Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdenetwork@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 2628 insertions, 0 deletions

diff --git a/kopete/plugins/statistics/sqlite/select.c b/kopete/plugins/statistics/sqlite/select.c
new file mode 100644
index 00000000..8bee7897
--- /dev/null
+++ b/kopete/plugins/statistics/sqlite/select.c
@@ -0,0 +1,2628 @@
+/*
+** 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.
+**
+** $Id$
+*/
+#include "sqliteInt.h"
+
+
+/*
+** Allocate a new Select structure and return a pointer to that
+** structure.
+*/
+Select *sqlite3SelectNew(
+  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 */
+  int nLimit,           /* LIMIT value.  -1 means not used */
+  int nOffset           /* OFFSET value.  0 means no offset */
+){
+  Select *pNew;
+  pNew = sqliteMalloc( sizeof(*pNew) );
+  if( pNew==0 ){
+    sqlite3ExprListDelete(pEList);
+    sqlite3SrcListDelete(pSrc);
+    sqlite3ExprDelete(pWhere);
+    sqlite3ExprListDelete(pGroupBy);
+    sqlite3ExprDelete(pHaving);
+    sqlite3ExprListDelete(pOrderBy);
+  }else{
+    if( pEList==0 ){
+      pEList = sqlite3ExprListAppend(0, sqlite3Expr(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;
+    pNew->nLimit = nLimit;
+    pNew->nOffset = nOffset;
+    pNew->iLimit = -1;
+    pNew->iOffset = -1;
+  }
+  return pNew;
+}
+
+/*
+** 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_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;
+    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 },
+  };
+  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(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 = z;
+  p->n = strlen(z);
+  p->dyn = 0;
+}
+
+
+/*
+** 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(
+  const char *zCol,        /* Name of the column */
+  const Table *pTab1,      /* First table */
+  const Table *pTab2,      /* Second table */
+  Expr **ppExpr            /* Add the equality term to this expression */
+){
+  Token dummy;
+  Expr *pE1a, *pE1b, *pE1c;
+  Expr *pE2a, *pE2b, *pE2c;
+  Expr *pE;
+
+  setToken(&dummy, zCol);
+  pE1a = sqlite3Expr(TK_ID, 0, 0, &dummy);
+  pE2a = sqlite3Expr(TK_ID, 0, 0, &dummy);
+  setToken(&dummy, pTab1->zName);
+  pE1b = sqlite3Expr(TK_ID, 0, 0, &dummy);
+  setToken(&dummy, pTab2->zName);
+  pE2b = sqlite3Expr(TK_ID, 0, 0, &dummy);
+  pE1c = sqlite3Expr(TK_DOT, pE1b, pE1a, 0);
+  pE2c = sqlite3Expr(TK_DOT, pE2b, pE2a, 0);
+  pE = sqlite3Expr(TK_EQ, pE1c, pE2c, 0);
+  ExprSetProperty(pE, EP_FromJoin);
+  *ppExpr = sqlite3ExprAnd(*ppExpr, pE);
+}
+
+/*
+** Set the EP_FromJoin property on all terms of the given 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.
+*/
+static void setJoinExpr(Expr *p){
+  while( p ){
+    ExprSetProperty(p, EP_FromJoin);
+    setJoinExpr(p->pLeft);
+    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 */
+  struct SrcList_item *pLeft;     /* Left table being joined */
+  struct 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( pLeft->jointype & JT_NATURAL ){
+      if( pLeft->pOn || pLeft->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(zName, pLeftTab, pRightTab, &p->pWhere);
+        }
+      }
+    }
+
+    /* Disallow both ON and USING clauses in the same join
+    */
+    if( pLeft->pOn && pLeft->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( pLeft->pOn ){
+      setJoinExpr(pLeft->pOn);
+      p->pWhere = sqlite3ExprAnd(p->pWhere, pLeft->pOn);
+      pLeft->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( pLeft->pUsing ){
+      IdList *pList = pLeft->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(zName, pLeftTab, pRightTab, &p->pWhere);
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Delete the given Select structure and all of its substructures.
+*/
+void sqlite3SelectDelete(Select *p){
+  if( p==0 ) return;
+  sqlite3ExprListDelete(p->pEList);
+  sqlite3SrcListDelete(p->pSrc);
+  sqlite3ExprDelete(p->pWhere);
+  sqlite3ExprListDelete(p->pGroupBy);
+  sqlite3ExprDelete(p->pHaving);
+  sqlite3ExprListDelete(p->pOrderBy);
+  sqlite3SelectDelete(p->pPrior);
+  sqliteFree(p->zSelect);
+  sqliteFree(p);
+}
+
+/*
+** Delete the aggregate information from the parse structure.
+*/
+static void sqliteAggregateInfoReset(Parse *pParse){
+  sqliteFree(pParse->aAgg);
+  pParse->aAgg = 0;
+  pParse->nAgg = 0;
+  pParse->useAgg = 0;
+}
+
+/*
+** Insert code into "v" that will push the record on the top of the
+** stack into the sorter.
+*/
+static void pushOntoSorter(Parse *pParse, Vdbe *v, ExprList *pOrderBy){
+  int i;
+  for(i=0; i<pOrderBy->nExpr; i++){
+    sqlite3ExprCode(pParse, pOrderBy->a[i].pExpr);
+  }
+  sqlite3VdbeAddOp(v, OP_MakeRecord, pOrderBy->nExpr, 0);
+  sqlite3VdbeAddOp(v, OP_SortPut, 0, 0);
+}
+
+/*
+** Add code to implement the OFFSET and LIMIT
+*/
+static void codeLimiter(
+  Vdbe *v,          /* Generate code into this VM */
+  Select *p,        /* The SELECT statement being coded */
+  int iContinue,    /* Jump here to skip the current record */
+  int iBreak,       /* Jump here to end the loop */
+  int nPop          /* Number of times to pop stack when jumping */
+){
+  if( p->iOffset>=0 ){
+    int addr = sqlite3VdbeCurrentAddr(v) + 2;
+    if( nPop>0 ) addr++;
+    sqlite3VdbeAddOp(v, OP_MemIncr, p->iOffset, addr);
+    if( nPop>0 ){
+      sqlite3VdbeAddOp(v, OP_Pop, nPop, 0);
+    }
+    sqlite3VdbeAddOp(v, OP_Goto, 0, iContinue);
+    VdbeComment((v, "# skip OFFSET records"));
+  }
+  if( p->iLimit>=0 ){
+    sqlite3VdbeAddOp(v, OP_MemIncr, p->iLimit, iBreak);
+    VdbeComment((v, "# exit when LIMIT reached"));
+  }
+}
+
+/*
+** 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 && pEList->nExpr>0;
+  if( pOrderBy==0 && !hasDistinct ){
+    codeLimiter(v, p, iContinue, iBreak, 0);
+  }
+
+  /* Pull the requested columns.
+  */
+  if( nColumn>0 ){
+    for(i=0; i<nColumn; i++){
+      sqlite3VdbeAddOp(v, OP_Column, srcTab, i);
+    }
+  }else{
+    nColumn = pEList->nExpr;
+    for(i=0; i<pEList->nExpr; i++){
+      sqlite3ExprCode(pParse, pEList->a[i].pExpr);
+    }
+  }
+
+  /* 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 ){
+#if NULL_ALWAYS_DISTINCT
+    sqlite3VdbeAddOp(v, OP_IsNull, -pEList->nExpr, sqlite3VdbeCurrentAddr(v)+7);
+#endif
+    /* Deliberately leave the affinity string off of the following
+    ** OP_MakeRecord */
+    sqlite3VdbeAddOp(v, OP_MakeRecord, pEList->nExpr * -1, 0);
+    sqlite3VdbeAddOp(v, OP_Distinct, distinct, sqlite3VdbeCurrentAddr(v)+3);
+    sqlite3VdbeAddOp(v, OP_Pop, pEList->nExpr+1, 0);
+    sqlite3VdbeAddOp(v, OP_Goto, 0, iContinue);
+    VdbeComment((v, "# skip indistinct records"));
+    sqlite3VdbeAddOp(v, OP_String8, 0, 0);
+    sqlite3VdbeAddOp(v, OP_PutStrKey, distinct, 0);
+    if( pOrderBy==0 ){
+      codeLimiter(v, p, iContinue, iBreak, nColumn);
+    }
+  }
+
+  switch( eDest ){
+    /* In this mode, write each query result to the key of the temporary
+    ** table iParm.
