.Y AND A.Z=B.Z
-    ** Report an error if any column mentioned in the USING clause is
-    ** not contained in both tables to be joined.
-    */
-    if( pRight->pUsing ){
-      IdList *pList = pRight->pUsing;
-      for(j=0; j<pList->nId; j++){
-        char *zName = pList->a[j].zName;
-        if( columnIndex(pLeftTab, zName)<0 || columnIndex(pRightTab, zName)<0 ){
-          sqlite3ErrorMsg(pParse, "cannot join using column %s - column "
-            "not present in both tables", zName);
-          return 1;
-        }
-        addWhereTerm(pParse, zName, pLeftTab, pLeft->zAlias, 
-                            pRightTab, pRight->zAlias,
-                            pRight->iCursor, &p->pWhere);
-      }
-    }
-  }
-  return 0;
-}
-
-/*
-** Insert code into "v" that will push the record on the top of the
-** stack into the sorter.
-*/
-static void pushOntoSorter(
-  Parse *pParse,         /* Parser context */
-  ExprList *pOrderBy,    /* The ORDER BY clause */
-  Select *pSelect        /* The whole SELECT statement */
-){
-  Vdbe *v = pParse->pVdbe;
-  sqlite3ExprCodeExprList(pParse, pOrderBy);
-  sqlite3VdbeAddOp(v, OP_Sequence, pOrderBy->iECursor, 0);
-  sqlite3VdbeAddOp(v, OP_Pull, pOrderBy->nExpr + 1, 0);
-  sqlite3VdbeAddOp(v, OP_MakeRecord, pOrderBy->nExpr + 2, 0);
-  sqlite3VdbeAddOp(v, OP_IdxInsert, pOrderBy->iECursor, 0);
-  if( pSelect->iLimit>=0 ){
-    int addr1, addr2;
-    addr1 = sqlite3VdbeAddOp(v, OP_IfMemZero, pSelect->iLimit+1, 0);
-    sqlite3VdbeAddOp(v, OP_MemIncr, -1, pSelect->iLimit+1);
-    addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
-    sqlite3VdbeJumpHere(v, addr1);
-    sqlite3VdbeAddOp(v, OP_Last, pOrderBy->iECursor, 0);
-    sqlite3VdbeAddOp(v, OP_Delete, pOrderBy->iECursor, 0);
-    sqlite3VdbeJumpHere(v, addr2);
-    pSelect->iLimit = -1;
-  }
-}
-
-/*
-** Add code to implement the OFFSET
-*/
-static void codeOffset(
-  Vdbe *v,          /* Generate code into this VM */
-  Select *p,        /* The SELECT statement being coded */
-  int iContinue,    /* Jump here to skip the current record */
-  int nPop          /* Number of times to pop stack when jumping */
-){
-  if( p->iOffset>=0 && iContinue!=0 ){
-    int addr;
-    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iOffset);
-    addr = sqlite3VdbeAddOp(v, OP_IfMemNeg, p->iOffset, 0);
-    if( nPop>0 ){
-      sqlite3VdbeAddOp(v, OP_Pop, nPop, 0);
-    }
-    sqlite3VdbeAddOp(v, OP_Goto, 0, iContinue);
-    VdbeComment((v, "# skip OFFSET records"));
-    sqlite3VdbeJumpHere(v, addr);
-  }
-}
-
-/*
-** Add code that will check to make sure the top N elements of the
-** stack are distinct.  iTab is a sorting index that holds previously
-** seen combinations of the N values.  A new entry is made in iTab
-** if the current N values are new.
-**
-** A jump to addrRepeat is made and the N+1 values are popped from the
-** stack if the top N elements are not distinct.
-*/
-static void codeDistinct(
-  Vdbe *v,           /* Generate code into this VM */
-  int iTab,          /* A sorting index used to test for distinctness */
-  int addrRepeat,    /* Jump to here if not distinct */
-  int N              /* The top N elements of the stack must be distinct */
-){
-  sqlite3VdbeAddOp(v, OP_MakeRecord, -N, 0);
-  sqlite3VdbeAddOp(v, OP_Distinct, iTab, sqlite3VdbeCurrentAddr(v)+3);
-  sqlite3VdbeAddOp(v, OP_Pop, N+1, 0);
-  sqlite3VdbeAddOp(v, OP_Goto, 0, addrRepeat);
-  VdbeComment((v, "# skip indistinct records"));
-  sqlite3VdbeAddOp(v, OP_IdxInsert, iTab, 0);
-}
-
-/*
-** Generate an error message when a SELECT is used within a subexpression
-** (example:  "a IN (SELECT * FROM table)") but it has more than 1 result
-** column.  We do this in a subroutine because the error occurs in multiple
-** places.
-*/
-static int checkForMultiColumnSelectError(Parse *pParse, int eDest, int nExpr){
-  if( nExpr>1 && (eDest==SRT_Mem || eDest==SRT_Set) ){
-    sqlite3ErrorMsg(pParse, "only a single result allowed for "
-       "a SELECT that is part of an expression");
-    return 1;
-  }else{
-    return 0;
-  }
-}
-
-/*
-** This routine generates the code for the inside of the inner loop
-** of a SELECT.
-**
-** If srcTab and nColumn are both zero, then the pEList expressions
-** are evaluated in order to get the data for this row.  If nColumn>0
-** then data is pulled from srcTab and pEList is used only to get the
-** datatypes for each column.
-*/
-static int selectInnerLoop(
-  Parse *pParse,          /* The parser context */
-  Select *p,              /* The complete select statement being coded */
-  ExprList *pEList,       /* List of values being extracted */
-  int srcTab,             /* Pull data from this table */
-  int nColumn,            /* Number of columns in the source table */
-  ExprList *pOrderBy,     /* If not NULL, sort results using this key */
-  int distinct,           /* If >=0, make sure results are distinct */
-  int eDest,              /* How to dispose of the results */
-  int iParm,              /* An argument to the disposal method */
-  int iContinue,          /* Jump here to continue with next row */
-  int iBreak,             /* Jump here to break out of the inner loop */
-  char *aff               /* affinity string if eDest is SRT_Union */
-){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  int hasDistinct;        /* True if the DISTINCT keyword is present */
-
-  if( v==0 ) return 0;
-  assert( pEList!=0 );
-
-  /* If there was a LIMIT clause on the SELECT statement, then do the check
-  ** to see if this row should be output.
-  */
-  hasDistinct = distinct>=0 && pEList->nExpr>0;
-  if( pOrderBy==0 && !hasDistinct ){
-    codeOffset(v, p, iContinue, 0);
-  }
-
-  /* Pull the requested columns.
-  */
-  if( nColumn>0 ){
-    for(i=0; i<nColumn; i++){
-      sqlite3VdbeAddOp(v, OP_Column, srcTab, i);
-    }
-  }else{
-    nColumn = pEList->nExpr;
-    sqlite3ExprCodeExprList(pParse, pEList);
-  }
-
-  /* If the DISTINCT keyword was present on the SELECT statement
-  ** and this row has been seen before, then do not make this row
-  ** part of the result.
-  */
-  if( hasDistinct ){
-    assert( pEList!=0 );
-    assert( pEList->nExpr==nColumn );
-    codeDistinct(v, distinct, iContinue, nColumn);
-    if( pOrderBy==0 ){
-      codeOffset(v, p, iContinue, nColumn);
-    }
-  }
-
-  if( checkForMultiColumnSelectError(pParse, eDest, pEList->nExpr) ){
-    return 0;
-  }
-
-  switch( eDest ){
-    /* In this mode, write each query result to the key of the temporary
-    ** table iParm.
-    */
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-    case SRT_Union: {
-      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
-      if( aff ){
-        sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
-      }
-      sqlite3VdbeAddOp(v, OP_IdxInsert, iParm, 0);
-      break;
-    }
-
-    /* Construct a record from the query result, but instead of
-    ** saving that record, use it as a key to delete elements from
-    ** the temporary table iParm.
-    */
-    case SRT_Except: {
-      int addr;
-      addr = sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
-      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
-      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
-      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
-      break;
-    }
-#endif
-
-    /* Store the result as data using a unique key.
-    */
-    case SRT_Table:
-    case SRT_EphemTab: {
-      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
-      if( pOrderBy ){
-        pushOntoSorter(pParse, pOrderBy, p);
-      }else{
-        sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
-        sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
-        sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
-      }
-      break;
-    }
-
-#ifndef SQLITE_OMIT_SUBQUERY
-    /* If we are creating a set for an "expr IN (SELECT ...)" construct,
-    ** then there should be a single item on the stack.  Write this
-    ** item into the set table with bogus data.
-    */
-    case SRT_Set: {
-      int addr1 = sqlite3VdbeCurrentAddr(v);
-      int addr2;
-
-      assert( nColumn==1 );
-      sqlite3VdbeAddOp(v, OP_NotNull, -1, addr1+3);
-      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
-      addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
-      p->affinity = sqlite3CompareAffinity(pEList->a[0].pExpr,(iParm>>16)&0xff);
-      if( pOrderBy ){
-        /* At first glance you would think we could optimize out the
-        ** ORDER BY in this case since the order of entries in the set
-        ** does not matter.  But there might be a LIMIT clause, in which
-        ** case the order does matter */
-        pushOntoSorter(pParse, pOrderBy, p);
-      }else{
-        sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
-        sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
-      }
-      sqlite3VdbeJumpHere(v, addr2);
-      break;
-    }
-
-    /* If any row exist in the result set, record that fact and abort.
-    */
-    case SRT_Exists: {
-      sqlite3VdbeAddOp(v, OP_MemInt, 1, iParm);
-      sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-
-    /* If this is a scalar select that is part of an expression, then
-    ** store the results in the appropriate memory cell and break out
-    ** of the scan loop.
-    */
-    case SRT_Mem: {
-      assert( nColumn==1 );
-      if( pOrderBy ){
-        pushOntoSorter(pParse, pOrderBy, p);
-      }else{
-        sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
-        /* The LIMIT clause will jump out of the loop for us */
-      }
-      break;
-    }
-#endif /* #ifndef SQLITE_OMIT_SUBQUERY */
-
-    /* Send the data to the callback function or to a subroutine.  In the
-    ** case of a subroutine, the subroutine itself is responsible for
-    ** popping the data from the stack.
-    */
-    case SRT_Subroutine:
-    case SRT_Callback: {
-      if( pOrderBy ){
-        sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
-        pushOntoSorter(pParse, pOrderBy, p);
-      }else if( eDest==SRT_Subroutine ){
-        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
-      }else{
-        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
-      }
-      break;
-    }
-
-#if !defined(SQLITE_OMIT_TRIGGER)
-    /* Discard the results.  This is used for SELECT statements inside
-    ** the body of a TRIGGER.  The purpose of such selects is to call
-    ** user-defined functions that have side effects.  We do not care
-    ** about the actual results of the select.
-    */
-    default: {
-      assert( eDest==SRT_Discard );
-      sqlite3VdbeAddOp(v, OP_Pop, nColumn, 0);
-      break;
-    }
-#endif
-  }
-
-  /* Jump to the end of the loop if the LIMIT is reached.
-  */
-  if( p->iLimit>=0 && pOrderBy==0 ){
-    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
-    sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, iBreak);
-  }
-  return 0;
-}
-
-/*
-** Given an expression list, generate a KeyInfo structure that records
-** the collating sequence for each expression in that expression list.
-**
-** If the ExprList is an ORDER BY or GROUP BY clause then the resulting
-** KeyInfo structure is appropriate for initializing a virtual index to
-** implement that clause.  If the ExprList is the result set of a SELECT
-** then the KeyInfo structure is appropriate for initializing a virtual
-** index to implement a DISTINCT test.
-**
-** Space to hold the KeyInfo structure is obtain from malloc.  The calling
-** function is responsible for seeing that this structure is eventually
-** freed.  Add the KeyInfo structure to the P3 field of an opcode using
-** P3_KEYINFO_HANDOFF is the usual way of dealing with this.
-*/
-static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
-  sqlite3 *db = pParse->db;
-  int nExpr;
-  KeyInfo *pInfo;
-  ExprList::ExprList_item *pItem;
-  int i;
-
-  nExpr = pList->nExpr;
-  pInfo = (KeyInfo*)sqlite3DbMallocZero(db, sizeof(*pInfo) + nExpr*(sizeof(CollSeq*)+1) );
-  if( pInfo ){
-    pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr];
-    pInfo->nField = nExpr;
-    pInfo->enc = ENC(db);
-    for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){
-      CollSeq *pColl;
-      pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      if( !pColl ){
-        pColl = db->pDfltColl;
-      }
-      pInfo->aColl[i] = pColl;
-      pInfo->aSortOrder[i] = pItem->sortOrder;
-    }
-  }
-  return pInfo;
-}
-
-
-/*
-** If the inner loop was generated using a non-null pOrderBy argument,
-** then the results were placed in a sorter.  After the loop is terminated
-** we need to run the sorter and output the results.  The following
-** routine generates the code needed to do that.
-*/
-static void generateSortTail(
-  Parse *pParse,   /* Parsing context */
-  Select *p,       /* The SELECT statement */
-  Vdbe *v,         /* Generate code into this VDBE */
-  int nColumn,     /* Number of columns of data */
-  int eDest,       /* Write the sorted results here */
-  int iParm        /* Optional parameter associated with eDest */
-){
-  int brk = sqlite3VdbeMakeLabel(v);
-  int cont = sqlite3VdbeMakeLabel(v);
-  int addr;
-  int iTab;
-  int pseudoTab = 0;
-  ExprList *pOrderBy = p->pOrderBy;
-
-  iTab = pOrderBy->iECursor;
-  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
-    pseudoTab = pParse->nTab++;
-    sqlite3VdbeAddOp(v, OP_OpenPseudo, pseudoTab, 0);
-    sqlite3VdbeAddOp(v, OP_SetNumColumns, pseudoTab, nColumn);
-  }
-  addr = 1 + sqlite3VdbeAddOp(v, OP_Sort, iTab, brk);
-  codeOffset(v, p, cont, 0);
-  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
-    sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
-  }
-  sqlite3VdbeAddOp(v, OP_Column, iTab, pOrderBy->nExpr + 1);
-  switch( eDest ){
-    case SRT_Table:
-    case SRT_EphemTab: {
-      sqlite3VdbeAddOp(v, OP_NewRowid, iParm, 0);
-      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
-      sqlite3VdbeAddOp(v, OP_Insert, iParm, OPFLAG_APPEND);
-      break;
-    }
-#ifndef SQLITE_OMIT_SUBQUERY
-    case SRT_Set: {
-      assert( nColumn==1 );
-      sqlite3VdbeAddOp(v, OP_NotNull, -1, sqlite3VdbeCurrentAddr(v)+3);
-      sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
-      sqlite3VdbeAddOp(v, OP_Goto, 0, sqlite3VdbeCurrentAddr(v)+3);
-      sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &p->affinity, 1);
-      sqlite3VdbeAddOp(v, OP_IdxInsert, (iParm&0x0000FFFF), 0);
-      break;
-    }
-    case SRT_Mem: {
-      assert( nColumn==1 );
-      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
-      /* The LIMIT clause will terminate the loop for us */
-      break;
-    }
-#endif
-    case SRT_Callback:
-    case SRT_Subroutine: {
-      int i;
-      sqlite3VdbeAddOp(v, OP_Insert, pseudoTab, 0);
-      for(i=0; i<nColumn; i++){
-        sqlite3VdbeAddOp(v, OP_Column, pseudoTab, i);
-      }
-      if( eDest==SRT_Callback ){
-        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
-      }else{
-        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
-      }
-      break;
-    }
-    default: {
-      /* Do nothing */
-      break;
-    }
-  }
-
-  /* Jump to the end of the loop when the LIMIT is reached
-  */
-  if( p->iLimit>=0 ){
-    sqlite3VdbeAddOp(v, OP_MemIncr, -1, p->iLimit);
-    sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, brk);
-  }
-
-  /* The bottom of the loop
-  */
-  sqlite3VdbeResolveLabel(v, cont);
-  sqlite3VdbeAddOp(v, OP_Next, iTab, addr);
-  sqlite3VdbeResolveLabel(v, brk);
-  if( eDest==SRT_Callback || eDest==SRT_Subroutine ){
-    sqlite3VdbeAddOp(v, OP_Close, pseudoTab, 0);
-  }
-
-}
-
-/*
-** Return a pointer to a string containing the 'declaration type' of the
-** expression pExpr. The string may be treated as static by the caller.