+    */
+    case SRT_Union: {
+      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, NULL_ALWAYS_DISTINCT);
+      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
+      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
+      sqlite3VdbeAddOp(v, OP_PutStrKey, iParm, 0);
+      break;
+    }
+
+    /* Store the result as data using a unique key.
+    */
+    case SRT_Table:
+    case SRT_TempTable: {
+      sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
+      if( pOrderBy ){
+        pushOntoSorter(pParse, v, pOrderBy);
+      }else{
+        sqlite3VdbeAddOp(v, OP_NewRecno, iParm, 0);
+        sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
+        sqlite3VdbeAddOp(v, OP_PutIntKey, 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, NULL_ALWAYS_DISTINCT);
+      sqlite3VdbeChangeP3(v, -1, aff, P3_STATIC);
+      sqlite3VdbeAddOp(v, OP_NotFound, iParm, addr+3);
+      sqlite3VdbeAddOp(v, OP_Delete, iParm, 0);
+      break;
+    }
+
+    /* 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);
+      if( pOrderBy ){
+        pushOntoSorter(pParse, v, pOrderBy);
+      }else{
+        char aff = (iParm>>16)&0xFF;
+        aff = sqlite3CompareAffinity(pEList->a[0].pExpr, aff);
+        sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &aff, 1);
+        sqlite3VdbeAddOp(v, OP_String8, 0, 0);
+        sqlite3VdbeAddOp(v, OP_PutStrKey, (iParm&0x0000FFFF), 0);
+      }
+      sqlite3VdbeChangeP2(v, addr2, sqlite3VdbeCurrentAddr(v));
+      break;
+    }
+
+    /* If this is a scalar select that is part of an expression, then
+    ** store the results in the appropriate memory cell and break out
+    ** of the scan loop.
+    */
+    case SRT_Mem: {
+      assert( nColumn==1 );
+      if( pOrderBy ){
+        pushOntoSorter(pParse, v, pOrderBy);
+      }else{
+        sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
+        sqlite3VdbeAddOp(v, OP_Goto, 0, iBreak);
+      }
+      break;
+    }
+
+    /* Send the data to the callback function.
+    */
+    case SRT_Callback:
+    case SRT_Sorter: {
+      if( pOrderBy ){
+        sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
+        pushOntoSorter(pParse, v, pOrderBy);
+      }else{
+        assert( eDest==SRT_Callback );
+        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
+      }
+      break;
+    }
+
+    /* Invoke a subroutine to handle the results.  The subroutine itself
+    ** is responsible for popping the results off of the stack.
+    */
+    case SRT_Subroutine: {
+      if( pOrderBy ){
+        sqlite3VdbeAddOp(v, OP_MakeRecord, nColumn, 0);
+        pushOntoSorter(pParse, v, pOrderBy);
+      }else{
+        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
+      }
+      break;
+    }
+
+    /* 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;
+    }
+  }
+  return 0;
+}
+
+/*
+** 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,   /* The 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 end1 = sqlite3VdbeMakeLabel(v);
+  int end2 = sqlite3VdbeMakeLabel(v);
+  int addr;
+  KeyInfo *pInfo;
+  ExprList *pOrderBy;
+  int nCol, i;
+  sqlite3 *db = pParse->db;
+
+  if( eDest==SRT_Sorter ) return;
+  pOrderBy = p->pOrderBy;
+  nCol = pOrderBy->nExpr;
+  pInfo = sqliteMalloc( sizeof(*pInfo) + nCol*(sizeof(CollSeq*)+1) );
+  if( pInfo==0 ) return;
+  pInfo->aSortOrder = (char*)&pInfo->aColl[nCol];
+  pInfo->nField = nCol;
+  for(i=0; i<nCol; i++){
+    /* If a collation sequence was specified explicity, then it
+    ** is stored in pOrderBy->a[i].zName. Otherwise, use the default
+    ** collation type for the expression.
+    */
+    pInfo->aColl[i] = sqlite3ExprCollSeq(pParse, pOrderBy->a[i].pExpr);
+    if( !pInfo->aColl[i] ){
+      pInfo->aColl[i] = db->pDfltColl;
+    }
+    pInfo->aSortOrder[i] = pOrderBy->a[i].sortOrder;
+  }
+  sqlite3VdbeOp3(v, OP_Sort, 0, 0, (char*)pInfo, P3_KEYINFO_HANDOFF);
+  addr = sqlite3VdbeAddOp(v, OP_SortNext, 0, end1);
+  codeLimiter(v, p, addr, end2, 1);
+  switch( eDest ){
+    case SRT_Table:
+    case SRT_TempTable: {
+      sqlite3VdbeAddOp(v, OP_NewRecno, iParm, 0);
+      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
+      sqlite3VdbeAddOp(v, OP_PutIntKey, iParm, 0);
+      break;
+    }
+    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, "n", P3_STATIC);
+      sqlite3VdbeAddOp(v, OP_String8, 0, 0);
+      sqlite3VdbeAddOp(v, OP_PutStrKey, (iParm&0x0000FFFF), 0);
+      break;
+    }
+    case SRT_Mem: {
+      assert( nColumn==1 );
+      sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
+      sqlite3VdbeAddOp(v, OP_Goto, 0, end1);
+      break;
+    }
+    case SRT_Callback:
+    case SRT_Subroutine: {
+      int i;
+      sqlite3VdbeAddOp(v, OP_Integer, p->pEList->nExpr, 0);
+      sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
+      for(i=0; i<nColumn; i++){
+        sqlite3VdbeAddOp(v, OP_Column, -1-i, i);
+      }
+      if( eDest==SRT_Callback ){
+        sqlite3VdbeAddOp(v, OP_Callback, nColumn, 0);
+      }else{
+        sqlite3VdbeAddOp(v, OP_Gosub, 0, iParm);
+      }
+      sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
+      break;
+    }
+    default: {
+      /* Do nothing */
+      break;
+    }
+  }
+  sqlite3VdbeAddOp(v, OP_Goto, 0, addr);
+  sqlite3VdbeResolveLabel(v, end2);
+  sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
+  sqlite3VdbeResolveLabel(v, end1);
+  sqlite3VdbeAddOp(v, OP_SortReset, 0, 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.
+**
+** If 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 an expression is either TEXT, NUMERIC or ANY.
+** The declaration type for a ROWID field is INTEGER.
+*/
+static const char *columnType(Parse *pParse, SrcList *pTabList, Expr *pExpr){
+  char const *zType;
+  int j;
+  if( pExpr==0 || pTabList==0 ) return 0;
+
+  switch( pExpr->op ){
+    case TK_COLUMN: {
+      Table *pTab;
+      int iCol = pExpr->iColumn;
+      for(j=0; j<pTabList->nSrc && pTabList->a[j].iCursor!=pExpr->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 ){
+        zType = "INTEGER";
+      }else{
+        zType = pTab->aCol[iCol].zType;
+      }
+      break;
+    }
+    case TK_AS:
+      zType = columnType(pParse, pTabList, pExpr->pLeft); 
+      break;
+    case TK_SELECT: {
+      Select *pS = pExpr->pSelect;
+      zType = columnType(pParse, pS->pSrc, pS->pEList->a[0].pExpr); 
+      break;
+    }
+    default:
+      zType = 0;
+  }
+  
+  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;
+  for(i=0; i<pEList->nExpr; i++){
+    Expr *p = pEList->a[i].pExpr;
+    const char *zType = columnType(pParse, pTabList, p);
+    if( zType==0 ) continue;
+    /* The vdbe must make it's own copy of the column-type, in case the 
+    ** schema is reset before this virtual machine is deleted.
+    */
+    sqlite3VdbeSetColName(v, i+pEList->nExpr, zType, strlen(zType));
+  }
+}
+
+/*
+** 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;
+
+  /* If this is an EXPLAIN, skip this step */
+  if( pParse->explain ){
+    return;
+  }
+
+  assert( v!=0 );
+  if( pParse->colNamesSet || v==0 || sqlite3_malloc_failed ) 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, 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, 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, 0);
+        sqlite3VdbeSetColName(v, i, zName, P3_DYNAMIC);
+      }else{
+        sqlite3VdbeSetColName(v, i, zCol, 0);
+      }
+    }else if( p->span.z && p->span.z[0] ){
+      sqlite3VdbeSetColName(v, i, p->span.z, p->span.n);
+      /* sqlite3VdbeCompressSpace(v, addr); */
+    }else{
+      char zName[30];
+      assert( p->op!=TK_COLUMN || pTabList==0 );
+      sprintf(zName, "column%d", i+1);
+      sqlite3VdbeSetColName(v, i, zName, 0);
+    }
+  }
+  generateColumnTypes(pParse, pTabList, pEList);
+}
+
+/*
+** 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;
+}
+
+/*
+** Forward declaration
+*/
+static int fillInColumnList(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;
+
+  if( fillInColumnList(pParse, pSelect) ){
+    return 0;
+  }
+  pTab = sqliteMalloc( sizeof(Table) );
+  if( pTab==0 ){
+    return 0;
+  }
+  pTab->zName = zTabName ? sqliteStrDup(zTabName) : 0;
+  pEList = pSelect->pEList;
+  pTab->nCol = pEList->nExpr;
+  assert( pTab->nCol>0 );
+  pTab->aCol = aCol = sqliteMalloc( sizeof(pTab->aCol[0])*pTab->nCol );
+  for(i=0, pCol=aCol; i<pTab->nCol; i++, pCol++){
+    Expr *pR;
+    char *zType;
+    char *zName;
+    Expr *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 ){
+      zName = sqliteStrDup(zName);
+    }else if( p->op==TK_DOT 
+               && (pR=p->pRight)!=0 && pR->token.z && pR->token.z[0] ){
+      int cnt;
+      zName = sqlite3MPrintf("%T", &pR->token);
+      for(j=cnt=0; j<i; j++){
+        if( sqlite3StrICmp(aCol[j].zName, zName)==0 ){
+          sqliteFree(zName);
+          zName = sqlite3MPrintf("%T_%d", &pR->token, ++cnt);
+          j = -1;
+        }
+      }
+    }else if( p->span.z && p->span.z[0] ){
+      zName = sqlite3MPrintf("%T", &p->span);
+    }else{
+      zName = sqlite3MPrintf("column%d", i+1);
+    }
+    sqlite3Dequote(zName);
+    pCol->zName = zName;
+
+    zType = sqliteStrDup(columnType(pParse, pSelect->pSrc ,p));
+    pCol->zType = zType;
+    pCol->affinity = SQLITE_AFF_NUMERIC;
+    if( zType ){
+      pCol->affinity = sqlite3AffinityType(zType, strlen(zType));
+    }
+    pCol->pColl = sqlite3ExprCollSeq(pParse, p);
+    if( !pCol->pColl ){
+      pCol->pColl = pParse->db->pDfltColl;
+    }
+  }
+  pTab->iPKey = -1;
+  return pTab;
+}
+
+/*
+** For the given SELECT statement, do three things.
+**
+**    (1)  Fill in the pTabList->a[].pTab fields in the SrcList that 
+**         defines the set of tables that should be scanned.  For views,
+**         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.
+**
+**    (2)  Add terms to the WHERE clause to accomodate the NATURAL keyword
+**         on joins and the ON and USING clause of joins.
+**
+**    (3)  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 fillInColumnList(Parse *pParse, Select *p){
+  int i, j, k, rc;
+  SrcList *pTabList;
+  ExprList *pEList;
+  Table *pTab;
+  struct SrcList_item *pFrom;
+
+  if( p==0 || p->pSrc==0 ) return 1;
+  pTabList = p->pSrc;
+  pEList = p->pEList;
+
+  /* Look up every table in the table list.
+  */
+  for(i=0, pFrom=pTabList->a; i<pTabList->nSrc; i++, pFrom++){
+    if( pFrom->pTab ){
+      /* This routine has run before!  No need to continue */
+      return 0;
+    }
+    if( pFrom->zName==0 ){
+      /* A sub-query in the FROM clause of a SELECT */
+      assert( pFrom->pSelect!=0 );
+      if( pFrom->zAlias==0 ){
+        pFrom->zAlias =
+          sqlite3MPrintf("sqlite_subquery_%p_", (void*)pFrom->pSelect);
+      }
+      pFrom->pTab = pTab = 
+        sqlite3ResultSetOfSelect(pParse, pFrom->zAlias, pFrom->pSelect);
+      if( pTab==0 ){
+        return 1;
+      }
+      /* The isTransient flag indicates that the Table structure has been
+      ** dynamically allocated and may be freed at any time.  In other words,
+      ** pTab is not pointing to a persistent table structure that defines
+      ** part of the schema. */
+      pTab->isTransient = 1;
+    }else{
+      /* An ordinary table or view name in the FROM clause */
+      pFrom->pTab = pTab = 
+        sqlite3LocateTable(pParse,pFrom->zName,pFrom->zDatabase);
+      if( pTab==0 ){
+        return 1;
+      }
+      if( pTab->pSelect ){
+        /* We reach here if the named table is a really a view */
+        if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+          return 1;
+        }
+        /* If 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(pTab->pSelect);
+        }
+      }
+    }
+  }
+
+  /* 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.
+    */
+    struct ExprList_item *a = pEList->a;
+    ExprList *pNew = 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(pNew, a[k].pExpr, 0);
+        pNew->a[pNew->nExpr-1].zName = a[k].zName;
+        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(&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, *pLeft, *pRight;
+            char *zName = pTab->aCol[j].zName;
+
+            if( i>0 ){
+              struct SrcList_item *pLeft = &pTabList->a[i-1];
+              if( (pLeft->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->pUsing, zName)>=0 ){
+                /* In a join with a USING clause, omit columns in the
+                ** using clause from the table on the right. */
+                continue;
+              }
+            }
+            pRight = sqlite3Expr(TK_ID, 0, 0, 0);
+            if( pRight==0 ) break;
+            setToken(&pRight->token, zName);
+            if( zTabName && pTabList->nSrc>1 ){
+              pLeft = sqlite3Expr(TK_ID, 0, 0, 0);
+              pExpr = sqlite3Expr(TK_DOT, pLeft, pRight, 0);
+              if( pExpr==0 ) break;
+              setToken(&pLeft->token, zTabName);
+              setToken(&pExpr->span, sqlite3MPrintf("%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;
+            }
+            pNew = sqlite3ExprListAppend(pNew, pExpr, 0);
+          }
+        }
+        if( !tableSeen ){
+          if( zTName ){
+            sqlite3ErrorMsg(pParse, "no such table: %s", zTName);
+          }else{
+            sqlite3ErrorMsg(pParse, "no tables specified");
+          }
+          rc = 1;
+        }
+        sqliteFree(zTName);
+      }
+    }
+    sqlite3ExprListDelete(pEList);
+    p->pEList = pNew;
+  }
+  return rc;
+}
+
+/*
+** This routine recursively unlinks the Select.pSrc.a[].pTab pointers
+** in a select structure.  It just sets the pointers to NULL.  This
+** routine is recursive in the sense that if the Select.pSrc.a[].pSelect
+** pointer is not NULL, this routine is called recursively on that pointer.
+**
+** This routine is called on the Select structure that defines a
+** VIEW in order to undo any bindings to tables.  This is necessary
+** because those tables might be DROPed by a subsequent SQL command.