-**
-** The declaration type is the exact datatype definition extracted from the
-** original CREATE TABLE statement if the expression is a column. The
-** declaration type for a ROWID field is INTEGER. Exactly when an expression
-** is considered a column can be complex in the presence of subqueries. The
-** result-set expression in all of the following SELECT statements is 
-** considered a column by this function.
-**
-**   SELECT col FROM tbl;
-**   SELECT (SELECT col FROM tbl;
-**   SELECT (SELECT col FROM tbl);
-**   SELECT abc FROM (SELECT col AS abc FROM tbl);
-** 
-** The declaration type for any expression other than a column is NULL.
-*/
-static const char *columnType(
-  NameContext *pNC, 
-  Expr *pExpr,
-  const char **pzOriginDb,
-  const char **pzOriginTab,
-  const char **pzOriginCol
-){
-  char const *zType = 0;
-  char const *zOriginDb = 0;
-  char const *zOriginTab = 0;
-  char const *zOriginCol = 0;
-  int j;
-  if( pExpr==0 || pNC->pSrcList==0 ) return 0;
-
-  switch( pExpr->op ){
-    case TK_AGG_COLUMN:
-    case TK_COLUMN: {
-      /* The expression is a column. Locate the table the column is being
-      ** extracted from in NameContext.pSrcList. This table may be real
-      ** database table or a subquery.
-      */
-      Table *pTab = 0;            /* Table structure column is extracted from */
-      Select *pS = 0;             /* Select the column is extracted from */
-      int iCol = pExpr->iColumn;  /* Index of column in pTab */
-      while( pNC && !pTab ){
-        SrcList *pTabList = pNC->pSrcList;
-        for(j=0;j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->iTable;j++);
-        if( j<pTabList->nSrc ){
-          pTab = pTabList->a[j].pTab;
-          pS = pTabList->a[j].pSelect;
-        }else{
-          pNC = pNC->pNext;
-        }
-      }
-
-      if( pTab==0 ){
-        /* FIX ME:
-        ** This can occurs if you have something like "SELECT new.x;" inside
-        ** a trigger.  In other words, if you reference the special "new"
-        ** table in the result set of a select.  We do not have a good way
-        ** to find the actual table type, so call it "TEXT".  This is really
-        ** something of a bug, but I do not know how to fix it.
-        **
-        ** This code does not produce the correct answer - it just prevents
-        ** a segfault.  See ticket #1229.
-        */
-        zType = "TEXT";
-        break;
-      }
-
-      assert( pTab );
-      if( pS ){
-        /* The "table" is actually a sub-select or a view in the FROM clause
-        ** of the SELECT statement. Return the declaration type and origin
-        ** data for the result-set column of the sub-select.
-        */
-        if( iCol>=0 && iCol<pS->pEList->nExpr ){
-          /* If iCol is less than zero, then the expression requests the
-          ** rowid of the sub-select or view. This expression is legal (see 
-          ** test case misc2.2.2) - it always evaluates to NULL.
-          */
-          NameContext sNC;
-          Expr *p = pS->pEList->a[iCol].pExpr;
-          sNC.pSrcList = pS->pSrc;
-          sNC.pNext = 0;
-          sNC.pParse = pNC->pParse;
-          zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
-        }
-      }else if( pTab->pSchema ){
-        /* A real table */
-        assert( !pS );
-        if( iCol<0 ) iCol = pTab->iPKey;
-        assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
-        if( iCol<0 ){
-          zType = "INTEGER";
-          zOriginCol = "rowid";
-        }else{
-          zType = pTab->aCol[iCol].zType;
-          zOriginCol = pTab->aCol[iCol].zName;
-        }
-        zOriginTab = pTab->zName;
-        if( pNC->pParse ){
-          int iDb = sqlite3SchemaToIndex(pNC->pParse->db, pTab->pSchema);
-          zOriginDb = pNC->pParse->db->aDb[iDb].zName;
-        }
-      }
-      break;
-    }
-#ifndef SQLITE_OMIT_SUBQUERY
-    case TK_SELECT: {
-      /* The expression is a sub-select. Return the declaration type and
-      ** origin info for the single column in the result set of the SELECT
-      ** statement.
-      */
-      NameContext sNC;
-      Select *pS = pExpr->pSelect;
-      Expr *p = pS->pEList->a[0].pExpr;
-      sNC.pSrcList = pS->pSrc;
-      sNC.pNext = pNC;
-      sNC.pParse = pNC->pParse;
-      zType = columnType(&sNC, p, &zOriginDb, &zOriginTab, &zOriginCol); 
-      break;
-    }
-#endif
-  }
-  
-  if( pzOriginDb ){
-    assert( pzOriginTab && pzOriginCol );
-    *pzOriginDb = zOriginDb;
-    *pzOriginTab = zOriginTab;
-    *pzOriginCol = zOriginCol;
-  }
-  return zType;
-}
-
-/*
-** Generate code that will tell the VDBE the declaration types of columns
-** in the result set.
-*/
-static void generateColumnTypes(
-  Parse *pParse,      /* Parser context */
-  SrcList *pTabList,  /* List of tables */
-  ExprList *pEList    /* Expressions defining the result set */
-){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  NameContext sNC;
-  sNC.pSrcList = pTabList;
-  sNC.pParse = pParse;
-  for(i=0; i<pEList->nExpr; i++){
-    Expr *p = pEList->a[i].pExpr;
-    const char *zOrigDb = 0;
-    const char *zOrigTab = 0;
-    const char *zOrigCol = 0;
-    const char *zType = columnType(&sNC, p, &zOrigDb, &zOrigTab, &zOrigCol);
-
-    /* The vdbe must make its own copy of the column-type and other 
-    ** column specific strings, in case the schema is reset before this
-    ** virtual machine is deleted.
-    */
-    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, P3_TRANSIENT);
-    sqlite3VdbeSetColName(v, i, COLNAME_DATABASE, zOrigDb, P3_TRANSIENT);
-    sqlite3VdbeSetColName(v, i, COLNAME_TABLE, zOrigTab, P3_TRANSIENT);
-    sqlite3VdbeSetColName(v, i, COLNAME_COLUMN, zOrigCol, P3_TRANSIENT);
-  }
-}
-
-/*
-** Generate code that will tell the VDBE the names of columns
-** in the result set.  This information is used to provide the
-** azCol[] values in the callback.
-*/
-static void generateColumnNames(
-  Parse *pParse,      /* Parser context */
-  SrcList *pTabList,  /* List of tables */
-  ExprList *pEList    /* Expressions defining the result set */
-){
-  Vdbe *v = pParse->pVdbe;
-  int i, j;
-  sqlite3 *db = pParse->db;
-  int fullNames, shortNames;
-
-#ifndef SQLITE_OMIT_EXPLAIN
-  /* If this is an EXPLAIN, skip this step */
-  if( pParse->explain ){
-    return;
-  }
-#endif
-
-  assert( v!=0 );
-  if( pParse->colNamesSet || v==0 || db->mallocFailed ) return;
-  pParse->colNamesSet = 1;
-  fullNames = (db->flags & SQLITE_FullColNames)!=0;
-  shortNames = (db->flags & SQLITE_ShortColNames)!=0;
-  sqlite3VdbeSetNumCols(v, pEList->nExpr);
-  for(i=0; i<pEList->nExpr; i++){
-    Expr *p;
-    p = pEList->a[i].pExpr;
-    if( p==0 ) continue;
-    if( pEList->a[i].zName ){
-      char *zName = pEList->a[i].zName;
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, strlen(zName));
-      continue;
-    }
-    if( p->op==TK_COLUMN && pTabList ){
-      Table *pTab;
-      char *zCol;
-      int iCol = p->iColumn;
-      for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=p->iTable; j++){}
-      assert( j<pTabList->nSrc );
-      pTab = pTabList->a[j].pTab;
-      if( iCol<0 ) iCol = pTab->iPKey;
-      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
-      if( iCol<0 ){
-        zCol = "rowid";
-      }else{
-        zCol = pTab->aCol[iCol].zName;
-      }
-      if( !shortNames && !fullNames && p->span.z && p->span.z[0] ){
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
-      }else if( fullNames || (!shortNames && pTabList->nSrc>1) ){
-        char *zName = 0;
-        char *zTab;
- 
-        zTab = pTabList->a[j].zAlias;
-        if( fullNames || zTab==0 ) zTab = pTab->zName;
-        sqlite3SetString(&zName, zTab, ".", zCol, (char*)0);
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, P3_DYNAMIC);
-      }else{
-        sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, strlen(zCol));
-      }
-    }else if( p->span.z && p->span.z[0] ){
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, (char*)p->span.z, p->span.n);
-      /* sqlite3VdbeCompressSpace(v, addr); */
-    }else{
-      char zName[30];
-      assert( p->op!=TK_COLUMN || pTabList==0 );
-      sqlite3_snprintf(sizeof(zName), zName, "column%d", i+1);
-      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, 0);
-    }
-  }
-  generateColumnTypes(pParse, pTabList, pEList);
-}
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-/*
-** Name of the connection operator, used for error messages.
-*/
-static const char *selectOpName(int id){
-  char *z;
-  switch( id ){
-    case TK_ALL:       z = "UNION ALL";   break;
-    case TK_INTERSECT: z = "INTERSECT";   break;
-    case TK_EXCEPT:    z = "EXCEPT";      break;
-    default:           z = "UNION";       break;
-  }
-  return z;
-}
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
-
-/*
-** Forward declaration
-*/
-static int prepSelectStmt(Parse*, Select*);
-
-/*
-** 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, *pCol;
-  sqlite3 *db = pParse->db;
-
-  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
-  if( prepSelectStmt(pParse, pSelect) ){
-    return 0;
-  }
-  if( sqlite3SelectResolve(pParse, pSelect, 0) ){
-    return 0;
-  }
-  pTab = (Table*)sqlite3DbMallocZero(db, sizeof(Table) );
-  if( pTab==0 ){
-    return 0;
-  }
-  pTab->nRef = 1;
-  pTab->zName = zTabName ? sqlite3DbStrDup(db, zTabName) : 0;
-  pEList = pSelect->pEList;
-  pTab->nCol = pEList->nExpr;
-  assert( pTab->nCol>0 );
-  pTab->aCol = aCol = (Column*)sqlite3DbMallocZero(db, sizeof(pTab->aCol[0])*pTab->nCol);
-  for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
-    Expr *p, *pR;
-    char *zType;
-    char *zName;
-    int nName;
-    CollSeq *pColl;
-    int cnt;
-    NameContext sNC;
-    
-    /* Get an appropriate name for the column
-    */
-    p = pEList->a[i].pExpr;
-    assert( p->pRight==0 || p->pRight->token.z==0 || p->pRight->token.z[0]!=0 );
-    if( (zName = pEList->a[i].zName)!=0 ){
-      /* If the column contains an "AS <name>" phrase, use <name> as the name */
-      zName = sqlite3DbStrDup(db, zName);
-    }else if( p->op==TK_DOT 
-              && (pR=p->pRight)!=0 && pR->token.z && pR->token.z[0] ){
-      /* For columns of the from A.B use B as the name */
-      zName = sqlite3MPrintf(db, "%T", &pR->token);
-    }else if( p->span.z && p->span.z[0] ){
-      /* Use the original text of the column expression as its name */
-      zName = sqlite3MPrintf(db, "%T", &p->span);
-    }else{
-      /* If all else fails, make up a name */
-      zName = sqlite3MPrintf(db, "column%d", i+1);
-    }
-    if( !zName || db->mallocFailed ){
-      db->mallocFailed = 1;
-      sqlite3_free(zName);
-      sqlite3DeleteTable(pTab);
-      return 0;
-    }
-    sqlite3Dequote(zName);
-
-    /* Make sure the column name is unique.  If the name is not unique,
-    ** append a integer to the name so that it becomes unique.
-    */
-    nName = strlen(zName);
-    for(j=cnt=0; j<i; j++){
-      if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
-        zName[nName] = 0;
-        zName = sqlite3MPrintf(db, "%z:%d", zName, ++cnt);
-        j = -1;
-        if( zName==0 ) break;
-      }
-    }
-    pCol->zName = zName;
-
-    /* Get the typename, type affinity, and collating sequence for the
-    ** column.
-    */
-    memset(&sNC, 0, sizeof(sNC));
-    sNC.pSrcList = pSelect->pSrc;
-    zType = sqlite3DbStrDup(db, columnType(&sNC, p, 0, 0, 0));
-    pCol->zType = zType;
-    pCol->affinity = sqlite3ExprAffinity(p);
-    pColl = sqlite3ExprCollSeq(pParse, p);
-    if( pColl ){
-      pCol->zColl = sqlite3DbStrDup(db, pColl->zName);
-    }
-  }
-  pTab->iPKey = -1;
-  return pTab;
-}
-
-/*
-** Prepare a SELECT statement for processing by doing the following
-** things:
-**
-**    (1)  Make sure VDBE cursor numbers have been assigned to every
-**         element of the FROM clause.
-**
-**    (2)  Fill in the pTabList->a[].pTab fields in the SrcList that 
-**         defines FROM clause.  When views appear in the FROM clause,
-**         fill pTabList->a[].pSelect with a copy of the SELECT statement
-**         that implements the view.  A copy is made of the view's SELECT
-**         statement so that we can freely modify or delete that statement
-**         without worrying about messing up the presistent representation
-**         of the view.
-**
-**    (3)  Add terms to the WHERE clause to accomodate the NATURAL keyword
-**         on joins and the ON and USING clause of joins.
-**
-**    (4)  Scan the list of columns in the result set (pEList) looking
-**         for instances of the "*" operator or the TABLE.* operator.
-**         If found, expand each "*" to be every column in every table
-**         and TABLE.* to be every column in TABLE.
-**
-** Return 0 on success.  If there are problems, leave an error message
-** in pParse and return non-zero.
-*/
-static int prepSelectStmt(Parse *pParse, Select *p){
-  int i, j, k, rc;
-  SrcList *pTabList;
-  ExprList *pEList;
-  SrcList::SrcList_item *pFrom;
-  sqlite3 *db = pParse->db;
-
-  if( p==0 || p->pSrc==0 || db->mallocFailed ){
-    return 1;
-  }
-  pTabList = p->pSrc;
-  pEList = p->pEList;
-
-  /* Make sure cursor numbers have been assigned to all entries in
-  ** the FROM clause of the SELECT statement.
-  */
-  sqlite3SrcListAssignCursors(pParse, p->pSrc);
-
-  /* Look up every table named in the FROM clause of the select.  If
-  ** an entry of the FROM clause is a subquery instead of a table or view,
-  ** then create a transient table structure to describe the subquery.
-  */
-     Table *pTab;
- for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-    if( pFrom->pTab!=0 ){
-      /* This statement has already been prepared.  There is no need
-      ** to go further. */
-      assert( i==0 );
-      return 0;
-    }
-    if( pFrom->zName==0 ){
-#ifndef SQLITE_OMIT_SUBQUERY
-      /* A sub-query in the FROM clause of a SELECT */
-      assert( pFrom->pSelect!=0 );
-      if( pFrom->zAlias==0 ){
-        pFrom->zAlias =
-          sqlite3MPrintf(db, "sqlite_subquery_%p_", (void*)pFrom->pSelect);
-      }
-      assert( pFrom->pTab==0 );
-      pFrom->pTab = pTab = 
-        sqlite3ResultSetOfSelect(pParse, pFrom->zAlias, pFrom->pSelect);
-      if( pTab==0 ){
-        return 1;
-      }
-      /* The isEphem 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->isEphem = 1;
-#endif
-    }else{
-      /* An ordinary table or view name in the FROM clause */
-      assert( pFrom->pTab==0 );
-      pFrom->pTab = pTab = 
-        sqlite3LocateTable(pParse,pFrom->zName,pFrom->zDatabase);
-      if( pTab==0 ){
-        return 1;
-      }
-      pTab->nRef++;
-#if !defined(SQLITE_OMIT_VIEW) || !defined (SQLITE_OMIT_VIRTUALTABLE)
-      if( pTab->pSelect || IsVirtual(pTab) ){
-        /* We reach here if the named table is a really a view */
-        if( sqlite3ViewGetColumnNames(pParse, pTab) ){
-          return 1;
-        }
-        /* If pFrom->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( pFrom->pSelect==0 ){
-          pFrom->pSelect = sqlite3SelectDup(db, pTab->pSelect);
-        }
-      }
-#endif
-    }
-  }
-
-  /* Process NATURAL keywords, and ON and USING clauses of joins.
-  */
-  if( sqliteProcessJoin(pParse, p) ) return 1;
-
-  /* For every "*" that occurs in the column list, insert the names of
-  ** all columns in all tables.  And for every TABLE.* insert the names
-  ** of all columns in TABLE.  The parser inserted a special expression
-  ** with the TK_ALL operator for each "*" that it found in the column list.
-  ** The following code just has to locate the TK_ALL expressions and expand
-  ** each one to the list of all columns in all tables.
-  **
-  ** The first loop just checks to see if there are any "*" operators
-  ** that need expanding.
-  */
-  for(k=0; k<pEList->nExpr; k++){
-    Expr *pE = pEList->a[k].pExpr;
-    if( pE->op==TK_ALL ) break;
-    if( pE->op==TK_DOT && pE->pRight && pE->pRight->op==TK_ALL
-         && pE->pLeft && pE->pLeft->op==TK_ID ) break;
-  }
-  rc = 0;
-  if( k<pEList->nExpr ){
-    /*
-    ** If we get here it means the result set contains one or more "*"
-    ** operators that need to be expanded.  Loop through each expression
-    ** in the result set and expand them one by one.
-    */
-	  ExprList::ExprList_item *a = pEList->a;
-    ExprList *pNew = 0;
-    int flags = pParse->db->flags;
-    int longNames = (flags & SQLITE_FullColNames)!=0 &&
-                      (flags & SQLITE_ShortColNames)==0;
-
-    for(k=0; k<pEList->nExpr; k++){
-      Expr *pE = a[k].pExpr;
-      if( pE->op!=TK_ALL &&
-           (pE->op!=TK_DOT || pE->pRight==0 || pE->pRight->op!=TK_ALL) ){
-        /* This particular expression does not need to be expanded.
-        */
-        pNew = sqlite3ExprListAppend(pParse, pNew, a[k].pExpr, 0);
-        if( pNew ){
-          pNew->a[pNew->nExpr-1].zName = a[k].zName;
-        }else{
-          rc = 1;
-        }
-        a[k].pExpr = 0;
-        a[k].zName = 0;
-      }else{
-        /* This expression is a "*" or a "TABLE.*" and needs to be
-        ** expanded. */
-        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(db, &pE->pLeft->token);
-        }else{
-          zTName = 0;
-        }
-        for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
-          Table *pTab = pFrom->pTab;
-          char *zTabName = pFrom->zAlias;
-          if( zTabName==0 || zTabName[0]==0 ){ 
-            zTabName = pTab->zName;
-          }
-          if( zTName && (zTabName==0 || zTabName[0]==0 || 
-                 sqlite3StrICmp(zTName, zTabName)!=0) ){
-            continue;
-          }
-          tableSeen = 1;
-          for(j=0; j<pTab->nCol; j++){
-            Expr *pExpr, *pRight;
-            char *zName = pTab->aCol[j].zName;
-
-            /* If a column is marked as 'hidden' (currently only possible
-            ** for virtual tables), do not include it in the expanded
-            ** result-set list.
-            */
-            if( IsHiddenColumn(&pTab->aCol[j]) ){
-              assert(IsVirtual(pTab));
-              continue;
-            }
-
-            if( i>0 ){
-				SrcList::SrcList_item *pLeft = &pTabList->a[i-1];
-              if( (pLeft[1].jointype & JT_NATURAL)!=0 &&
-                        columnIndex(pLeft->pTab, zName)>=0 ){
-                /* In a NATURAL join, omit the join columns from the 
-                ** table on the right */
-                continue;
-              }
-              if( sqlite3IdListIndex(pLeft[1].pUsing, zName)>=0 ){
-                /* In a join with a USING clause, omit columns in the
-                ** using clause from the table on the right. */
-                continue;
-              }
-            }
-            pRight = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
-            if( pRight==0 ) break;
-            setQuotedToken(pParse, &pRight->token, zName);
-            if( zTabName && (longNames || pTabList->nSrc>1) ){
-              Expr *pLeft = sqlite3PExpr(pParse, TK_ID, 0, 0, 0);
-              pExpr = sqlite3PExpr(pParse, TK_DOT, pLeft, pRight, 0);
-              if( pExpr==0 ) break;
-              setQuotedToken(pParse, &pLeft->token, zTabName);
-              setToken(&pExpr->span, 
-                  sqlite3MPrintf(db, "%s.%s", zTabName, zName));
-              pExpr->span.dyn = 1;
-              pExpr->token.z = 0;
-              pExpr->token.n = 0;
-              pExpr->token.dyn = 0;
-            }else{
-              pExpr = pRight;
-              pExpr->span = pExpr->token;
-              pExpr->span.dyn = 0;
-            }
-            if( longNames ){
-              pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pExpr->span);
-            }else{
-              pNew = sqlite3ExprListAppend(pParse, pNew, pExpr, &pRight->token);
-            }
-          }
-        }
-        if( !tableSeen ){
-          if( zTName ){
-            sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
-          }else{
-            sqlite3ErrorMsg(pParse, "no tables specified");
-          }
-          rc = 1;
-        }
-        sqlite3_free(zTName);
-      }
-    }
-    sqlite3ExprListDelete(pEList);
-    p->pEList = pNew;
-  }
-  if( p->pEList && p->pEList->nExpr>SQLITE_MAX_COLUMN ){
-    sqlite3ErrorMsg(pParse, "too many columns in result set");
-    rc = SQLITE_ERROR;
-  }
-  if( db->mallocFailed ){
-    rc = SQLITE_NOMEM;
-  }
-  return rc;
-}
-
-/*
-** pE is a pointer to an expression which is a single term in
-** ORDER BY or GROUP BY clause.
-**
-** If pE evaluates to an integer constant i, then return i.
-** This is an indication to the caller that it should sort
-** by the i-th column of the result set.
-**
-** If pE is a well-formed expression and the SELECT statement
-** is not compound, then return 0.  This indicates to the
-** caller that it should sort by the value of the ORDER BY
-** expression.
-**
-** If the SELECT is compound, then attempt to match pE against
-** result set columns in the left-most SELECT statement.  Return
-** the index i of the matching column, as an indication to the 
-** caller that it should sort by the i-th column.  If there is
-** no match, return -1 and leave an error message in pParse.
-*/
-static int matchOrderByTermToExprList(
-  Parse *pParse,     /* Parsing context for error messages */
-  Select *pSelect,   /* The SELECT statement with the ORDER BY clause */
-  Expr *pE,          /* The specific ORDER BY term */
-  int idx,           /* When ORDER BY term is this */
-  int isCompound,    /* True if this is a compound SELECT */
-  u8 *pHasAgg        /* True if expression contains aggregate functions */
-){
-  int i;             /* Loop counter */
-  ExprList *pEList;  /* The columns of the result set */
-  NameContext nc;    /* Name context for resolving pE */
-
-
-  /* If the term is an integer constant, return the value of that
-  ** constant */
-  pEList = pSelect->pEList;
-  if( sqlite3ExprIsInteger(pE, &i) ){
-    if( i<=0 ){
-      /* If i is too small, make it too big.  That way the calling
-      ** function still sees a value that is out of range, but does
-      ** not confuse the column number with 0 or -1 result code.
-      */
-      i = pEList->nExpr+1;
-    }
-    return i;
-  }
-
-  /* If the term is a simple identifier that try to match that identifier
-  ** against a column name in the result set.
-  */
-  if( pE->op==TK_ID || (pE->op==TK_STRING && pE->token.z[0]!='\'') ){
-    sqlite3 *db = pParse->db;
-    char *zCol = sqlite3NameFromToken(db, &pE->token);
-    if( zCol==0 ){
-      return -1;
-    }
-    for(i=0; i<pEList->nExpr; i++){
-      char *zAs = pEList->a[i].zName;
-      if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
-        sqlite3_free(zCol);
-        return i+1;
-      }
-    }
-    sqlite3_free(zCol);
-  }
-
-  /* Resolve all names in the ORDER BY term expression
-  */
-  memset(&nc, 0, sizeof(nc));
-  nc.pParse = pParse;
-  nc.pSrcList = pSelect->pSrc;
-  nc.pEList = pEList;
-  nc.allowAgg = 1;
-  nc.nErr = 0;
-  if( sqlite3ExprResolveNames(&nc, pE) ){
-    if( isCompound ){
-      sqlite3ErrorClear(pParse);
-      return 0;
-    }else{
-      return -1;
-    }
-  }
-  if( nc.hasAgg && pHasAgg ){
-    *pHasAgg = 1;
-  }
-
-  /* For a compound SELECT, we need to try to match the ORDER BY
-  ** expression against an expression in the result set
-  */
-  if( isCompound ){
-    for(i=0; i<pEList->nExpr; i++){
-      if( sqlite3ExprCompare(pEList->a[i].pExpr, pE) ){
-        return i+1;
-      }
-    }
-  }
-  return 0;
-}
-
-
-/*
-** Analyze and ORDER BY or GROUP BY clause in a simple SELECT statement.
-** Return the number of errors seen.
-**
-** Every term of the ORDER BY or GROUP BY clause needs to be an
-** expression.  If any expression is an integer constant, then
-** that expression is replaced by the corresponding 
-** expression from the result set.
-*/
-static int processOrderGroupBy(
-  Parse *pParse,        /* Parsing context.  Leave error messages here */
-  Select *pSelect,      /* The SELECT statement containing the clause */
-  ExprList *pOrderBy,   /* The ORDER BY or GROUP BY clause to be processed */
-  int isOrder,          /* 1 for ORDER BY.  0 for GROUP BY */
-  u8 *pHasAgg           /* Set to TRUE if any term contains an aggregate */
-){
-  int i;
-  sqlite3 *db = pParse->db;
-  ExprList *pEList;
-
-  if( pOrderBy==0 ) return 0;
-  if( pOrderBy->nExpr>SQLITE_MAX_COLUMN ){
-    const char *zType = isOrder ? "ORDER" : "GROUP";
-    sqlite3ErrorMsg(pParse, "too many terms in %s BY clause", zType);
-    return 1;
-  }
-  pEList = pSelect->pEList;
-  if( pEList==0 ){
-    return 0;
-  }
-  for(i=0; i<pOrderBy->nExpr; i++){
-    int iCol;
-    Expr *pE = pOrderBy->a[i].pExpr;
-    iCol = matchOrderByTermToExprList(pParse, pSelect, pE, i+1, 0, pHasAgg);
-    if( iCol<0 ){
-      return 1;
-    }
-    if( iCol>pEList->nExpr ){
-      const char *zType = isOrder ? "ORDER" : "GROUP";
-      sqlite3ErrorMsg(pParse, 
-         "%r %s BY term out of range - should be "
-         "between 1 and %d", i+1, zType, pEList->nExpr);
-      return 1;
-    }
-    if( iCol>0 ){
-      CollSeq *pColl = pE->pColl;
-      int flags = pE->flags & EP_ExpCollate;
-      sqlite3ExprDelete(pE);
-      pE = sqlite3ExprDup(db, pEList->a[iCol-1].pExpr);
-      pOrderBy->a[i].pExpr = pE;
-      if( pColl && flags ){
-        pE->pColl = pColl;
-        pE->flags |= flags;
-      }
-    }
-  }
-  return 0;
-}
-
-/*
-** Analyze and ORDER BY or GROUP BY clause in a SELECT statement.  Return
-** the number of errors seen.
-**
-** The processing depends on whether the SELECT is simple or compound.
-** For a simple SELECT statement, evry term of the ORDER BY or GROUP BY
-** clause needs to be an expression.  If any expression is an integer
-** constant, then that expression is replaced by the corresponding 
-** expression from the result set.
-**
-** For compound SELECT statements, every expression needs to be of
-** type TK_COLUMN with a iTable value as given in the 4th parameter.
-** If any expression is an integer, that becomes the column number.
-** Otherwise, match the expression against result set columns from
-** the left-most SELECT.
-*/
-static int processCompoundOrderBy(
-  Parse *pParse,        /* Parsing context.  Leave error messages here */
-  Select *pSelect,      /* The SELECT statement containing the ORDER BY */
-  int iTable            /* Output table for compound SELECT statements */
-){
-  int i;
-  ExprList *pOrderBy;
-  ExprList *pEList;
-  sqlite3 *db;
-  int moreToDo = 1;
-
-  pOrderBy = pSelect->pOrderBy;
-  if( pOrderBy==0 ) return 0;
-  if( pOrderBy->nExpr>SQLITE_MAX_COLUMN ){
-    sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause");
-    return 1;
-  }
-  db = pParse->db;
-  for(i=0; i<pOrderBy->nExpr; i++){
-    pOrderBy->a[i].done = 0;
-  }
-  while( pSelect->pPrior ){
-    pSelect = pSelect->pPrior;
-  }
-  while( pSelect && moreToDo ){
-    moreToDo = 0;
-    for(i=0; i<pOrderBy->nExpr; i++){
-      int iCol;
-      Expr *pE, *pDup;
-      if( pOrderBy->a[i].done ) continue;
-      pE = pOrderBy->a[i].pExpr;
-      pDup = sqlite3ExprDup(db, pE);
-      if( pDup==0 ){
-        return 1;
-      }
-      iCol = matchOrderByTermToExprList(pParse, pSelect, pDup, i+1, 1, 0);
-      sqlite3ExprDelete(pDup);
-      if( iCol<0 ){
-        return 1;
-      }
-      pEList = pSelect->pEList;
-      if( pEList==0 ){
-        return 1;
-      }
-      if( iCol>pEList->nExpr ){
-        sqlite3ErrorMsg(pParse, 
-           "%r ORDER BY term out of range - should be "
-           "between 1 and %d", i+1, pEList->nExpr);
-        return 1;
-      }
-      if( iCol>0 ){
-        pE->op = TK_COLUMN;
-        pE->iTable = iTable;
-        pE->iAgg = -1;
-        pE->iColumn = iCol-1;
-        pE->pTab = 0;
-        pOrderBy->a[i].done = 1;
-      }else{
-        moreToDo = 1;
-      }
-    }
-    pSelect = pSelect->pNext;
-  }
-  for(i=0; i<pOrderBy->nExpr; i++){
-    if( pOrderBy->a[i].done==0 ){
-      sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any "
-            "column in the result set", i+1);
-      return 1;
-    }
-  }
-  return 0;
-}
-
-/*
-** Get a VDBE for the given parser context.  Create a new one if necessary.
-** If an error occurs, return NULL and leave a message in pParse.
-*/
-Vdbe *sqlite3GetVdbe(Parse *pParse){
-  Vdbe *v = pParse->pVdbe;
-  if( v==0 ){
-    v = pParse->pVdbe = sqlite3VdbeCreate(pParse->db);
-  }
-  return v;
-}
-
-
-/*
-** Compute the iLimit and iOffset fields of the SELECT based on the
-** pLimit and pOffset expressions.  pLimit and pOffset hold the expressions
-** that appear in the original SQL statement after the LIMIT and OFFSET
-** keywords.  Or NULL 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 limit and/or offset, then 
-** iLimit and iOffset are negative.