+** If the bindings are not removed, then the Select.pSrc->a[].pTab field
+** will be left pointing to a deallocated Table structure after the
+** DROP and a coredump will occur the next time the VIEW is used.
+*/
+void sqlite3SelectUnbind(Select *p){
+  int i;
+  SrcList *pSrc = p->pSrc;
+  struct SrcList_item *pItem;
+  Table *pTab;
+  if( p==0 ) return;
+  for(i=0, pItem=pSrc->a; i<pSrc->nSrc; i++, pItem++){
+    if( (pTab = pItem->pTab)!=0 ){
+      if( pTab->isTransient ){
+        sqlite3DeleteTable(0, pTab);
+      }
+      pItem->pTab = 0;
+      if( pItem->pSelect ){
+        sqlite3SelectUnbind(pItem->pSelect);
+      }
+    }
+  }
+}
+
+/*
+** This routine associates entries in an ORDER BY expression list with
+** columns in a result.  For each ORDER BY expression, the opcode of
+** the top-level node is changed to TK_COLUMN and the iColumn value of
+** the top-level node is filled in with column number and the iTable
+** value of the top-level node is filled with iTable parameter.
+**
+** If there are prior SELECT clauses, they are processed first.  A match
+** in an earlier SELECT takes precedence over a later SELECT.
+**
+** Any entry that does not match is flagged as an error.  The number
+** of errors is returned.
+*/
+static int matchOrderbyToColumn(
+  Parse *pParse,          /* A place to leave error messages */
+  Select *pSelect,        /* Match to result columns of this SELECT */
+  ExprList *pOrderBy,     /* The ORDER BY values to match against columns */
+  int iTable,             /* Insert this value in iTable */
+  int mustComplete        /* If TRUE all ORDER BYs must match */
+){
+  int nErr = 0;
+  int i, j;
+  ExprList *pEList;
+
+  if( pSelect==0 || pOrderBy==0 ) return 1;
+  if( mustComplete ){
+    for(i=0; i<pOrderBy->nExpr; i++){ pOrderBy->a[i].done = 0; }
+  }
+  if( fillInColumnList(pParse, pSelect) ){
+    return 1;
+  }
+  if( pSelect->pPrior ){
+    if( matchOrderbyToColumn(pParse, pSelect->pPrior, pOrderBy, iTable, 0) ){
+      return 1;
+    }
+  }
+  pEList = pSelect->pEList;
+  for(i=0; i<pOrderBy->nExpr; i++){
+    Expr *pE = pOrderBy->a[i].pExpr;
+    int iCol = -1;
+    if( pOrderBy->a[i].done ) continue;
+    if( sqlite3ExprIsInteger(pE, &iCol) ){
+      if( iCol<=0 || iCol>pEList->nExpr ){
+        sqlite3ErrorMsg(pParse,
+          "ORDER BY position %d should be between 1 and %d",
+          iCol, pEList->nExpr);
+        nErr++;
+        break;
+      }
+      if( !mustComplete ) continue;
+      iCol--;
+    }
+    for(j=0; iCol<0 && j<pEList->nExpr; j++){
+      if( pEList->a[j].zName && (pE->op==TK_ID || pE->op==TK_STRING) ){
+        char *zName, *zLabel;
+        zName = pEList->a[j].zName;
+        zLabel = sqlite3NameFromToken(&pE->token);
+        assert( zLabel!=0 );
+        if( sqlite3StrICmp(zName, zLabel)==0 ){ 
+          iCol = j;
+        }
+        sqliteFree(zLabel);
+      }
+      if( iCol<0 && sqlite3ExprCompare(pE, pEList->a[j].pExpr) ){
+        iCol = j;
+      }
+    }
+    if( iCol>=0 ){
+      pE->op = TK_COLUMN;
+      pE->iColumn = iCol;
+      pE->iTable = iTable;
+      pOrderBy->a[i].done = 1;
+    }
+    if( iCol<0 && mustComplete ){
+      sqlite3ErrorMsg(pParse,
+        "ORDER BY term number %d does not match any result column", i+1);
+      nErr++;
+      break;
+    }
+  }
+  return nErr;  
+}
+
+/*
+** 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
+** nLimit and nOffset fields.  nLimit and nOffset hold the integers
+** that appear in the original SQL statement after the LIMIT and OFFSET
+** keywords.  Or that hold -1 and 0 if those keywords are omitted.
+** iLimit and iOffset are the integer memory register numbers for
+** counters used to compute the limit and offset.  If there is no
+** limit and/or offset, then iLimit and iOffset are negative.
+**
+** This routine changes the values if iLimit and iOffset only if
+** a limit or offset is defined by nLimit and nOffset.  iLimit and
+** iOffset should have been preset to appropriate default values
+** (usually but not always -1) prior to calling this routine.
+** Only if nLimit>=0 or nOffset>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){
+  /* 
+  ** If the comparison is p->nLimit>0 then "LIMIT 0" shows
+  ** all rows.  It is the same as no limit. If the comparision is
+  ** p->nLimit>=0 then "LIMIT 0" show no rows at all.
+  ** "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->nLimit>=0 ){
+    int iMem = pParse->nMem++;
+    Vdbe *v = sqlite3GetVdbe(pParse);
+    if( v==0 ) return;
+    sqlite3VdbeAddOp(v, OP_Integer, -p->nLimit, 0);
+    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 1);
+    VdbeComment((v, "# LIMIT counter"));
+    p->iLimit = iMem;
+  }
+  if( p->nOffset>0 ){
+    int iMem = pParse->nMem++;
+    Vdbe *v = sqlite3GetVdbe(pParse);
+    if( v==0 ) return;
+    sqlite3VdbeAddOp(v, OP_Integer, -p->nOffset, 0);
+    sqlite3VdbeAddOp(v, OP_MemStore, iMem, 1);
+    VdbeComment((v, "# OFFSET counter"));
+    p->iOffset = iMem;
+  }
+}
+
+/*
+** Generate VDBE instructions that will open a transient table that
+** will be used for an index or to store keyed results for a compound
+** select.  In other words, open a transient table that needs a
+** KeyInfo structure.  The number of columns in the KeyInfo is determined
+** by the result set of the SELECT statement in the second argument.
+**
+** Specifically, this routine is called to open an index table for
+** DISTINCT, UNION, INTERSECT and EXCEPT select statements (but not 
+** UNION ALL).
+**
+** Make the new table a KeyAsData table if keyAsData is true.
+**
+** The value returned is the address of the OP_OpenTemp instruction.
+*/
+static int openTempIndex(Parse *pParse, Select *p, int iTab, int keyAsData){
+  KeyInfo *pKeyInfo;
+  int nColumn;
+  sqlite3 *db = pParse->db;
+  int i;
+  Vdbe *v = pParse->pVdbe;
+  int addr;
+
+  if( fillInColumnList(pParse, p) ){
+    return 0;
+  }
+  nColumn = p->pEList->nExpr;
+  pKeyInfo = sqliteMalloc( sizeof(*pKeyInfo)+nColumn*sizeof(CollSeq*) );
+  if( pKeyInfo==0 ) return 0;
+  pKeyInfo->enc = db->enc;
+  pKeyInfo->nField = nColumn;
+  for(i=0; i<nColumn; i++){
+    pKeyInfo->aColl[i] = sqlite3ExprCollSeq(pParse, p->pEList->a[i].pExpr);
+    if( !pKeyInfo->aColl[i] ){
+      pKeyInfo->aColl[i] = db->pDfltColl;
+    }
+  }
+  addr = sqlite3VdbeOp3(v, OP_OpenTemp, iTab, 0, 
+      (char*)pKeyInfo, P3_KEYINFO_HANDOFF);
+  if( keyAsData ){
+    sqlite3VdbeAddOp(v, OP_KeyAsData, iTab, 1);
+  }
+  return addr;
+}
+
+/*
+** Add the address "addr" to the set of all OpenTemp opcode addresses
+** that are being accumulated in p->ppOpenTemp.