-**
-** This routine changes the values of iLimit and iOffset only if
-** a limit or offset is defined by pLimit and pOffset.  iLimit and
-** iOffset should have been preset to appropriate default values
-** (usually but not always -1) prior to calling this routine.
-** Only if pLimit!=0 or pOffset!=0 do the limit registers get
-** redefined.  The UNION ALL operator uses this property to force
-** the reuse of the same limit and offset registers across multiple
-** SELECT statements.
-*/
-static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
-  Vdbe *v = 0;
-  int iLimit = 0;
-  int iOffset;
-  int addr1, addr2;
-
-  /* 
-  ** "LIMIT -1" always shows all rows.  There is some
-  ** contraversy about what the correct behavior should be.
-  ** The current implementation interprets "LIMIT 0" to mean
-  ** no rows.
-  */
-  if( p->pLimit ){
-    p->iLimit = iLimit = pParse->nMem;
-    pParse->nMem += 2;
-    v = sqlite3GetVdbe(pParse);
-    if( v==0 ) return;
-    sqlite3ExprCode(pParse, p->pLimit);
-    sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
-    sqlite3VdbeAddOp(v, OP_MemStore, iLimit, 1);
-    VdbeComment((v, "# LIMIT counter"));
-    sqlite3VdbeAddOp(v, OP_IfMemZero, iLimit, iBreak);
-    sqlite3VdbeAddOp(v, OP_MemLoad, iLimit, 0);
-  }
-  if( p->pOffset ){
-    p->iOffset = iOffset = pParse->nMem++;
-    v = sqlite3GetVdbe(pParse);
-    if( v==0 ) return;
-    sqlite3ExprCode(pParse, p->pOffset);
-    sqlite3VdbeAddOp(v, OP_MustBeInt, 0, 0);
-    sqlite3VdbeAddOp(v, OP_MemStore, iOffset, p->pLimit==0);
-    VdbeComment((v, "# OFFSET counter"));
-    addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iOffset, 0);
-    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
-    sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
-    sqlite3VdbeJumpHere(v, addr1);
-    if( p->pLimit ){
-      sqlite3VdbeAddOp(v, OP_Add, 0, 0);
-    }
-  }
-  if( p->pLimit ){
-    addr1 = sqlite3VdbeAddOp(v, OP_IfMemPos, iLimit, 0);
-    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
-    sqlite3VdbeAddOp(v, OP_MemInt, -1, iLimit+1);
-    addr2 = sqlite3VdbeAddOp(v, OP_Goto, 0, 0);
-    sqlite3VdbeJumpHere(v, addr1);
-    sqlite3VdbeAddOp(v, OP_MemStore, iLimit+1, 1);
-    VdbeComment((v, "# LIMIT+OFFSET"));
-    sqlite3VdbeJumpHere(v, addr2);
-  }
-}
-
-/*
-** Allocate a virtual index to use for sorting.
-*/
-static void createSortingIndex(Parse *pParse, Select *p, ExprList *pOrderBy){
-  if( pOrderBy ){
-    int addr;
-    assert( pOrderBy->iECursor==0 );
-    pOrderBy->iECursor = pParse->nTab++;
-    addr = sqlite3VdbeAddOp(pParse->pVdbe, OP_OpenEphemeral,
-                            pOrderBy->iECursor, pOrderBy->nExpr+1);
-    assert( p->addrOpenEphm[2] == -1 );
-    p->addrOpenEphm[2] = addr;
-  }
-}
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-/*
-** Return the appropriate collating sequence for the iCol-th column of
-** the result set for the compound-select statement "p".  Return NULL if
-** the column has no default collating sequence.
-**
-** The collating sequence for the compound select is taken from the
-** left-most term of the select that has a collating sequence.
-*/
-static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){
-  CollSeq *pRet;
-  if( p->pPrior ){
-    pRet = multiSelectCollSeq(pParse, p->pPrior, iCol);
-  }else{
-    pRet = 0;
-  }
-  if( pRet==0 ){
-    pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr);
-  }
-  return pRet;
-}
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-/*
-** This routine is called to process a query that is really the union
-** or intersection of two or more separate queries.
-**
-** "p" points to the right-most of the two queries.  the query on the
-** left is p->pPrior.  The left query could also be a compound query
-** in which case this routine will be called recursively. 
-**
-** The results of the total query are to be written into a destination
-** of type eDest with parameter iParm.
-**
-** Example 1:  Consider a three-way compound SQL statement.
-**
-**     SELECT a FROM t1 UNION SELECT b FROM t2 UNION SELECT c FROM t3
-**
-** This statement is parsed up as follows:
-**
-**     SELECT c FROM t3
-**      |
-**      `----->  SELECT b FROM t2
-**                |
-**                `------>  SELECT a FROM t1
-**
-** The arrows in the diagram above represent the Select.pPrior pointer.
-** So if this routine is called with p equal to the t3 query, then
-** pPrior will be the t2 query.  p->op will be TK_UNION in this case.
-**
-** Notice that because of the way SQLite parses compound SELECTs, the
-** individual selects always group from left to right.
-*/
-static int multiSelect(
-  Parse *pParse,        /* Parsing context */
-  Select *p,            /* The right-most of SELECTs to be coded */
-  int eDest,            /* \___  Store query results as specified */
-  int iParm,            /* /     by these two parameters.         */
-  char *aff             /* If eDest is SRT_Union, the affinity string */
-){
-  int rc = SQLITE_OK;   /* Success code from a subroutine */
-  Select *pPrior;       /* Another SELECT immediately to our left */
-  Vdbe *v;              /* Generate code to this VDBE */
-  int nCol;             /* Number of columns in the result set */
-  ExprList *pOrderBy;   /* The ORDER BY clause on p */
-  int aSetP2[2];        /* Set P2 value of these op to number of columns */
-  int nSetP2 = 0;       /* Number of slots in aSetP2[] used */
-
-  /* Make sure there is no ORDER BY or LIMIT clause on prior SELECTs.  Only
-  ** the last (right-most) SELECT in the series may have an ORDER BY or LIMIT.
-  */
-  if( p==0 || p->pPrior==0 ){
-    rc = 1;
-    goto multi_select_end;
-  }
-  pPrior = p->pPrior;
-  assert( pPrior->pRightmost!=pPrior );
-  assert( pPrior->pRightmost==p->pRightmost );
-  if( pPrior->pOrderBy ){
-    sqlite3ErrorMsg(pParse,"ORDER BY clause should come after %s not before",
-      selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
-  if( pPrior->pLimit ){
-    sqlite3ErrorMsg(pParse,"LIMIT clause should come after %s not before",
-      selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
-
-  /* Make sure we have a valid query engine.  If not, create a new one.
-  */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ){
-    rc = 1;
-    goto multi_select_end;
-  }
-
-  /* Create the destination temporary table if necessary
-  */
-  if( eDest==SRT_EphemTab ){
-    assert( p->pEList );
-    assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
-    aSetP2[nSetP2++] = sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, 0);
-    eDest = SRT_Table;
-  }
-
-  /* Generate code for the left and right SELECT statements.
-  */
-  pOrderBy = p->pOrderBy;
-  switch( p->op ){
-    case TK_ALL: {
-      if( pOrderBy==0 ){
-        int addr = 0;
-        assert( !pPrior->pLimit );
-        pPrior->pLimit = p->pLimit;
-        pPrior->pOffset = p->pOffset;
-        rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0, aff);
-        p->pLimit = 0;
-        p->pOffset = 0;
-        if( rc ){
-          goto multi_select_end;
-        }
-        p->pPrior = 0;
-        p->iLimit = pPrior->iLimit;
-        p->iOffset = pPrior->iOffset;
-        if( p->iLimit>=0 ){
-          addr = sqlite3VdbeAddOp(v, OP_IfMemZero, p->iLimit, 0);
-          VdbeComment((v, "# Jump ahead if LIMIT reached"));
-        }
-        rc = sqlite3Select(pParse, p, eDest, iParm, 0, 0, 0, aff);
-        p->pPrior = pPrior;
-        if( rc ){
-          goto multi_select_end;
-        }
-        if( addr ){
-          sqlite3VdbeJumpHere(v, addr);
-        }
-        break;
-      }
-      /* For UNION ALL ... ORDER BY fall through to the next case */
-    }
-    case TK_EXCEPT:
-    case TK_UNION: {
-      int unionTab;    /* Cursor number of the temporary table holding result */
-      int op = 0;      /* One of the SRT_ operations to apply to self */
-      int priorOp;     /* The SRT_ operation to apply to prior selects */
-      Expr *pLimit, *pOffset; /* Saved values of p->nLimit and p->nOffset */
-      int addr;
-
-      priorOp = p->op==TK_ALL ? SRT_Table : SRT_Union;
-      if( eDest==priorOp && pOrderBy==0 && !p->pLimit && !p->pOffset ){
-        /* We can reuse a temporary table generated by a SELECT to our
-        ** right.
-        */
-        unionTab = iParm;
-      }else{
-        /* We will need to create our own temporary table to hold the
-        ** intermediate results.
-        */
-        unionTab = pParse->nTab++;
-        if( processCompoundOrderBy(pParse, p, unionTab) ){
-          rc = 1;
-          goto multi_select_end;
-        }
-        addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, unionTab, 0);
-        if( priorOp==SRT_Table ){
-          assert( nSetP2<sizeof(aSetP2)/sizeof(aSetP2[0]) );
-          aSetP2[nSetP2++] = addr;
-        }else{
-          assert( p->addrOpenEphm[0] == -1 );
-          p->addrOpenEphm[0] = addr;
-          p->pRightmost->usesEphm = 1;
-        }
-        createSortingIndex(pParse, p, pOrderBy);
-        assert( p->pEList );
-      }
-
-      /* Code the SELECT statements to our left
-      */
-      assert( !pPrior->pOrderBy );
-      rc = sqlite3Select(pParse, pPrior, priorOp, unionTab, 0, 0, 0, aff);
-      if( rc ){
-        goto multi_select_end;
-      }
-
-      /* Code the current SELECT statement
-      */
-      switch( p->op ){
-         case TK_EXCEPT:  op = SRT_Except;   break;
-         case TK_UNION:   op = SRT_Union;    break;
-         case TK_ALL:     op = SRT_Table;    break;
-      }
-      p->pPrior = 0;
-      p->pOrderBy = 0;
-      p->disallowOrderBy = pOrderBy!=0;
-      pLimit = p->pLimit;
-      p->pLimit = 0;
-      pOffset = p->pOffset;
-      p->pOffset = 0;
-      rc = sqlite3Select(pParse, p, op, unionTab, 0, 0, 0, aff);
-      /* Query flattening in sqlite3Select() might refill p->pOrderBy.
-      ** Be sure to delete p->pOrderBy, therefore, to avoid a memory leak. */
-      sqlite3ExprListDelete(p->pOrderBy);
-      p->pPrior = pPrior;
-      p->pOrderBy = pOrderBy;
-      sqlite3ExprDelete(p->pLimit);
-      p->pLimit = pLimit;
-      p->pOffset = pOffset;
-      p->iLimit = -1;
-      p->iOffset = -1;
-      if( rc ){
-        goto multi_select_end;
-      }
-
-
-      /* Convert the data in the temporary table into whatever form
-      ** it is that we currently need.
-      */      
-      if( eDest!=priorOp || unionTab!=iParm ){
-        int iCont, iBreak, iStart;
-        assert( p->pEList );
-        if( eDest==SRT_Callback ){
-          Select *pFirst = p;
-          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-          generateColumnNames(pParse, 0, pFirst->pEList);
-        }
-        iBreak = sqlite3VdbeMakeLabel(v);
-        iCont = sqlite3VdbeMakeLabel(v);
-        computeLimitRegisters(pParse, p, iBreak);
-        sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
-        iStart = sqlite3VdbeCurrentAddr(v);
-        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
-                             pOrderBy, -1, eDest, iParm, 
-                             iCont, iBreak, 0);
-        if( rc ){
-          rc = 1;
-          goto multi_select_end;
-        }
-        sqlite3VdbeResolveLabel(v, iCont);
-        sqlite3VdbeAddOp(v, OP_Next, unionTab, iStart);
-        sqlite3VdbeResolveLabel(v, iBreak);
-        sqlite3VdbeAddOp(v, OP_Close, unionTab, 0);
-      }
-      break;
-    }
-    case TK_INTERSECT: {
-      int tab1, tab2;
-      int iCont, iBreak, iStart;
-      Expr *pLimit, *pOffset;
-      int addr;
-
-      /* INTERSECT is different from the others since it requires
-      ** two temporary tables.  Hence it has its own case.  Begin
-      ** by allocating the tables we will need.
-      */
-      tab1 = pParse->nTab++;
-      tab2 = pParse->nTab++;
-      if( processCompoundOrderBy(pParse, p, tab1) ){
-        rc = 1;
-        goto multi_select_end;
-      }
-      createSortingIndex(pParse, p, pOrderBy);
-
-      addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab1, 0);
-      assert( p->addrOpenEphm[0] == -1 );
-      p->addrOpenEphm[0] = addr;
-      p->pRightmost->usesEphm = 1;
-      assert( p->pEList );
-
-      /* Code the SELECTs to our left into temporary table "tab1".
-      */
-      rc = sqlite3Select(pParse, pPrior, SRT_Union, tab1, 0, 0, 0, aff);
-      if( rc ){
-        goto multi_select_end;
-      }
-
-      /* Code the current SELECT into temporary table "tab2"
-      */
-      addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, tab2, 0);
-      assert( p->addrOpenEphm[1] == -1 );
-      p->addrOpenEphm[1] = addr;
-      p->pPrior = 0;
-      pLimit = p->pLimit;
-      p->pLimit = 0;
-      pOffset = p->pOffset;
-      p->pOffset = 0;
-      rc = sqlite3Select(pParse, p, SRT_Union, tab2, 0, 0, 0, aff);
-      p->pPrior = pPrior;
-      sqlite3ExprDelete(p->pLimit);
-      p->pLimit = pLimit;
-      p->pOffset = pOffset;
-      if( rc ){
-        goto multi_select_end;
-      }
-
-      /* Generate code to take the intersection of the two temporary
-      ** tables.
-      */
-      assert( p->pEList );
-      if( eDest==SRT_Callback ){
-        Select *pFirst = p;
-        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
-        generateColumnNames(pParse, 0, pFirst->pEList);
-      }
-      iBreak = sqlite3VdbeMakeLabel(v);
-      iCont = sqlite3VdbeMakeLabel(v);
-      computeLimitRegisters(pParse, p, iBreak);
-      sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
-      iStart = sqlite3VdbeAddOp(v, OP_RowKey, tab1, 0);
-      sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
-      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
-                             pOrderBy, -1, eDest, iParm, 
-                             iCont, iBreak, 0);
-      if( rc ){
-        rc = 1;
-        goto multi_select_end;
-      }
-      sqlite3VdbeResolveLabel(v, iCont);
-      sqlite3VdbeAddOp(v, OP_Next, tab1, iStart);
-      sqlite3VdbeResolveLabel(v, iBreak);
-      sqlite3VdbeAddOp(v, OP_Close, tab2, 0);
-      sqlite3VdbeAddOp(v, OP_Close, tab1, 0);
-      break;
-    }
-  }
-
-  /* Make sure all SELECTs in the statement have the same number of elements
-  ** in their result sets.
-  */
-  assert( p->pEList && pPrior->pEList );
-  if( p->pEList->nExpr!=pPrior->pEList->nExpr ){
-    sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s"
-      " do not have the same number of result columns", selectOpName(p->op));
-    rc = 1;
-    goto multi_select_end;
-  }
-
-  /* Set the number of columns in temporary tables
-  */
-  nCol = p->pEList->nExpr;
-  while( nSetP2 ){
-    sqlite3VdbeChangeP2(v, aSetP2[--nSetP2], nCol);
-  }
-
-  /* Compute collating sequences used by either the ORDER BY clause or
-  ** by any temporary tables needed to implement the compound select.
-  ** Attach the KeyInfo structure to all temporary tables.  Invoke the
-  ** ORDER BY processing if there is an ORDER BY clause.
-  **
-  ** This section is run by the right-most SELECT statement only.
-  ** SELECT statements to the left always skip this part.  The right-most
-  ** SELECT might also skip this part if it has no ORDER BY clause and
-  ** no temp tables are required.
-  */
-  if( pOrderBy || p->usesEphm ){
-    int i;                        /* Loop counter */
-    KeyInfo *pKeyInfo;            /* Collating sequence for the result set */
-    Select *pLoop;                /* For looping through SELECT statements */
-    int nKeyCol;                  /* Number of entries in pKeyInfo->aCol[] */
-    CollSeq **apColl;             /* For looping through pKeyInfo->aColl[] */
-    CollSeq **aCopy;              /* A copy of pKeyInfo->aColl[] */
-
-    assert( p->pRightmost==p );
-    nKeyCol = nCol + (pOrderBy ? pOrderBy->nExpr : 0);
-    pKeyInfo = (KeyInfo*)sqlite3DbMallocZero(pParse->db,
-                       sizeof(*pKeyInfo)+nKeyCol*(sizeof(CollSeq*) + 1));
-    if( !pKeyInfo ){
-      rc = SQLITE_NOMEM;
-      goto multi_select_end;
-    }
-
-    pKeyInfo->enc = ENC(pParse->db);
-    pKeyInfo->nField = nCol;
-
-    for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
-      *apColl = multiSelectCollSeq(pParse, p, i);
-      if( 0==*apColl ){
-        *apColl = pParse->db->pDfltColl;
-      }
-    }
-
-    for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
-      for(i=0; i<2; i++){
-        int addr = pLoop->addrOpenEphm[i];
-        if( addr<0 ){
-          /* If [0] is unused then [1] is also unused.  So we can
-          ** always safely abort as soon as the first unused slot is found */
-          assert( pLoop->addrOpenEphm[1]<0 );
-          break;
-        }
-        sqlite3VdbeChangeP2(v, addr, nCol);
-        sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO);
-        pLoop->addrOpenEphm[i] = -1;
-      }
-    }
-
-    if( pOrderBy ){
-		ExprList::ExprList_item *pOTerm = pOrderBy->a;
-      int nOrderByExpr = pOrderBy->nExpr;
-      int addr;
-      u8 *pSortOrder;
-
-      /* Reuse the same pKeyInfo for the ORDER BY as was used above for
-      ** the compound select statements.  Except we have to change out the
-      ** pKeyInfo->aColl[] values.  Some of the aColl[] values will be
-      ** reused when constructing the pKeyInfo for the ORDER BY, so make
-      ** a copy.  Sufficient space to hold both the nCol entries for
-      ** the compound select and the nOrderbyExpr entries for the ORDER BY
-      ** was allocated above.  But we need to move the compound select
-      ** entries out of the way before constructing the ORDER BY entries.
-      ** Move the compound select entries into aCopy[] where they can be
-      ** accessed and reused when constructing the ORDER BY entries.
-      ** Because nCol might be greater than or less than nOrderByExpr
-      ** we have to use memmove() when doing the copy.
-      */
-      aCopy = &pKeyInfo->aColl[nOrderByExpr];
-      pSortOrder = pKeyInfo->aSortOrder = (u8*)&aCopy[nCol];
-      memmove(aCopy, pKeyInfo->aColl, nCol*sizeof(CollSeq*));
-
-      apColl = pKeyInfo->aColl;
-      for(i=0; i<nOrderByExpr; i++, pOTerm++, apColl++, pSortOrder++){
-        Expr *pExpr = pOTerm->pExpr;
-        if( (pExpr->flags & EP_ExpCollate) ){
-          assert( pExpr->pColl!=0 );
-          *apColl = pExpr->pColl;
-        }else{
-          *apColl = aCopy[pExpr->iColumn];
-        }
-        *pSortOrder = pOTerm->sortOrder;
-      }
-      assert( p->pRightmost==p );
-      assert( p->addrOpenEphm[2]>=0 );
-      addr = p->addrOpenEphm[2];
-      sqlite3VdbeChangeP2(v, addr, p->pOrderBy->nExpr+2);
-      pKeyInfo->nField = nOrderByExpr;
-      sqlite3VdbeChangeP3(v, addr, (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
-      pKeyInfo = 0;
-      generateSortTail(pParse, p, v, p->pEList->nExpr, eDest, iParm);
-    }
-
-    sqlite3_free(pKeyInfo);
-  }
-
-multi_select_end:
-  return rc;
-}
-#endif /* SQLITE_OMIT_COMPOUND_SELECT */
-
-#ifndef SQLITE_OMIT_VIEW
-/* Forward Declarations */
-static void substExprList(sqlite3*, ExprList*, int, ExprList*);
-static void substSelect(sqlite3*, Select *, int, ExprList *);
-
-/*
-** Scan through the expression pExpr.  Replace every reference to
-** a column in table number iTable with a copy of the iColumn-th
-** entry in pEList.  (But leave references to the ROWID column 
-** unchanged.)
-**
-** This routine is part of the flattening procedure.  A subquery
-** whose result set is defined by pEList appears as entry in the
-** FROM clause of a SELECT such that the VDBE cursor assigned to that
-** FORM clause entry is iTable.  This routine make the necessary 
-** changes to pExpr so that it refers directly to the source table
-** of the subquery rather the result set of the subquery.
-*/
-static void substExpr(
-  sqlite3 *db,        /* Report malloc errors to this connection */
-  Expr *pExpr,        /* Expr in which substitution occurs */
-  int iTable,         /* Table to be substituted */
-  ExprList *pEList    /* Substitute expressions */
-){
-  if( pExpr==0 ) return;
-  if( pExpr->op==TK_COLUMN && pExpr->iTable==iTable ){
-    if( pExpr->iColumn<0 ){
-      pExpr->op = TK_NULL;
-    }else{
-      Expr *pNew;
-      assert( pEList!=0 && pExpr->iColumn<pEList->nExpr );
-      assert( pExpr->pLeft==0 && pExpr->pRight==0 && pExpr->pList==0 );
-      pNew = pEList->a[pExpr->iColumn].pExpr;
-      assert( pNew!=0 );
-      pExpr->op = pNew->op;
-      assert( pExpr->pLeft==0 );
-      pExpr->pLeft = sqlite3ExprDup(db, pNew->pLeft);
-      assert( pExpr->pRight==0 );
-      pExpr->pRight = sqlite3ExprDup(db, pNew->pRight);
-      assert( pExpr->pList==0 );
-      pExpr->pList = sqlite3ExprListDup(db, pNew->pList);
-      pExpr->iTable = pNew->iTable;
-      pExpr->pTab = pNew->pTab;
-      pExpr->iColumn = pNew->iColumn;
-      pExpr->iAgg = pNew->iAgg;
-      sqlite3TokenCopy(db, &pExpr->token, &pNew->token);
-      sqlite3TokenCopy(db, &pExpr->span, &pNew->span);
-      pExpr->pSelect = sqlite3SelectDup(db, pNew->pSelect);
-      pExpr->flags = pNew->flags;
-    }
-  }else{
-    substExpr(db, pExpr->pLeft, iTable, pEList);
-    substExpr(db, pExpr->pRight, iTable, pEList);
-    substSelect(db, pExpr->pSelect, iTable, pEList);
-    substExprList(db, pExpr->pList, iTable, pEList);
-  }
-}
-static void substExprList(
-  sqlite3 *db,         /* Report malloc errors here */
-  ExprList *pList,     /* List to scan and in which to make substitutes */
-  int iTable,          /* Table to be substituted */
-  ExprList *pEList     /* Substitute values */
-){
-  int i;
-  if( pList==0 ) return;
-  for(i=0; i<pList->nExpr; i++){
-    substExpr(db, pList->a[i].pExpr, iTable, pEList);
-  }
-}
-static void substSelect(
-  sqlite3 *db,         /* Report malloc errors here */
-  Select *p,           /* SELECT statement in which to make substitutions */
-  int iTable,          /* Table to be replaced */
-  ExprList *pEList     /* Substitute values */
-){
-  if( !p ) return;
-  substExprList(db, p->pEList, iTable, pEList);
-  substExprList(db, p->pGroupBy, iTable, pEList);
-  substExprList(db, p->pOrderBy, iTable, pEList);
-  substExpr(db, p->pHaving, iTable, pEList);
-  substExpr(db, p->pWhere, iTable, pEList);
-  substSelect(db, p->pPrior, iTable, pEList);
-}
-#endif /* !defined(SQLITE_OMIT_VIEW) */
-
-#ifndef SQLITE_OMIT_VIEW
-/*
-** This routine attempts to flatten subqueries in order to speed
-** execution.  It returns 1 if it makes changes and 0 if no flattening
-** occurs.
-**
-** To understand the concept of flattening, consider the following
-** query:
-**
-**     SELECT a FROM (SELECT x+y AS a FROM t1 WHERE z<100) WHERE a>5
-**
-** The default way of implementing this query is to execute the
-** subquery first and store the results in a temporary table, then
-** run the outer query on that temporary table.  This requires two
-** passes over the data.  Furthermore, because the temporary table
-** has no indices, the WHERE clause on the outer query cannot be
-** optimized.
-**
-** This routine attempts to rewrite queries such as the above into
-** a single flat select, like this:
-**
-**     SELECT x+y AS a FROM t1 WHERE z<100 AND a>5
-**
-** The code generated for this simpification gives the same result
-** but only has to scan the data once.  And because indices might 
-** exist on the table t1, a complete scan of the data might be
-** avoided.
-**
-** Flattening is only attempted if all of the following are true:
-**
-**   (1)  The subquery and the outer query do not both use aggregates.
-**
-**   (2)  The subquery is not an aggregate or the outer query is not a join.
-**
-**   (3)  The subquery is not the right operand of a left outer join, or
-**        the subquery is not itself a join.  (Ticket #306)
-**
-**   (4)  The subquery is not DISTINCT or the outer query is not a join.
-**
-**   (5)  The subquery is not DISTINCT or the outer query does not use
-**        aggregates.
-**
-**   (6)  The subquery does not use aggregates or the outer query is not
-**        DISTINCT.
-**
-**   (7)  The subquery has a FROM clause.
-**
-**   (8)  The subquery does not use LIMIT or the outer query is not a join.
-**
-**   (9)  The subquery does not use LIMIT or the outer query does not use
-**        aggregates.
-**
-**  (10)  The subquery does not use aggregates or the outer query does not
-**        use LIMIT.
-**
-**  (11)  The subquery and the outer query do not both have ORDER BY clauses.
-**
-**  (12)  The subquery is not the right term of a LEFT OUTER JOIN or the
-**        subquery has no WHERE clause.  (added by ticket #350)
-**
-**  (13)  The subquery and outer query do not both use LIMIT
-**
-**  (14)  The subquery does not use OFFSET
-**
-**  (15)  The outer query is not part of a compound select or the
-**        subquery does not have both an ORDER BY and a LIMIT clause.
-**        (See ticket #2339)
-**
-** In this routine, the "p" parameter is a pointer to the outer query.
-** The subquery is p->pSrc->a[iFrom].  isAgg is true if the outer query
-** uses aggregates and subqueryIsAgg is true if the subquery uses aggregates.
-**
-** If flattening is not attempted, this routine is a no-op and returns 0.
-** If flattening is attempted this routine returns 1.
-**
-** All of the expression analysis must occur on both the outer query and
-** the subquery before this routine runs.
-*/
-static int flattenSubquery(
-  sqlite3 *db,         /* Database connection */
-  Select *p,           /* The parent or outer SELECT statement */
-  int iFrom,           /* Index in p->pSrc->a[] of the inner subquery */
-  int isAgg,           /* True if outer SELECT uses aggregate functions */
-  int subqueryIsAgg    /* True if the subquery uses aggregate functions */
-){
-  Select *pSub;       /* The inner query or "subquery" */
-  SrcList *pSrc;      /* The FROM clause of the outer query */
-  SrcList *pSubSrc;   /* The FROM clause of the subquery */
-  ExprList *pList;    /* The result set of the outer query */
-  int iParent;        /* VDBE cursor number of the pSub result set temp table */
-  int i;              /* Loop counter */
-  Expr *pWhere;                    /* The WHERE clause */
-  SrcList::SrcList_item *pSubitem;   /* The subquery */
-
-  /* Check to see if flattening is permitted.  Return 0 if not.
-  */
-  if( p==0 ) return 0;
-  pSrc = p->pSrc;
-  assert( pSrc && iFrom>=0 && iFrom<pSrc->nSrc );
-  pSubitem = &pSrc->a[iFrom];
-  pSub = pSubitem->pSelect;
-  assert( pSub!=0 );
-  if( isAgg && subqueryIsAgg ) return 0;                 /* Restriction (1)  */
-  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;          /* Restriction (2)  */
-  pSubSrc = pSub->pSrc;
-  assert( pSubSrc );
-  /* Prior to version 3.1.2, when LIMIT and OFFSET had to be simple constants,
-  ** not arbitrary expresssions, we allowed some combining of LIMIT and OFFSET
-  ** because they could be computed at compile-time.  But when LIMIT and OFFSET
-  ** became arbitrary expressions, we were forced to add restrictions (13)
-  ** and (14). */
-  if( pSub->pLimit && p->pLimit ) return 0;              /* Restriction (13) */
-  if( pSub->pOffset ) return 0;                          /* Restriction (14) */
-  if( p->pRightmost && pSub->pLimit && pSub->pOrderBy ){
-    return 0;                                            /* Restriction (15) */
-  }
-  if( pSubSrc->nSrc==0 ) return 0;                       /* Restriction (7)  */
-  if( (pSub->isDistinct || pSub->pLimit) 
-         && (pSrc->nSrc>1 || isAgg) ){          /* Restrictions (4)(5)(8)(9) */
-     return 0;       
-  }
-  if( p->isDistinct && subqueryIsAgg ) return 0;         /* Restriction (6)  */
-  if( (p->disallowOrderBy || p->pOrderBy) && pSub->pOrderBy ){
-     return 0;                                           /* Restriction (11) */
-  }
-
-  /* Restriction 3:  If the subquery is a join, make sure the subquery is 
-  ** not used as the right operand of an outer join.  Examples of why this
-  ** is not allowed:
-  **
-  **         t1 LEFT OUTER JOIN (t2 JOIN t3)
-  **
-  ** If we flatten the above, we would get
-  **
-  **         (t1 LEFT OUTER JOIN t2) JOIN t3
-  **
-  ** which is not at all the same thing.
-  */
-  if( pSubSrc->nSrc>1 && (pSubitem->jointype & JT_OUTER)!=0 ){
-    return 0;
-  }
-
-  /* Restriction 12:  If the subquery is the right operand of a left outer
-  ** join, make sure the subquery has no WHERE clause.
-  ** An examples of why this is not allowed:
-  **
-  **         t1 LEFT OUTER JOIN (SELECT * FROM t2 WHERE t2.x>0)
-  **
-  ** If we flatten the above, we would get
-  **
-  **         (t1 LEFT OUTER JOIN t2) WHERE t2.x>0
-  **
-  ** But the t2.x>0 test will always fail on a NULL row of t2, which
-  ** effectively converts the OUTER JOIN into an INNER JOIN.
-  */
-  if( (pSubitem->jointype & JT_OUTER)!=0 && pSub->pWhere!=0 ){
-    return 0;
-  }
-
-  /* If we reach this point, it means flattening is permitted for the
-  ** iFrom-th entry of the FROM clause in the outer query.