+*/
+static int multiSelectOpenTempAddr(Select *p, int addr){
+  IdList *pList = *p->ppOpenTemp = sqlite3IdListAppend(*p->ppOpenTemp, 0);
+  if( pList==0 ){
+    return SQLITE_NOMEM;
+  }
+  pList->a[pList->nId-1].idx = addr;
+  return SQLITE_OK;
+}
+
+/*
+** 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;
+}
+
+/*
+** 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 */
+  IdList *pOpenTemp = 0;/* OP_OpenTemp opcodes that need a KeyInfo */
+  int aAddr[5];         /* Addresses of SetNumColumns operators */
+  int nAddr = 0;        /* Number used */
+  int nCol;             /* Number of columns in the result set */
+
+  /* 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;
+  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->nLimit>=0 || pPrior->nOffset>0 ){
+    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;
+  }
+
+  /* If *p this is the right-most select statement, then initialize
+  ** p->ppOpenTemp to point to pOpenTemp.  If *p is not the right most
+  ** statement then p->ppOpenTemp will have already been initialized
+  ** by a prior call to this same procedure.  Pass along the pOpenTemp
+  ** pointer to pPrior, the next statement to our left.
+  */
+  if( p->ppOpenTemp==0 ){
+    p->ppOpenTemp = &pOpenTemp;
+  }
+  pPrior->ppOpenTemp = p->ppOpenTemp;
+
+  /* Create the destination temporary table if necessary
+  */
+  if( eDest==SRT_TempTable ){
+    assert( p->pEList );
+    sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
+    assert( nAddr==0 );
+    aAddr[nAddr++] = sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, 0);
+    eDest = SRT_Table;
+  }
+
+  /* Generate code for the left and right SELECT statements.
+  */
+  switch( p->op ){
+    case TK_ALL: {
+      if( p->pOrderBy==0 ){
+        pPrior->nLimit = p->nLimit;
+        pPrior->nOffset = p->nOffset;
+        rc = sqlite3Select(pParse, pPrior, eDest, iParm, 0, 0, 0, aff);
+        if( rc ){
+          goto multi_select_end;
+        }
+        p->pPrior = 0;
+        p->iLimit = pPrior->iLimit;
+        p->iOffset = pPrior->iOffset;
+        p->nLimit = -1;
+        p->nOffset = 0;
+        rc = sqlite3Select(pParse, p, eDest, iParm, 0, 0, 0, aff);
+        p->pPrior = pPrior;
+        if( rc ){
+          goto multi_select_end;
+        }
+        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 */
+      int nLimit, nOffset; /* Saved values of p->nLimit and p->nOffset */
+      ExprList *pOrderBy;  /* The ORDER BY clause for the right SELECT */
+      int addr;
+
+      priorOp = p->op==TK_ALL ? SRT_Table : SRT_Union;
+      if( eDest==priorOp && p->pOrderBy==0 && p->nLimit<0 && p->nOffset==0 ){
+        /* 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( p->pOrderBy 
+        && matchOrderbyToColumn(pParse, p, p->pOrderBy, unionTab, 1) ){
+          rc = 1;
+          goto multi_select_end;
+        }
+        addr = sqlite3VdbeAddOp(v, OP_OpenTemp, unionTab, 0);
+        if( p->op!=TK_ALL ){
+          rc = multiSelectOpenTempAddr(p, addr);
+          if( rc!=SQLITE_OK ){
+            goto multi_select_end;
+          }
+          sqlite3VdbeAddOp(v, OP_KeyAsData, unionTab, 1);
+        }
+	assert( nAddr<sizeof(aAddr)/sizeof(aAddr[0]) );
+        aAddr[nAddr++] = sqlite3VdbeAddOp(v, OP_SetNumColumns, unionTab, 0);
+        assert( p->pEList );
+      }
+
+      /* Code the SELECT statements to our left
+      */
+      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;
+      pOrderBy = p->pOrderBy;
+      p->pOrderBy = 0;
+      nLimit = p->nLimit;
+      p->nLimit = -1;
+      nOffset = p->nOffset;
+      p->nOffset = 0;
+      rc = sqlite3Select(pParse, p, op, unionTab, 0, 0, 0, aff);
+      p->pPrior = pPrior;
+      p->pOrderBy = pOrderBy;
+      p->nLimit = nLimit;
+      p->nOffset = nOffset;
+      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 ){
+          generateColumnNames(pParse, 0, p->pEList);
+        }
+        iBreak = sqlite3VdbeMakeLabel(v);
+        iCont = sqlite3VdbeMakeLabel(v);
+        sqlite3VdbeAddOp(v, OP_Rewind, unionTab, iBreak);
+        computeLimitRegisters(pParse, p);
+        iStart = sqlite3VdbeCurrentAddr(v);
+        rc = selectInnerLoop(pParse, p, p->pEList, unionTab, p->pEList->nExpr,
+                             p->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;
+      int nLimit, nOffset;
+      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( p->pOrderBy && matchOrderbyToColumn(pParse,p,p->pOrderBy,tab1,1) ){
+        rc = 1;
+        goto multi_select_end;
+      }
+
+      addr = sqlite3VdbeAddOp(v, OP_OpenTemp, tab1, 0);
+      rc = multiSelectOpenTempAddr(p, addr);
+      if( rc!=SQLITE_OK ){
+        goto multi_select_end;
+      }
+      sqlite3VdbeAddOp(v, OP_KeyAsData, tab1, 1);
+      assert( nAddr<sizeof(aAddr)/sizeof(aAddr[0]) );
+      aAddr[nAddr++] = sqlite3VdbeAddOp(v, OP_SetNumColumns, tab1, 0);
+      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_OpenTemp, tab2, 0);
+      rc = multiSelectOpenTempAddr(p, addr);
+      if( rc!=SQLITE_OK ){
+        goto multi_select_end;
+      }
+      sqlite3VdbeAddOp(v, OP_KeyAsData, tab2, 1);
+      assert( nAddr<sizeof(aAddr)/sizeof(aAddr[0]) );
+      aAddr[nAddr++] = sqlite3VdbeAddOp(v, OP_SetNumColumns, tab2, 0);
+      p->pPrior = 0;
+      nLimit = p->nLimit;
+      p->nLimit = -1;
+      nOffset = p->nOffset;
+      p->nOffset = 0;
+      rc = sqlite3Select(pParse, p, SRT_Union, tab2, 0, 0, 0, aff);
+      p->pPrior = pPrior;
+      p->nLimit = nLimit;
+      p->nOffset = nOffset;
+      if( rc ){
+        goto multi_select_end;
+      }
+
+      /* Generate code to take the intersection of the two temporary
+      ** tables.