-  */
-
-  /* Move all of the FROM elements of the subquery into the
-  ** the FROM clause of the outer query.  Before doing this, remember
-  ** the cursor number for the original outer query FROM element in
-  ** iParent.  The iParent cursor will never be used.  Subsequent code
-  ** will scan expressions looking for iParent references and replace
-  ** those references with expressions that resolve to the subquery FROM
-  ** elements we are now copying in.
-  */
-  iParent = pSubitem->iCursor;
-  {
-    int nSubSrc = pSubSrc->nSrc;
-    int jointype = pSubitem->jointype;
-
-    sqlite3DeleteTable(pSubitem->pTab);
-    sqlite3_free(pSubitem->zDatabase);
-    sqlite3_free(pSubitem->zName);
-    sqlite3_free(pSubitem->zAlias);
-    pSubitem->pTab = 0;
-    pSubitem->zDatabase = 0;
-    pSubitem->zName = 0;
-    pSubitem->zAlias = 0;
-    if( nSubSrc>1 ){
-      int extra = nSubSrc - 1;
-      for(i=1; i<nSubSrc; i++){
-        pSrc = sqlite3SrcListAppend(db, pSrc, 0, 0);
-        if( pSrc==0 ){
-          p->pSrc = 0;
-          return 1;
-        }
-      }
-      p->pSrc = pSrc;
-      for(i=pSrc->nSrc-1; i-extra>=iFrom; i--){
-        pSrc->a[i] = pSrc->a[i-extra];
-      }
-    }
-    for(i=0; i<nSubSrc; i++){
-      pSrc->a[i+iFrom] = pSubSrc->a[i];
-      memset(&pSubSrc->a[i], 0, sizeof(pSubSrc->a[i]));
-    }
-    pSrc->a[iFrom].jointype = jointype;
-  }
-
-  /* Now begin substituting subquery result set expressions for 
-  ** references to the iParent in the outer query.
-  ** 
-  ** Example:
-  **
-  **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
-  **   \                     \_____________ subquery __________/          /
-  **    \_____________________ outer query ______________________________/
-  **
-  ** We look at every expression in the outer query and every place we see
-  ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
-  */
-  pList = p->pEList;
-  for(i=0; i<pList->nExpr; i++){
-    Expr *pExpr;
-    if( pList->a[i].zName==0 && (pExpr = pList->a[i].pExpr)->span.z!=0 ){
-      pList->a[i].zName = 
-             sqlite3DbStrNDup(db, (char*)pExpr->span.z, pExpr->span.n);
-    }
-  }
-  substExprList(db, p->pEList, iParent, pSub->pEList);
-  if( isAgg ){
-    substExprList(db, p->pGroupBy, iParent, pSub->pEList);
-    substExpr(db, p->pHaving, iParent, pSub->pEList);
-  }
-  if( pSub->pOrderBy ){
-    assert( p->pOrderBy==0 );
-    p->pOrderBy = pSub->pOrderBy;
-    pSub->pOrderBy = 0;
-  }else if( p->pOrderBy ){
-    substExprList(db, p->pOrderBy, iParent, pSub->pEList);
-  }
-  if( pSub->pWhere ){
-    pWhere = sqlite3ExprDup(db, pSub->pWhere);
-  }else{
-    pWhere = 0;
-  }
-  if( subqueryIsAgg ){
-    assert( p->pHaving==0 );
-    p->pHaving = p->pWhere;
-    p->pWhere = pWhere;
-    substExpr(db, p->pHaving, iParent, pSub->pEList);
-    p->pHaving = sqlite3ExprAnd(db, p->pHaving, 
-                                sqlite3ExprDup(db, pSub->pHaving));
-    assert( p->pGroupBy==0 );
-    p->pGroupBy = sqlite3ExprListDup(db, pSub->pGroupBy);
-  }else{
-    substExpr(db, p->pWhere, iParent, pSub->pEList);
-    p->pWhere = sqlite3ExprAnd(db, p->pWhere, pWhere);
-  }
-
-  /* The flattened query is distinct if either the inner or the
-  ** outer query is distinct. 
-  */
-  p->isDistinct = p->isDistinct || pSub->isDistinct;
-
-  /*
-  ** SELECT ... FROM (SELECT ... LIMIT a OFFSET b) LIMIT x OFFSET y;
-  **
-  ** One is tempted to try to add a and b to combine the limits.  But this
-  ** does not work if either limit is negative.
-  */
-  if( pSub->pLimit ){
-    p->pLimit = pSub->pLimit;
-    pSub->pLimit = 0;
-  }
-
-  /* Finially, delete what is left of the subquery and return
-  ** success.
-  */
-  sqlite3SelectDelete(pSub);
-  return 1;
-}
-#endif /* SQLITE_OMIT_VIEW */
-
-/*
-** Analyze the SELECT statement passed in as an argument to see if it
-** is a simple min() or max() query.  If it is and this query can be
-** satisfied using a single seek to the beginning or end of an index,
-** then generate the code for this SELECT and return 1.  If this is not a 
-** simple min() or max() query, then return 0;
-**
-** A simply min() or max() query looks like this:
-**
-**    SELECT min(a) FROM table;
-**    SELECT max(a) FROM table;
-**
-** The query may have only a single table in its FROM argument.  There
-** can be no GROUP BY or HAVING or WHERE clauses.  The result set must
-** be the min() or max() of a single column of the table.  The column
-** in the min() or max() function must be indexed.
-**
-** The parameters to this routine are the same as for sqlite3Select().
-** See the header comment on that routine for additional information.
-*/
-static int simpleMinMaxQuery(Parse *pParse, Select *p, int eDest, int iParm){
-  Expr *pExpr;
-  int iCol;
-  Table *pTab;
-  Index *pIdx;
-  int base;
-  Vdbe *v;
-  int seekOp;
-  ExprList *pEList, *pList, eList;
-  ExprList::ExprList_item eListItem;
-  SrcList *pSrc;
-  int brk;
-  int iDb;
-
-  /* Check to see if this query is a simple min() or max() query.  Return
-  ** zero if it is  not.
-  */
-  if( p->pGroupBy || p->pHaving || p->pWhere ) return 0;
-  pSrc = p->pSrc;
-  if( pSrc->nSrc!=1 ) return 0;
-  pEList = p->pEList;
-  if( pEList->nExpr!=1 ) return 0;
-  pExpr = pEList->a[0].pExpr;
-  if( pExpr->op!=TK_AGG_FUNCTION ) return 0;
-  pList = pExpr->pList;
-  if( pList==0 || pList->nExpr!=1 ) return 0;
-  if( pExpr->token.n!=3 ) return 0;
-  if( sqlite3StrNICmp((char*)pExpr->token.z,"min",3)==0 ){
-    seekOp = OP_Rewind;
-  }else if( sqlite3StrNICmp((char*)pExpr->token.z,"max",3)==0 ){
-    seekOp = OP_Last;
-  }else{
-    return 0;
-  }
-  pExpr = pList->a[0].pExpr;
-  if( pExpr->op!=TK_COLUMN ) return 0;
-  iCol = pExpr->iColumn;
-  pTab = pSrc->a[0].pTab;
-
-  /* This optimization cannot be used with virtual tables. */
-  if( IsVirtual(pTab) ) return 0;
-
-  /* If we get to here, it means the query is of the correct form.
-  ** Check to make sure we have an index and make pIdx point to the
-  ** appropriate index.  If the min() or max() is on an INTEGER PRIMARY
-  ** key column, no index is necessary so set pIdx to NULL.  If no
-  ** usable index is found, return 0.
-  */
-  if( iCol<0 ){
-    pIdx = 0;
-  }else{
-    CollSeq *pColl = sqlite3ExprCollSeq(pParse, pExpr);
-    if( pColl==0 ) return 0;
-    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
-      assert( pIdx->nColumn>=1 );
-      if( pIdx->aiColumn[0]==iCol && 
-          0==sqlite3StrICmp(pIdx->azColl[0], pColl->zName) ){
-        break;
-      }
-    }
-    if( pIdx==0 ) return 0;
-  }
-
-  /* Identify column types if we will be using the callback.  This
-  ** step is skipped if the output is going to a table or a memory cell.
-  ** The column names have already been generated in the calling function.
-  */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ) return 0;
-
-  /* If the output is destined for a temporary table, open that table.
-  */
-  if( eDest==SRT_EphemTab ){
-    sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, 1);
-  }
-
-  /* Generating code to find the min or the max.  Basically all we have
-  ** to do is find the first or the last entry in the chosen index.  If
-  ** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
-  ** or last entry in the main table.
-  */
-  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
-  assert( iDb>=0 || pTab->isEphem );
-  sqlite3CodeVerifySchema(pParse, iDb);
-  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
-  base = pSrc->a[0].iCursor;
-  brk = sqlite3VdbeMakeLabel(v);
-  computeLimitRegisters(pParse, p, brk);
-  if( pSrc->a[0].pSelect==0 ){
-    sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
-  }
-  if( pIdx==0 ){
-    sqlite3VdbeAddOp(v, seekOp, base, 0);
-  }else{
-    /* Even though the cursor used to open the index here is closed
-    ** as soon as a single value has been read from it, allocate it
-    ** using (pParse->nTab++) to prevent the cursor id from being 
-    ** reused. This is important for statements of the form 
-    ** "INSERT INTO x SELECT max() FROM x".
-    */
-    int iIdx;
-    KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIdx);
-    iIdx = pParse->nTab++;
-    assert( pIdx->pSchema==pTab->pSchema );
-    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
-    sqlite3VdbeOp3(v, OP_OpenRead, iIdx, pIdx->tnum, 
-        (char*)pKey, P3_KEYINFO_HANDOFF);
-    if( seekOp==OP_Rewind ){
-      sqlite3VdbeAddOp(v, OP_Null, 0, 0);
-      sqlite3VdbeAddOp(v, OP_MakeRecord, 1, 0);
-      seekOp = OP_MoveGt;
-    }
-    if( pIdx->aSortOrder[0]==SQLITE_SO_DESC ){
-      /* Ticket #2514: invert the seek operator if we are using
-      ** a descending index. */
-      if( seekOp==OP_Last ){
-        seekOp = OP_Rewind;
-      }else{
-        assert( seekOp==OP_MoveGt );
-        seekOp = OP_MoveLt;
-      }
-    }
-    sqlite3VdbeAddOp(v, seekOp, iIdx, 0);
-    sqlite3VdbeAddOp(v, OP_IdxRowid, iIdx, 0);
-    sqlite3VdbeAddOp(v, OP_Close, iIdx, 0);
-    sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
-  }
-  eList.nExpr = 1;
-  memset(&eListItem, 0, sizeof(eListItem));
-  eList.a = &eListItem;
-  eList.a[0].pExpr = pExpr;
-  selectInnerLoop(pParse, p, &eList, 0, 0, 0, -1, eDest, iParm, brk, brk, 0);
-  sqlite3VdbeResolveLabel(v, brk);
-  sqlite3VdbeAddOp(v, OP_Close, base, 0);
-  
-  return 1;
-}
-
-/*
-** This routine resolves any names used in the result set of the
-** supplied SELECT statement. If the SELECT statement being resolved
-** is a sub-select, then pOuterNC is a pointer to the NameContext 
-** of the parent SELECT.
-*/
-int sqlite3SelectResolve(
-  Parse *pParse,         /* The parser context */
-  Select *p,             /* The SELECT statement being coded. */
-  NameContext *pOuterNC  /* The outer name context. May be NULL. */
-){
-  ExprList *pEList;          /* Result set. */
-  int i;                     /* For-loop variable used in multiple places */
-  NameContext sNC;           /* Local name-context */
-  ExprList *pGroupBy;        /* The group by clause */
-
-  /* If this routine has run before, return immediately. */
-  if( p->isResolved ){
-    assert( !pOuterNC );
-    return SQLITE_OK;
-  }
-  p->isResolved = 1;
-
-  /* If there have already been errors, do nothing. */
-  if( pParse->nErr>0 ){
-    return SQLITE_ERROR;
-  }
-
-  /* Prepare the select statement. This call will allocate all cursors
-  ** required to handle the tables and subqueries in the FROM clause.
-  */
-  if( prepSelectStmt(pParse, p) ){
-    return SQLITE_ERROR;
-  }
-
-  /* Resolve the expressions in the LIMIT and OFFSET clauses. These
-  ** are not allowed to refer to any names, so pass an empty NameContext.
-  */
-  memset(&sNC, 0, sizeof(sNC));
-  sNC.pParse = pParse;
-  if( sqlite3ExprResolveNames(&sNC, p->pLimit) ||
-      sqlite3ExprResolveNames(&sNC, p->pOffset) ){
-    return SQLITE_ERROR;
-  }
-
-  /* Set up the local name-context to pass to ExprResolveNames() to
-  ** resolve the expression-list.
-  */
-  sNC.allowAgg = 1;
-  sNC.pSrcList = p->pSrc;
-  sNC.pNext = pOuterNC;
-
-  /* Resolve names in the result set. */
-  pEList = p->pEList;
-  if( !pEList ) return SQLITE_ERROR;
-  for(i=0; i<pEList->nExpr; i++){
-    Expr *pX = pEList->a[i].pExpr;
-    if( sqlite3ExprResolveNames(&sNC, pX) ){
-      return SQLITE_ERROR;
-    }
-  }
-
-  /* If there are no aggregate functions in the result-set, and no GROUP BY 
-  ** expression, do not allow aggregates in any of the other expressions.
-  */
-  assert( !p->isAgg );
-  pGroupBy = p->pGroupBy;
-  if( pGroupBy || sNC.hasAgg ){
-    p->isAgg = 1;
-  }else{
-    sNC.allowAgg = 0;
-  }
-
-  /* If a HAVING clause is present, then there must be a GROUP BY clause.
-  */
-  if( p->pHaving && !pGroupBy ){
-    sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
-    return SQLITE_ERROR;
-  }
-
-  /* Add the expression list to the name-context before parsing the
-  ** other expressions in the SELECT statement. This is so that
-  ** expressions in the WHERE clause (etc.) can refer to expressions by
-  ** aliases in the result set.
-  **
-  ** Minor point: If this is the case, then the expression will be
-  ** re-evaluated for each reference to it.
-  */
-  sNC.pEList = p->pEList;
-  if( sqlite3ExprResolveNames(&sNC, p->pWhere) ||
-     sqlite3ExprResolveNames(&sNC, p->pHaving) ){
-    return SQLITE_ERROR;
-  }
-  if( p->pPrior==0 ){
-    if( processOrderGroupBy(pParse, p, p->pOrderBy, 1, &sNC.hasAgg) ){
-      return SQLITE_ERROR;
-    }
-  }
-  if( processOrderGroupBy(pParse, p, pGroupBy, 0, &sNC.hasAgg) ){
-    return SQLITE_ERROR;
-  }
-
-  if( pParse->db->mallocFailed ){
-    return SQLITE_NOMEM;
-  }
-
-  /* Make sure the GROUP BY clause does not contain aggregate functions.
-  */
-  if( pGroupBy ){
-	  ExprList::ExprList_item *pItem;
-  
-    for(i=0, pItem=pGroupBy->a; i<pGroupBy->nExpr; i++, pItem++){
-      if( ExprHasProperty(pItem->pExpr, EP_Agg) ){
-        sqlite3ErrorMsg(pParse, "aggregate functions are not allowed in "
-            "the GROUP BY clause");
-        return SQLITE_ERROR;
-      }
-    }
-  }
-
-  /* If this is one SELECT of a compound, be sure to resolve names
-  ** in the other SELECTs.
-  */
-  if( p->pPrior ){
-    return sqlite3SelectResolve(pParse, p->pPrior, pOuterNC);
-  }else{
-    return SQLITE_OK;
-  }
-}
-
-/*
-** Reset the aggregate accumulator.
-**
-** The aggregate accumulator is a set of memory cells that hold
-** intermediate results while calculating an aggregate.  This
-** routine simply stores NULLs in all of those memory cells.
-*/
-static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i=0;
-  AggInfo::AggInfo_func *pFunc;
-  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
-    return;
-  }
-  for(i=0; i<pAggInfo->nColumn; i++){
-    sqlite3VdbeAddOp(v, OP_MemNull, pAggInfo->aCol[i].iMem, 0);
-  }
-  for(pFunc=pAggInfo->aFunc, i=0; i<pAggInfo->nFunc; i++, pFunc++){
-    sqlite3VdbeAddOp(v, OP_MemNull, pFunc->iMem, 0);
-    if( pFunc->iDistinct>=0 ){
-      Expr *pE = pFunc->pExpr;
-      if( pE->pList==0 || pE->pList->nExpr!=1 ){
-        sqlite3ErrorMsg(pParse, "DISTINCT in aggregate must be followed "
-           "by an expression");
-        pFunc->iDistinct = -1;
-      }else{
-        KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->pList);
-        sqlite3VdbeOp3(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 
-                          (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
-      }
-    }
-  }
-}
-
-/*
-** Invoke the OP_AggFinalize opcode for every aggregate function
-** in the AggInfo structure.
-*/
-static void finalizeAggFunctions(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  AggInfo::AggInfo_func *pF;
-  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
-    ExprList *pList = pF->pExpr->pList;
-    sqlite3VdbeOp3(v, OP_AggFinal, pF->iMem, pList ? pList->nExpr : 0,
-                      (const char*)pF->pFunc, P3_FUNCDEF);
-  }
-}
-
-/*
-** Update the accumulator memory cells for an aggregate based on
-** the current cursor position.
-*/
-static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){
-  Vdbe *v = pParse->pVdbe;
-  int i;
-  AggInfo::AggInfo_func *pF;
-  AggInfo::AggInfo_col *pC;
-
-  pAggInfo->directMode = 1;
-  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
-    int nArg;
-    int addrNext = 0;
-    ExprList *pList = pF->pExpr->pList;
-    if( pList ){
-      nArg = pList->nExpr;
-      sqlite3ExprCodeExprList(pParse, pList);
-    }else{
-      nArg = 0;
-    }
-    if( pF->iDistinct>=0 ){
-      addrNext = sqlite3VdbeMakeLabel(v);
-      assert( nArg==1 );
-      codeDistinct(v, pF->iDistinct, addrNext, 1);
-    }
-    if( pF->pFunc->needCollSeq ){
-      CollSeq *pColl = 0;
-	  ExprList::ExprList_item *pItem;
-      int j;
-      assert( pList!=0 );  /* pList!=0 if pF->pFunc->needCollSeq is true */
-      for(j=0, pItem=pList->a; !pColl && j<nArg; j++, pItem++){
-        pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      }
-      if( !pColl ){
-        pColl = pParse->db->pDfltColl;
-      }
-      sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
-    }
-    sqlite3VdbeOp3(v, OP_AggStep, pF->iMem, nArg, (const char*)pF->pFunc, P3_FUNCDEF);
-    if( addrNext ){
-      sqlite3VdbeResolveLabel(v, addrNext);
-    }
-  }
-  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
-    sqlite3ExprCode(pParse, pC->pExpr);
-    sqlite3VdbeAddOp(v, OP_MemStore, pC->iMem, 1);
-  }
-  pAggInfo->directMode = 0;
-}
-
-
-/*
-** Generate code for the given SELECT statement.
-**
-** The results are distributed in various ways depending on the
-** value of eDest and iParm.
-**
-**     eDest Value       Result
-**     ------------    -------------------------------------------
-**     SRT_Callback    Invoke the callback for each row of the result.
-**
-**     SRT_Mem         Store first result in memory cell iParm
-**
-**     SRT_Set         Store results as keys of table iParm.
-**
-**     SRT_Union       Store results as a key in a temporary table iParm
-**
-**     SRT_Except      Remove results from the temporary table iParm.
-**
-**     SRT_Table       Store results in temporary table iParm
-**
-** The table above is incomplete.  Additional eDist value have be added
-** since this comment was written.  See the selectInnerLoop() function for
-** a complete listing of the allowed values of eDest and their meanings.
-**
-** This routine returns the number of errors.  If any errors are
-** encountered, then an appropriate error message is left in
-** pParse->zErrMsg.
-**
-** This routine does NOT free the Select structure passed in.  The
-** calling function needs to do that.
-**
-** The pParent, parentTab, and *pParentAgg fields are filled in if this
-** SELECT is a subquery.  This routine may try to combine this SELECT
-** with its parent to form a single flat query.  In so doing, it might
-** change the parent query from a non-aggregate to an aggregate query.
-** For that reason, the pParentAgg flag is passed as a pointer, so it
-** can be changed.
-**
-** Example 1:   The meaning of the pParent parameter.
-**
-**    SELECT * FROM t1 JOIN (SELECT x, count(*) FROM t2) JOIN t3;
-**    \                      \_______ subquery _______/        /
-**     \                                                      /
-**      \____________________ outer query ___________________/
-**
-** This routine is called for the outer query first.   For that call,
-** pParent will be NULL.  During the processing of the outer query, this 
-** routine is called recursively to handle the subquery.  For the recursive
-** call, pParent will point to the outer query.  Because the subquery is
-** the second element in a three-way join, the parentTab parameter will
-** be 1 (the 2nd value of a 0-indexed array.)
-*/
-int sqlite3Select(
-  Parse *pParse,         /* The parser context */
-  Select *p,             /* The SELECT statement being coded. */
-  int eDest,             /* How to dispose of the results */
-  int iParm,             /* A parameter used by the eDest disposal method */
-  Select *pParent,       /* Another SELECT for which this is a sub-query */
-  int parentTab,         /* Index in pParent->pSrc of this query */
-  int *pParentAgg,       /* True if pParent uses aggregate functions */
-  char *aff              /* If eDest is SRT_Union, the affinity string */
-){
-  int i, j;              /* Loop counters */
-  WhereInfo *pWInfo;     /* Return from sqlite3WhereBegin() */
-  Vdbe *v;               /* The virtual machine under construction */
-  int isAgg;             /* True for select lists like "count(*)" */
-  ExprList *pEList;      /* List of columns to extract. */
-  SrcList *pTabList;     /* List of tables to select from */
-  Expr *pWhere;          /* The WHERE clause.  May be NULL */
-  ExprList *pOrderBy;    /* The ORDER BY clause.  May be NULL */
-  ExprList *pGroupBy;    /* The GROUP BY clause.  May be NULL */
-  Expr *pHaving;         /* The HAVING clause.  May be NULL */
-  int isDistinct;        /* True if the DISTINCT keyword is present */
-  int distinct;          /* Table to use for the distinct set */
-  int rc = 1;            /* Value to return from this function */
-  int addrSortIndex;     /* Address of an OP_OpenEphemeral instruction */
-  AggInfo sAggInfo;      /* Information used by aggregate queries */
-  int iEnd;              /* Address of the end of the query */
-  sqlite3 *db;           /* The database connection */
-
-  db = pParse->db;
-  if( p==0 || db->mallocFailed || pParse->nErr ){
-    return 1;
-  }
-  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
-  memset(&sAggInfo, 0, sizeof(sAggInfo));
-
-  pOrderBy = p->pOrderBy;
-  if( IgnorableOrderby(eDest) ){
-    p->pOrderBy = 0;
-  }
-  if( sqlite3SelectResolve(pParse, p, 0) ){
-    goto select_end;
-  }
-  p->pOrderBy = pOrderBy;
-
-#ifndef SQLITE_OMIT_COMPOUND_SELECT
-  /* If there is are a sequence of queries, do the earlier ones first.
-  */
-  if( p->pPrior ){
-    if( p->pRightmost==0 ){
-      Select *pLoop, *pRight = 0;
-      int cnt = 0;
-      for(pLoop=p; pLoop; pLoop=pLoop->pPrior, cnt++){
-        pLoop->pRightmost = p;
-        pLoop->pNext = pRight;
-        pRight = pLoop;
-      }
-      if( SQLITE_MAX_COMPOUND_SELECT>0 && cnt>SQLITE_MAX_COMPOUND_SELECT ){
-        sqlite3ErrorMsg(pParse, "too many terms in compound SELECT");
-        return 1;
-      }
-    }
-    return multiSelect(pParse, p, eDest, iParm, aff);
-  }
-#endif
-
-  /* Make local copies of the parameters for this query.
-  */
-  pTabList = p->pSrc;
-  pWhere = p->pWhere;
-  pGroupBy = p->pGroupBy;
-  pHaving = p->pHaving;
-  isAgg = p->isAgg;
-  isDistinct = p->isDistinct;
-  pEList = p->pEList;
-  if( pEList==0 ) goto select_end;
-
-  /* 
-  ** Do not even attempt to generate any code if we have already seen
-  ** errors before this routine starts.
-  */
-  if( pParse->nErr>0 ) goto select_end;
-
-  /* If writing to memory or generating a set
-  ** only a single column may be output.
-  */
-#ifndef SQLITE_OMIT_SUBQUERY
-  if( checkForMultiColumnSelectError(pParse, eDest, pEList->nExpr) ){
-    goto select_end;
-  }
-#endif
-
-  /* ORDER BY is ignored for some destinations.
-  */
-  if( IgnorableOrderby(eDest) ){
-    pOrderBy = 0;
-  }
-
-  /* Begin generating code.
-  */
-  v = sqlite3GetVdbe(pParse);
-  if( v==0 ) goto select_end;
-
-  /* Generate code for all sub-queries in the FROM clause
-  */
-#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
-  for(i=0; i<pTabList->nSrc; i++){
-    const char *zSavedAuthContext = 0;
-    int needRestoreContext;
-	SrcList::SrcList_item *pItem = &pTabList->a[i];
-
-    if( pItem->pSelect==0 || pItem->isPopulated ) continue;
-    if( pItem->zName!=0 ){
-      zSavedAuthContext = pParse->zAuthContext;
-      pParse->zAuthContext = pItem->zName;
-      needRestoreContext = 1;
-    }else{
-      needRestoreContext = 0;
-    }
-#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
-    /* Increment Parse.nHeight by the height of the largest expression
-    ** tree refered to by this, the parent select. The child select
-    ** may contain expression trees of at most
-    ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
-    ** more conservative than necessary, but much easier than enforcing
-    ** an exact limit.
-    */
-    pParse->nHeight += sqlite3SelectExprHeight(p);
-#endif
-    sqlite3Select(pParse, pItem->pSelect, SRT_EphemTab, 
-                 pItem->iCursor, p, i, &isAgg, 0);
-    if( db->mallocFailed ){
-      goto select_end;
-    }
-#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
-    pParse->nHeight -= sqlite3SelectExprHeight(p);
-#endif
-    if( needRestoreContext ){
-      pParse->zAuthContext = zSavedAuthContext;
-    }
-    pTabList = p->pSrc;
-    pWhere = p->pWhere;
-    if( !IgnorableOrderby(eDest) ){
-      pOrderBy = p->pOrderBy;
-    }
-    pGroupBy = p->pGroupBy;
-    pHaving = p->pHaving;
-    isDistinct = p->isDistinct;
-  }
-#endif
-
-  /* Check for the special case of a min() or max() function by itself
-  ** in the result set.
-  */
-  if( simpleMinMaxQuery(pParse, p, eDest, iParm) ){
-    rc = 0;
-    goto select_end;
-  }
-
-  /* Check to see if this is a subquery that can be "flattened" into its parent.
-  ** If flattening is a possiblity, do so and return immediately.  
-  */
-#ifndef SQLITE_OMIT_VIEW
-  if( pParent && pParentAgg &&
-      flattenSubquery(db, pParent, parentTab, *pParentAgg, isAgg) ){
-    if( isAgg ) *pParentAgg = 1;
-    goto select_end;
-  }
-#endif
-
-  /* If possible, rewrite the query to use GROUP BY instead of DISTINCT.
-  ** GROUP BY may use an index, DISTINCT never does.
-  */
-  if( p->isDistinct && !p->isAgg && !p->pGroupBy ){
-    p->pGroupBy = sqlite3ExprListDup(db, p->pEList);
-    pGroupBy = p->pGroupBy;
-    p->isDistinct = 0;
-    isDistinct = 0;
-  }
-
-  /* If there is an ORDER BY clause, then this sorting
-  ** index might end up being unused if the data can be 
-  ** extracted in pre-sorted order.  If that is the case, then the
-  ** OP_OpenEphemeral instruction will be changed to an OP_Noop once
-  ** we figure out that the sorting index is not needed.  The addrSortIndex
-  ** variable is used to facilitate that change.
-  */
-  if( pOrderBy ){
-    KeyInfo *pKeyInfo;
-    if( pParse->nErr ){
-      goto select_end;
-    }
-    pKeyInfo = keyInfoFromExprList(pParse, pOrderBy);
-    pOrderBy->iECursor = pParse->nTab++;
-    p->addrOpenEphm[2] = addrSortIndex =
-      sqlite3VdbeOp3(v, OP_OpenEphemeral, pOrderBy->iECursor, pOrderBy->nExpr+2,                     (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
-  }else{
-    addrSortIndex = -1;
-  }
-
-  /* If the output is destined for a temporary table, open that table.
-  */
-  if( eDest==SRT_EphemTab ){
-    sqlite3VdbeAddOp(v, OP_OpenEphemeral, iParm, pEList->nExpr);
-  }
-
-  /* Set the limiter.
-  */
-  iEnd = sqlite3VdbeMakeLabel(v);
-  computeLimitRegisters(pParse, p, iEnd);
-
-  /* Open a virtual index to use for the distinct set.
-  */
-  if( isDistinct ){
-    KeyInfo *pKeyInfo;
-    assert( isAgg || pGroupBy );
-    distinct = pParse->nTab++;
-    pKeyInfo = keyInfoFromExprList(pParse, p->pEList);
-    sqlite3VdbeOp3(v, OP_OpenEphemeral, distinct, 0, 
-                        (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
-  }else{
-    distinct = -1;
-  }
-
-  /* Aggregate and non-aggregate queries are handled differently */
-  if( !isAgg && pGroupBy==0 ){
-    /* This case is for non-aggregate queries
-    ** Begin the database scan
-    */
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pOrderBy);
-    if( pWInfo==0 ) goto select_end;
-
-    /* If sorting index that was created by a prior OP_OpenEphemeral 
-    ** instruction ended up not being needed, then change the OP_OpenEphemeral
-    ** into an OP_Noop.
-    */
-    if( addrSortIndex>=0 && pOrderBy==0 ){
-      sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
-      p->addrOpenEphm[2] = -1;
-    }
-
-    /* Use the standard inner loop
-    */
-    assert(!isDistinct);
-    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, -1, eDest,
-                    iParm, pWInfo->iContinue, pWInfo->iBreak, aff) ){
-       goto select_end;
-    }
-
-    /* End the database scan loop.
-    */
-    sqlite3WhereEnd(pWInfo);
-  }else{
-    /* This is the processing for aggregate queries */
-    NameContext sNC;    /* Name context for processing aggregate information */
-    int iAMem;          /* First Mem address for storing current GROUP BY */
-    int iBMem;          /* First Mem address for previous GROUP BY */
-    int iUseFlag;       /* Mem address holding flag indicating that at least
-                        ** one row of the input to the aggregator has been
-                        ** processed */
-    int iAbortFlag;     /* Mem address which causes query abort if positive */
-    int groupBySort;    /* Rows come from source in GROUP BY order */
-
-
-    /* The following variables hold addresses or labels for parts of the
-    ** virtual machine program we are putting together */
-    int addrOutputRow;      /* Start of subroutine that outputs a result row */
-    int addrSetAbort;       /* Set the abort flag and return */
-    int addrInitializeLoop; /* Start of code that initializes the input loop */
-    int addrTopOfLoop;      /* Top of the input loop */
-    int addrGroupByChange;  /* Code that runs when any GROUP BY term changes */
-    int addrProcessRow;     /* Code to process a single input row */
-    int addrEnd;            /* End of all processing */
-    int addrSortingIdx;     /* The OP_OpenEphemeral for the sorting index */
-    int addrReset;          /* Subroutine for resetting the accumulator */
-
-    addrEnd = sqlite3VdbeMakeLabel(v);
-
-    /* Convert TK_COLUMN nodes into TK_AGG_COLUMN and make entries in
-    ** sAggInfo for all TK_AGG_FUNCTION nodes in expressions of the
-    ** SELECT statement.