+      */
+      assert( p->pEList );
+      if( eDest==SRT_Callback ){
+        generateColumnNames(pParse, 0, p->pEList);
+      }
+      iBreak = sqlite3VdbeMakeLabel(v);
+      iCont = sqlite3VdbeMakeLabel(v);
+      sqlite3VdbeAddOp(v, OP_Rewind, tab1, iBreak);
+      computeLimitRegisters(pParse, p);
+      iStart = sqlite3VdbeAddOp(v, OP_FullKey, tab1, 0);
+      sqlite3VdbeAddOp(v, OP_NotFound, tab2, iCont);
+      rc = selectInnerLoop(pParse, p, p->pEList, tab1, p->pEList->nExpr,
+                             p->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( nAddr>0 ){
+    nAddr--;
+    sqlite3VdbeChangeP2(v, aAddr[nAddr], 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( p->pOrderBy || (pOpenTemp && pOpenTemp->nId>0) ){
+    int i;                        /* Loop counter */
+    KeyInfo *pKeyInfo;            /* Collating sequence for the result set */
+
+    assert( p->ppOpenTemp == &pOpenTemp );
+    pKeyInfo = sqliteMalloc(sizeof(*pKeyInfo)+nCol*sizeof(CollSeq*));
+    if( !pKeyInfo ){
+      rc = SQLITE_NOMEM;
+      goto multi_select_end;
+    }
+
+    pKeyInfo->enc = pParse->db->enc;
+    pKeyInfo->nField = nCol;
+
+    for(i=0; i<nCol; i++){
+      pKeyInfo->aColl[i] = multiSelectCollSeq(pParse, p, i);
+      if( !pKeyInfo->aColl[i] ){
+        pKeyInfo->aColl[i] = pParse->db->pDfltColl;
+      }
+    }
+
+    for(i=0; pOpenTemp && i<pOpenTemp->nId; i++){
+      int p3type = (i==0?P3_KEYINFO_HANDOFF:P3_KEYINFO);
+      int addr = pOpenTemp->a[i].idx;
+      sqlite3VdbeChangeP3(v, addr, (char *)pKeyInfo, p3type);
+    }
+
+    if( p->pOrderBy ){
+      struct ExprList_item *pOrderByTerm = p->pOrderBy->a;
+      for(i=0; i<p->pOrderBy->nExpr; i++, pOrderByTerm++){
+        Expr *pExpr = pOrderByTerm->pExpr;
+        char *zName = pOrderByTerm->zName;
+        assert( pExpr->op==TK_COLUMN && pExpr->iColumn<nCol );
+        assert( !pExpr->pColl );
+        if( zName ){
+          pExpr->pColl = sqlite3LocateCollSeq(pParse, zName, -1);
+        }else{
+          pExpr->pColl = pKeyInfo->aColl[pExpr->iColumn];
+        }
+      }
+      generateSortTail(pParse, p, v, p->pEList->nExpr, eDest, iParm);
+    }
+
+    if( !pOpenTemp ){
+      /* This happens for UNION ALL ... ORDER BY */
+      sqliteFree(pKeyInfo);
+    }
+  }
+
+multi_select_end:
+  if( pOpenTemp ){
+    sqlite3IdListDelete(pOpenTemp);
+  }
+  p->ppOpenTemp = 0;
+  return rc;
+}
+
+/*
+** 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 substExprList(ExprList*,int,ExprList*);  /* Forward Decl */
+static void substExpr(Expr *pExpr, int iTable, ExprList *pEList){
+  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(pNew->pLeft);
+      assert( pExpr->pRight==0 );
+      pExpr->pRight = sqlite3ExprDup(pNew->pRight);
+      assert( pExpr->pList==0 );
+      pExpr->pList = sqlite3ExprListDup(pNew->pList);
+      pExpr->iTable = pNew->iTable;
+      pExpr->iColumn = pNew->iColumn;
+      pExpr->iAgg = pNew->iAgg;
+      sqlite3TokenCopy(&pExpr->token, &pNew->token);
+      sqlite3TokenCopy(&pExpr->span, &pNew->span);
+    }
+  }else{
+    substExpr(pExpr->pLeft, iTable, pEList);
+    substExpr(pExpr->pRight, iTable, pEList);
+    substExprList(pExpr->pList, iTable, pEList);
+  }
+}
+static void 
+substExprList(ExprList *pList, int iTable, ExprList *pEList){
+  int i;
+  if( pList==0 ) return;
+  for(i=0; i<pList->nExpr; i++){
+    substExpr(pList->a[i].pExpr, iTable, pEList);
+  }
+}
+
+/*
+** 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)
+**
+** 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(
+  Parse *pParse,       /* The parsing context */
+  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 */
+  struct 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;
+  if( subqueryIsAgg && pSrc->nSrc>1 ) return 0;
+  pSubSrc = pSub->pSrc;
+  assert( pSubSrc );
+  if( pSubSrc->nSrc==0 ) return 0;
+  if( (pSub->isDistinct || pSub->nLimit>=0) &&  (pSrc->nSrc>1 || isAgg) ){
+     return 0;
+  }
+  if( (p->isDistinct || p->nLimit>=0) && subqueryIsAgg ) return 0;
+  if( p->pOrderBy && pSub->pOrderBy ) return 0;
+
+  /* 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 && iFrom>0 && (pSrc->a[iFrom-1].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( iFrom>0 && (pSrc->a[iFrom-1].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;
+    Table *pTab = pSubitem->pTab;
+
+    if( pTab && pTab->isTransient ){
+      sqlite3DeleteTable(0, pSubitem->pTab);
+    }
+    sqliteFree(pSubitem->zDatabase);
+    sqliteFree(pSubitem->zName);
+    sqliteFree(pSubitem->zAlias);
+    if( nSubSrc>1 ){
+      int extra = nSubSrc - 1;
+      for(i=1; i<nSubSrc; i++){
+        pSrc = sqlite3SrcListAppend(pSrc, 0, 0);
+      }
+      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+nSubSrc-1].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".
+  */
+  substExprList(p->pEList, iParent, pSub->pEList);
+  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 = sqliteStrNDup(pExpr->span.z, pExpr->span.n);
+    }
+  }
+  if( isAgg ){
+    substExprList(p->pGroupBy, iParent, pSub->pEList);
+    substExpr(p->pHaving, iParent, pSub->pEList);
+  }
+  if( pSub->pOrderBy ){
+    assert( p->pOrderBy==0 );
+    p->pOrderBy = pSub->pOrderBy;
+    pSub->pOrderBy = 0;
+  }else if( p->pOrderBy ){
+    substExprList(p->pOrderBy, iParent, pSub->pEList);
+  }
+  if( pSub->pWhere ){
+    pWhere = sqlite3ExprDup(pSub->pWhere);
+  }else{
+    pWhere = 0;
+  }
+  if( subqueryIsAgg ){
+    assert( p->pHaving==0 );
+    p->pHaving = p->pWhere;
+    p->pWhere = pWhere;
+    substExpr(p->pHaving, iParent, pSub->pEList);
+    p->pHaving = sqlite3ExprAnd(p->pHaving, sqlite3ExprDup(pSub->pHaving));
+    assert( p->pGroupBy==0 );
+    p->pGroupBy = sqlite3ExprListDup(pSub->pGroupBy);
+  }else{
+    substExpr(p->pWhere, iParent, pSub->pEList);
+    p->pWhere = sqlite3ExprAnd(p->pWhere, pWhere);
+  }
+
+  /* The flattened query is distinct if either the inner or the
+  ** outer query is distinct. 
+  */
+  p->isDistinct = p->isDistinct || pSub->isDistinct;
+
+  /* Transfer the limit expression from the subquery to the outer
+  ** query.
+  */
+  if( pSub->nLimit>=0 ){
+    if( p->nLimit<0 ){
+      p->nLimit = pSub->nLimit;
+    }else if( p->nLimit+p->nOffset > pSub->nLimit+pSub->nOffset ){
+      p->nLimit = pSub->nLimit + pSub->nOffset - p->nOffset;
+    }
+  }
+  p->nOffset += pSub->nOffset;
+
+  /* Finially, delete what is left of the subquery and return
+  ** success.
+  */
+  sqlite3SelectDelete(pSub);
+  return 1;
+}
+
+/*
+** 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;
+  int cont;
+  ExprList *pEList, *pList, eList;
+  struct ExprList_item eListItem;
+  SrcList *pSrc;
+  
+
+  /* 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(pExpr->token.z,"min",3)==0 ){
+    seekOp = OP_Rewind;
+  }else if( sqlite3StrNICmp(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;
+
+  /* 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);
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      assert( pIdx->nColumn>=1 );
+      if( pIdx->aiColumn[0]==iCol && pIdx->keyInfo.aColl[0]==pColl ) 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_TempTable ){
+    sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
+    sqlite3VdbeAddOp(v, OP_SetNumColumns, 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.