-    */
-    memset(&sNC, 0, sizeof(sNC));
-    sNC.pParse = pParse;
-    sNC.pSrcList = pTabList;
-    sNC.pAggInfo = &sAggInfo;
-    sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0;
-    sAggInfo.pGroupBy = pGroupBy;
-    if( sqlite3ExprAnalyzeAggList(&sNC, pEList) ){
-      goto select_end;
-    }
-    if( sqlite3ExprAnalyzeAggList(&sNC, pOrderBy) ){
-      goto select_end;
-    }
-    if( pHaving && sqlite3ExprAnalyzeAggregates(&sNC, pHaving) ){
-      goto select_end;
-    }
-    sAggInfo.nAccumulator = sAggInfo.nColumn;
-    for(i=0; i<sAggInfo.nFunc; i++){
-      if( sqlite3ExprAnalyzeAggList(&sNC, sAggInfo.aFunc[i].pExpr->pList) ){
-        goto select_end;
-      }
-    }
-    if( db->mallocFailed ) goto select_end;
-
-    /* Processing for aggregates with GROUP BY is very different and
-    ** much more complex than aggregates without a GROUP BY.
-    */
-    if( pGroupBy ){
-      KeyInfo *pKeyInfo;  /* Keying information for the group by clause */
-
-      /* Create labels that we will be needing
-      */
-     
-      addrInitializeLoop = sqlite3VdbeMakeLabel(v);
-      addrGroupByChange = sqlite3VdbeMakeLabel(v);
-      addrProcessRow = sqlite3VdbeMakeLabel(v);
-
-      /* If there is a GROUP BY clause we might need a sorting index to
-      ** implement it.  Allocate that sorting index now.  If it turns out
-      ** that we do not need it after all, the OpenEphemeral instruction
-      ** will be converted into a Noop.  
-      */
-      sAggInfo.sortingIdx = pParse->nTab++;
-      pKeyInfo = keyInfoFromExprList(pParse, pGroupBy);
-      addrSortingIdx =
-          sqlite3VdbeOp3(v, OP_OpenEphemeral, sAggInfo.sortingIdx,
-                         sAggInfo.nSortingColumn,
-                         (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
-
-      /* Initialize memory locations used by GROUP BY aggregate processing
-      */
-      iUseFlag = pParse->nMem++;
-      iAbortFlag = pParse->nMem++;
-      iAMem = pParse->nMem;
-      pParse->nMem += pGroupBy->nExpr;
-      iBMem = pParse->nMem;
-      pParse->nMem += pGroupBy->nExpr;
-      sqlite3VdbeAddOp(v, OP_MemInt, 0, iAbortFlag);
-      VdbeComment((v, "# clear abort flag"));
-      sqlite3VdbeAddOp(v, OP_MemInt, 0, iUseFlag);
-      VdbeComment((v, "# indicate accumulator empty"));
-      sqlite3VdbeAddOp(v, OP_Goto, 0, addrInitializeLoop);
-
-      /* Generate a subroutine that outputs a single row of the result
-      ** set.  This subroutine first looks at the iUseFlag.  If iUseFlag
-      ** is less than or equal to zero, the subroutine is a no-op.  If
-      ** the processing calls for the query to abort, this subroutine
-      ** increments the iAbortFlag memory location before returning in
-      ** order to signal the caller to abort.
-      */
-      addrSetAbort = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp(v, OP_MemInt, 1, iAbortFlag);
-      VdbeComment((v, "# set abort flag"));
-      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
-      addrOutputRow = sqlite3VdbeCurrentAddr(v);
-      sqlite3VdbeAddOp(v, OP_IfMemPos, iUseFlag, addrOutputRow+2);
-      VdbeComment((v, "# Groupby result generator entry point"));
-      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
-      finalizeAggFunctions(pParse, &sAggInfo);
-      if( pHaving ){
-        sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, 1);
-      }
-      rc = selectInnerLoop(pParse, p, p->pEList, 0, 0, pOrderBy,
-                           distinct, eDest, iParm, 
-                           addrOutputRow+1, addrSetAbort, aff);
-      if( rc ){
-        goto select_end;
-      }
-      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
-      VdbeComment((v, "# end groupby result generator"));
-
-      /* Generate a subroutine that will reset the group-by accumulator
-      */
-      addrReset = sqlite3VdbeCurrentAddr(v);
-      resetAccumulator(pParse, &sAggInfo);
-      sqlite3VdbeAddOp(v, OP_Return, 0, 0);
-
-      /* Begin a loop that will extract all source rows in GROUP BY order.
-      ** This might involve two separate loops with an OP_Sort in between, or
-      ** it might be a single loop that uses an index to extract information
-      ** in the right order to begin with.
-      */
-      sqlite3VdbeResolveLabel(v, addrInitializeLoop);
-      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
-      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, &pGroupBy);
-      if( pWInfo==0 ) goto select_end;
-      if( pGroupBy==0 ){
-        /* The optimizer is able to deliver rows in group by order so
-        ** we do not have to sort.  The OP_OpenEphemeral table will be
-        ** cancelled later because we still need to use the pKeyInfo
-        */
-        pGroupBy = p->pGroupBy;
-        groupBySort = 0;
-      }else{
-        /* Rows are coming out in undetermined order.  We have to push
-        ** each row into a sorting index, terminate the first loop,
-        ** then loop over the sorting index in order to get the output
-        ** in sorted order
-        */
-        groupBySort = 1;
-        sqlite3ExprCodeExprList(pParse, pGroupBy);
-        sqlite3VdbeAddOp(v, OP_Sequence, sAggInfo.sortingIdx, 0);
-        j = pGroupBy->nExpr+1;
-        for(i=0; i<sAggInfo.nColumn; i++){
-			AggInfo::AggInfo_col *pCol = &sAggInfo.aCol[i];
-          if( pCol->iSorterColumn<j ) continue;
-          sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable);
-          j++;
-        }
-        sqlite3VdbeAddOp(v, OP_MakeRecord, j, 0);
-        sqlite3VdbeAddOp(v, OP_IdxInsert, sAggInfo.sortingIdx, 0);
-        sqlite3WhereEnd(pWInfo);
-        sqlite3VdbeAddOp(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
-        VdbeComment((v, "# GROUP BY sort"));
-        sAggInfo.useSortingIdx = 1;
-      }
-
-      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...
-      ** (b0 is memory location iBMem+0, b1 is iBMem+1, and so forth)
-      ** Then compare the current GROUP BY terms against the GROUP BY terms
-      ** from the previous row currently stored in a0, a1, a2...
-      */
-      addrTopOfLoop = sqlite3VdbeCurrentAddr(v);
-      for(j=0; j<pGroupBy->nExpr; j++){
-        if( groupBySort ){
-          sqlite3VdbeAddOp(v, OP_Column, sAggInfo.sortingIdx, j);
-        }else{
-          sAggInfo.directMode = 1;
-          sqlite3ExprCode(pParse, pGroupBy->a[j].pExpr);
-        }
-        sqlite3VdbeAddOp(v, OP_MemStore, iBMem+j, j<pGroupBy->nExpr-1);
-      }
-      for(j=pGroupBy->nExpr-1; j>=0; j--){
-        if( j<pGroupBy->nExpr-1 ){
-          sqlite3VdbeAddOp(v, OP_MemLoad, iBMem+j, 0);
-        }
-        sqlite3VdbeAddOp(v, OP_MemLoad, iAMem+j, 0);
-        if( j==0 ){
-          sqlite3VdbeAddOp(v, OP_Eq, 0x200, addrProcessRow);
-        }else{
-          sqlite3VdbeAddOp(v, OP_Ne, 0x200, addrGroupByChange);
-        }
-        sqlite3VdbeChangeP3(v, -1, (const char*)pKeyInfo->aColl[j], P3_COLLSEQ);
-      }
-
-      /* Generate code that runs whenever the GROUP BY changes.
-      ** Change in the GROUP BY are detected by the previous code
-      ** block.  If there were no changes, this block is skipped.
-      **
-      ** This code copies current group by terms in b0,b1,b2,...
-      ** over to a0,a1,a2.  It then calls the output subroutine
-      ** and resets the aggregate accumulator registers in preparation
-      ** for the next GROUP BY batch.
-      */
-      sqlite3VdbeResolveLabel(v, addrGroupByChange);
-      for(j=0; j<pGroupBy->nExpr; j++){
-        sqlite3VdbeAddOp(v, OP_MemMove, iAMem+j, iBMem+j);
-      }
-      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
-      VdbeComment((v, "# output one row"));
-      sqlite3VdbeAddOp(v, OP_IfMemPos, iAbortFlag, addrEnd);
-      VdbeComment((v, "# check abort flag"));
-      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrReset);
-      VdbeComment((v, "# reset accumulator"));
-
-      /* Update the aggregate accumulators based on the content of
-      ** the current row
-      */
-      sqlite3VdbeResolveLabel(v, addrProcessRow);
-      updateAccumulator(pParse, &sAggInfo);
-      sqlite3VdbeAddOp(v, OP_MemInt, 1, iUseFlag);
-      VdbeComment((v, "# indicate data in accumulator"));
-
-      /* End of the loop
-      */
-      if( groupBySort ){
-        sqlite3VdbeAddOp(v, OP_Next, sAggInfo.sortingIdx, addrTopOfLoop);
-      }else{
-        sqlite3WhereEnd(pWInfo);
-        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
-      }
-
-      /* Output the final row of result
-      */
-      sqlite3VdbeAddOp(v, OP_Gosub, 0, addrOutputRow);
-      VdbeComment((v, "# output final row"));
-      
-    } /* endif pGroupBy */
-    else {
-      /* This case runs if the aggregate has no GROUP BY clause.  The
-      ** processing is much simpler since there is only a single row
-      ** of output.
-      */
-      resetAccumulator(pParse, &sAggInfo);
-      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0);
-      if( pWInfo==0 ) goto select_end;
-      updateAccumulator(pParse, &sAggInfo);
-      sqlite3WhereEnd(pWInfo);
-      finalizeAggFunctions(pParse, &sAggInfo);
-      pOrderBy = 0;
-      if( pHaving ){
-        sqlite3ExprIfFalse(pParse, pHaving, addrEnd, 1);
-      }
-      selectInnerLoop(pParse, p, p->pEList, 0, 0, 0, -1, 
-                      eDest, iParm, addrEnd, addrEnd, aff);
-    }
-    sqlite3VdbeResolveLabel(v, addrEnd);
-    
-  } /* endif aggregate query */
-
-  /* If there is an ORDER BY clause, then we need to sort the results
-  ** and send them to the callback one by one.
-  */
-  if( pOrderBy ){
-    generateSortTail(pParse, p, v, pEList->nExpr, eDest, iParm);
-  }
-
-#ifndef SQLITE_OMIT_SUBQUERY
-  /* If this was a subquery, we have now converted the subquery into a
-  ** temporary table.  So set the SrcList_item.isPopulated flag to prevent
-  ** this subquery from being evaluated again and to force the use of
-  ** the temporary table.
-  */
-  if( pParent ){
-    assert( pParent->pSrc->nSrc>parentTab );
-    assert( pParent->pSrc->a[parentTab].pSelect==p );
-    pParent->pSrc->a[parentTab].isPopulated = 1;
-  }
-#endif
-
-  /* Jump here to skip this query
-  */
-  sqlite3VdbeResolveLabel(v, iEnd);
-
-  /* The SELECT was successfully coded.   Set the return code to 0
-  ** to indicate no errors.
-  */
-  rc = 0;
-
-  /* Control jumps to here if an error is encountered above, or upon
-  ** successful coding of the SELECT.
-  */
-select_end:
-
-  /* Identify column names if we will be using them in a callback.  This
-  ** step is skipped if the output is going to some other destination.
-  */
-  if( rc==SQLITE_OK && eDest==SRT_Callback ){
-    generateColumnNames(pParse, pTabList, pEList);
-  }
-
-  sqlite3_free(sAggInfo.aCol);
-  sqlite3_free(sAggInfo.aFunc);
-  return rc;
-}
-
-#if defined(SQLITE_DEBUG)
-/*
-*******************************************************************************
-** The following code is used for testing and debugging only.  The code
-** that follows does not appear in normal builds.
-**
-** These routines are used to print out the content of all or part of a 
-** parse structures such as Select or Expr.  Such printouts are useful
-** for helping to understand what is happening inside the code generator
-** during the execution of complex SELECT statements.
-**
-** These routine are not called anywhere from within the normal
-** code base.  Then are intended to be called from within the debugger
-** or from temporary "printf" statements inserted for debugging.
-*/
-void sqlite3PrintExpr(Expr *p){
-  if( p->token.z && p->token.n>0 ){
-    sqlite3DebugPrintf("(%.*s", p->token.n, p->token.z);
-  }else{
-    sqlite3DebugPrintf("(%d", p->op);
-  }
-  if( p->pLeft ){
-    sqlite3DebugPrintf(" ");
-    sqlite3PrintExpr(p->pLeft);
-  }
-  if( p->pRight ){
-    sqlite3DebugPrintf(" ");
-    sqlite3PrintExpr(p->pRight);
-  }
-  sqlite3DebugPrintf(")");
-}
-void sqlite3PrintExprList(ExprList *pList){
-  int i;
-  for(i=0; i<pList->nExpr; i++){
-    sqlite3PrintExpr(pList->a[i].pExpr);
-    if( i<pList->nExpr-1 ){
-      sqlite3DebugPrintf(", ");
-    }
-  }
-}
-void sqlite3PrintSelect(Select *p, int indent){
-  sqlite3DebugPrintf("%*sSELECT(%p) ", indent, "", p);
-  sqlite3PrintExprList(p->pEList);
-  sqlite3DebugPrintf("\n");
-  if( p->pSrc ){
-    char *zPrefix;
-    int i;
-    zPrefix = "FROM";
-    for(i=0; i<p->pSrc->nSrc; i++){
-      struct SrcList_item *pItem = &p->pSrc->a[i];
-      sqlite3DebugPrintf("%*s ", indent+6, zPrefix);
-      zPrefix = "";
-      if( pItem->pSelect ){
-        sqlite3DebugPrintf("(\n");
-        sqlite3PrintSelect(pItem->pSelect, indent+10);
-        sqlite3DebugPrintf("%*s)", indent+8, "");
-      }else if( pItem->zName ){
-        sqlite3DebugPrintf("%s", pItem->zName);
-      }
-      if( pItem->pTab ){
-        sqlite3DebugPrintf("(table: %s)", pItem->pTab->zName);
-      }
-      if( pItem->zAlias ){
-        sqlite3DebugPrintf(" AS %s", pItem->zAlias);
-      }
-      if( i<p->pSrc->nSrc-1 ){
-        sqlite3DebugPrintf(",");
-      }
-      sqlite3DebugPrintf("\n");
-    }
-  }
-  if( p->pWhere ){
-    sqlite3DebugPrintf("%*s WHERE ", indent, "");
-    sqlite3PrintExpr(p->pWhere);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pGroupBy ){
-    sqlite3DebugPrintf("%*s GROUP BY ", indent, "");
-    sqlite3PrintExprList(p->pGroupBy);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pHaving ){
-    sqlite3DebugPrintf("%*s HAVING ", indent, "");
-    sqlite3PrintExpr(p->pHaving);
-    sqlite3DebugPrintf("\n");
-  }
-  if( p->pOrderBy ){
-    sqlite3DebugPrintf("%*s ORDER BY ", indent, "");
-    sqlite3PrintExprList(p->pOrderBy);
-    sqlite3DebugPrintf("\n");
-  }
-}
-/* End of the structure debug printing code
-*****************************************************************************/
-#endif /* defined(SQLITE_TEST) || defined(SQLITE_DEBUG) */