+  */
+  sqlite3CodeVerifySchema(pParse, pTab->iDb);
+  base = pSrc->a[0].iCursor;
+  computeLimitRegisters(pParse, p);
+  if( pSrc->a[0].pSelect==0 ){
+    sqlite3OpenTableForReading(v, base, pTab);
+  }
+  cont = sqlite3VdbeMakeLabel(v);
+  if( pIdx==0 ){
+    sqlite3VdbeAddOp(v, seekOp, base, 0);
+  }else{
+    sqlite3VdbeAddOp(v, OP_Integer, pIdx->iDb, 0);
+    sqlite3VdbeOp3(v, OP_OpenRead, base+1, pIdx->tnum,
+                   (char*)&pIdx->keyInfo, P3_KEYINFO);
+    if( seekOp==OP_Rewind ){
+      sqlite3VdbeAddOp(v, OP_String, 0, 0);
+      sqlite3VdbeAddOp(v, OP_MakeRecord, 1, 0);
+      seekOp = OP_MoveGt;
+    }
+    sqlite3VdbeAddOp(v, seekOp, base+1, 0);
+    sqlite3VdbeAddOp(v, OP_IdxRecno, base+1, 0);
+    sqlite3VdbeAddOp(v, OP_Close, base+1, 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, cont, cont, 0);
+  sqlite3VdbeResolveLabel(v, cont);
+  sqlite3VdbeAddOp(v, OP_Close, base, 0);
+  
+  return 1;
+}
+
+/*
+** Analyze and ORDER BY or GROUP BY clause in a SELECT statement.  Return
+** the number of errors seen.
+**
+** An ORDER BY or GROUP BY is a list of expressions.  If any expression
+** is an integer constant, then that expression is replaced by the
+** corresponding entry in the result set.
+*/
+static int processOrderGroupBy(
+  Parse *pParse,        /* Parsing context */
+  ExprList *pOrderBy,   /* The ORDER BY or GROUP BY clause to be processed */
+  SrcList *pTabList,    /* The FROM clause */
+  ExprList *pEList,     /* The result set */
+  int isAgg,            /* True if aggregate functions are involved */
+  const char *zType     /* Either "ORDER" or "GROUP", as appropriate */
+){
+  int i;
+  if( pOrderBy==0 ) return 0;
+  for(i=0; i<pOrderBy->nExpr; i++){
+    int iCol;
+    Expr *pE = pOrderBy->a[i].pExpr;
+    if( sqlite3ExprIsInteger(pE, &iCol) && iCol>0 && iCol<=pEList->nExpr ){
+      sqlite3ExprDelete(pE);
+      pE = pOrderBy->a[i].pExpr = sqlite3ExprDup(pEList->a[iCol-1].pExpr);
+    }
+    if( sqlite3ExprResolveAndCheck(pParse, pTabList, pEList, pE, isAgg, 0) ){
+      return 1;
+    }
+    if( sqlite3ExprIsConstant(pE) ){
+      if( sqlite3ExprIsInteger(pE, &iCol)==0 ){
+        sqlite3ErrorMsg(pParse,
+          "%s BY terms must not be non-integer constants", zType);
+        return 1;
+      }else if( iCol<=0 || iCol>pEList->nExpr ){
+        sqlite3ErrorMsg(pParse, 
+           "%s BY column number %d out of range - should be "
+           "between 1 and %d", zType, iCol, pEList->nExpr);
+        return 1;
+      }
+    }
+  }
+  return 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;
+  WhereInfo *pWInfo;
+  Vdbe *v;
+  int isAgg = 0;         /* 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 */
+
+  if( sqlite3_malloc_failed || pParse->nErr || p==0 ) return 1;
+  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
+
+  /* If there is are a sequence of queries, do the earlier ones first.
+  */
+  if( p->pPrior ){
+    return multiSelect(pParse, p, eDest, iParm, aff);
+  }
+
+  /* Make local copies of the parameters for this query.
+  */
+  pTabList = p->pSrc;
+  pWhere = p->pWhere;
+  pOrderBy = p->pOrderBy;
+  pGroupBy = p->pGroupBy;
+  pHaving = p->pHaving;
+  isDistinct = p->isDistinct;
+
+  /* Allocate VDBE cursors for each table in the FROM clause
+  */
+  sqlite3SrcListAssignCursors(pParse, pTabList);
+
+  /* 
+  ** 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;
+
+  /* Expand any "*" terms in the result set.  (For example the "*" in
+  ** "SELECT * FROM t1")  The fillInColumnlist() routine also does some
+  ** other housekeeping - see the header comment for details.
+  */
+  if( fillInColumnList(pParse, p) ){
+    goto select_end;
+  }
+  pWhere = p->pWhere;
+  pEList = p->pEList;
+  if( pEList==0 ) goto select_end;
+
+  /* If writing to memory or generating a set
+  ** only a single column may be output.
+  */
+  if( (eDest==SRT_Mem || eDest==SRT_Set) && pEList->nExpr>1 ){
+    sqlite3ErrorMsg(pParse, "only a single result allowed for "
+       "a SELECT that is part of an expression");
+    goto select_end;
+  }
+
+  /* ORDER BY is ignored for some destinations.
+  */
+  switch( eDest ){
+    case SRT_Union:
+    case SRT_Except:
+    case SRT_Discard:
+      pOrderBy = 0;
+      break;
+    default:
+      break;
+  }
+
+  /* At this point, we should have allocated all the cursors that we
+  ** need to handle subquerys and temporary tables.  
+  **
+  ** Resolve the column names and do a semantics check on all the expressions.
+  */
+  for(i=0; i<pEList->nExpr; i++){
+    if( sqlite3ExprResolveAndCheck(pParse, pTabList, 0, pEList->a[i].pExpr,
+                                    1, &isAgg) ){
+      goto select_end;
+    }
+  }
+  if( sqlite3ExprResolveAndCheck(pParse, pTabList, pEList, pWhere, 0, 0) ){
+    goto select_end;
+  }
+  if( pHaving ){
+    if( pGroupBy==0 ){
+      sqlite3ErrorMsg(pParse, "a GROUP BY clause is required before HAVING");
+      goto select_end;
+    }
+    if( sqlite3ExprResolveAndCheck(pParse, pTabList, pEList,pHaving,1,&isAgg) ){
+      goto select_end;
+    }
+  }
+  if( processOrderGroupBy(pParse, pOrderBy, pTabList, pEList, isAgg, "ORDER")
+   || processOrderGroupBy(pParse, pGroupBy, pTabList, pEList, isAgg, "GROUP")
+  ){
+    goto select_end;
+  }
+
+  /* Begin generating code.
+  */
+  v = sqlite3GetVdbe(pParse);
+  if( v==0 ) goto 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( eDest==SRT_Callback ){
+    generateColumnNames(pParse, pTabList, pEList);
+  }
+
+  /* Generate code for all sub-queries in the FROM clause
+  */
+  for(i=0; i<pTabList->nSrc; i++){
+    const char *zSavedAuthContext = 0;
+    int needRestoreContext;
+
+    if( pTabList->a[i].pSelect==0 ) continue;
+    if( pTabList->a[i].zName!=0 ){
+      zSavedAuthContext = pParse->zAuthContext;
+      pParse->zAuthContext = pTabList->a[i].zName;
+      needRestoreContext = 1;
+    }else{
+      needRestoreContext = 0;
+    }
+    sqlite3Select(pParse, pTabList->a[i].pSelect, SRT_TempTable, 
+                 pTabList->a[i].iCursor, p, i, &isAgg, 0);
+    if( needRestoreContext ){
+      pParse->zAuthContext = zSavedAuthContext;
+    }
+    pTabList = p->pSrc;
+    pWhere = p->pWhere;
+    if( eDest!=SRT_Union && eDest!=SRT_Except && eDest!=SRT_Discard ){
+      pOrderBy = p->pOrderBy;
+    }
+    pGroupBy = p->pGroupBy;
+    pHaving = p->pHaving;
+    isDistinct = p->isDistinct;
+  }
+
+  /* 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.  
+  */
+  if( pParent && pParentAgg &&
+      flattenSubquery(pParse, pParent, parentTab, *pParentAgg, isAgg) ){
+    if( isAgg ) *pParentAgg = 1;
+    return rc;
+  }
+
+  /* If there is an ORDER BY clause, resolve any collation sequences
+  ** names that have been explicitly specified.
+  */
+  if( pOrderBy ){
+    for(i=0; i<pOrderBy->nExpr; i++){
+      if( pOrderBy->a[i].zName ){
+        pOrderBy->a[i].pExpr->pColl = 
+            sqlite3LocateCollSeq(pParse, pOrderBy->a[i].zName, -1);
+      }
+    }
+    if( pParse->nErr ){
+      goto select_end;
+    }
+  }
+
+  /* Set the limiter.
+  */
+  computeLimitRegisters(pParse, p);
+
+  /* If the output is destined for a temporary table, open that table.
+  */
+  if( eDest==SRT_TempTable ){
+    sqlite3VdbeAddOp(v, OP_OpenTemp, iParm, 0);
+    sqlite3VdbeAddOp(v, OP_SetNumColumns, iParm, pEList->nExpr);
+  }
+
+  /* Do an analysis of aggregate expressions.
+  */
+  sqliteAggregateInfoReset(pParse);
+  if( isAgg || pGroupBy ){
+    assert( pParse->nAgg==0 );
+    isAgg = 1;
+    for(i=0; i<pEList->nExpr; i++){
+      if( sqlite3ExprAnalyzeAggregates(pParse, pEList->a[i].pExpr) ){
+        goto select_end;
+      }
+    }
+    if( pGroupBy ){
+      for(i=0; i<pGroupBy->nExpr; i++){
+        if( sqlite3ExprAnalyzeAggregates(pParse, pGroupBy->a[i].pExpr) ){
+          goto select_end;
+        }
+      }
+    }
+    if( pHaving && sqlite3ExprAnalyzeAggregates(pParse, pHaving) ){
+      goto select_end;
+    }
+    if( pOrderBy ){
+      for(i=0; i<pOrderBy->nExpr; i++){
+        if( sqlite3ExprAnalyzeAggregates(pParse, pOrderBy->a[i].pExpr) ){
+          goto select_end;
+        }
+      }
+    }
+  }
+
+  /* Reset the aggregator
+  */
+  if( isAgg ){
+    int addr = sqlite3VdbeAddOp(v, OP_AggReset, (pGroupBy?0:1), pParse->nAgg);
+    for(i=0; i<pParse->nAgg; i++){
+      FuncDef *pFunc;
+      if( (pFunc = pParse->aAgg[i].pFunc)!=0 && pFunc->xFinalize!=0 ){
+        sqlite3VdbeOp3(v, OP_AggInit, 0, i, (char*)pFunc, P3_FUNCDEF);
+      }
+    }
+    if( pGroupBy ){
+      int sz = sizeof(KeyInfo) + pGroupBy->nExpr*sizeof(CollSeq*);
+      KeyInfo *pKey = (KeyInfo *)sqliteMalloc(sz);
+      if( 0==pKey ){
+        goto select_end;
+      }
+      pKey->enc = pParse->db->enc;
+      pKey->nField = pGroupBy->nExpr;
+      for(i=0; i<pGroupBy->nExpr; i++){
+        pKey->aColl[i] = sqlite3ExprCollSeq(pParse, pGroupBy->a[i].pExpr);
+        if( !pKey->aColl[i] ){
+          pKey->aColl[i] = pParse->db->pDfltColl;
+        }
+      }
+      sqlite3VdbeChangeP3(v, addr, (char *)pKey, P3_KEYINFO_HANDOFF);
+    }
+  }
+
+  /* Initialize the memory cell to NULL
+  */
+  if( eDest==SRT_Mem ){
+    sqlite3VdbeAddOp(v, OP_String8, 0, 0);
+    sqlite3VdbeAddOp(v, OP_MemStore, iParm, 1);
+  }
+
+  /* Open a temporary table to use for the distinct set.
+  */
+  if( isDistinct ){
+    distinct = pParse->nTab++;
+    openTempIndex(pParse, p, distinct, 0);
+  }else{
+    distinct = -1;
+  }
+
+  /* Begin the database scan
+  */
+  pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 
+                            pGroupBy ? 0 : &pOrderBy);
+  if( pWInfo==0 ) goto select_end;
+
+  /* Use the standard inner loop if we are not dealing with
+  ** aggregates
+  */
+  if( !isAgg ){
+    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
+                    iParm, pWInfo->iContinue, pWInfo->iBreak, aff) ){
+       goto select_end;
+    }
+  }
+
+  /* If we are dealing with aggregates, then do the special aggregate
+  ** processing.  
+  */
+  else{
+    AggExpr *pAgg;
+    if( pGroupBy ){
+      int lbl1;
+      for(i=0; i<pGroupBy->nExpr; i++){
+        sqlite3ExprCode(pParse, pGroupBy->a[i].pExpr);
+      }
+      /* No affinity string is attached to the following OP_MakeRecord 
+      ** because we do not need to do any coercion of datatypes. */
+      sqlite3VdbeAddOp(v, OP_MakeRecord, pGroupBy->nExpr, 0);
+      lbl1 = sqlite3VdbeMakeLabel(v);
+      sqlite3VdbeAddOp(v, OP_AggFocus, 0, lbl1);
+      for(i=0, pAgg=pParse->aAgg; i<pParse->nAgg; i++, pAgg++){
+        if( pAgg->isAgg ) continue;
+        sqlite3ExprCode(pParse, pAgg->pExpr);
+        sqlite3VdbeAddOp(v, OP_AggSet, 0, i);
+      }
+      sqlite3VdbeResolveLabel(v, lbl1);
+    }
+    for(i=0, pAgg=pParse->aAgg; i<pParse->nAgg; i++, pAgg++){
+      Expr *pE;
+      int nExpr;
+      FuncDef *pDef;
+      if( !pAgg->isAgg ) continue;
+      assert( pAgg->pFunc!=0 );
+      assert( pAgg->pFunc->xStep!=0 );
+      pDef = pAgg->pFunc;
+      pE = pAgg->pExpr;
+      assert( pE!=0 );
+      assert( pE->op==TK_AGG_FUNCTION );
+      nExpr = sqlite3ExprCodeExprList(pParse, pE->pList);
+      sqlite3VdbeAddOp(v, OP_Integer, i, 0);
+      if( pDef->needCollSeq ){
+        CollSeq *pColl = 0;
+        int j;
+        for(j=0; !pColl && j<nExpr; j++){
+          pColl = sqlite3ExprCollSeq(pParse, pE->pList->a[j].pExpr);
+        }
+        if( !pColl ) pColl = pParse->db->pDfltColl;
+        sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
+      }
+      sqlite3VdbeOp3(v, OP_AggFunc, 0, nExpr, (char*)pDef, P3_POINTER);
+    }
+  }
+
+  /* End the database scan loop.
+  */
+  sqlite3WhereEnd(pWInfo);
+
+  /* If we are processing aggregates, we need to set up a second loop
+  ** over all of the aggregate values and process them.
+  */
+  if( isAgg ){
+    int endagg = sqlite3VdbeMakeLabel(v);
+    int startagg;
+    startagg = sqlite3VdbeAddOp(v, OP_AggNext, 0, endagg);
+    pParse->useAgg = 1;
+    if( pHaving ){
+      sqlite3ExprIfFalse(pParse, pHaving, startagg, 1);
+    }
+    if( selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, distinct, eDest,
+                    iParm, startagg, endagg, aff) ){
+      goto select_end;
+    }
+    sqlite3VdbeAddOp(v, OP_Goto, 0, startagg);
+    sqlite3VdbeResolveLabel(v, endagg);
+    sqlite3VdbeAddOp(v, OP_Noop, 0, 0);
+    pParse->useAgg = 0;
+  }
+
+  /* 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);
+  }
+
+  /* If this was a subquery, we have now converted the subquery into a
+  ** temporary table.  So delete the subquery structure from the parent
+  ** to prevent this subquery from being evaluated again and to force the
+  ** the use of the temporary table.
+  */
+  if( pParent ){
+    assert( pParent->pSrc->nSrc>parentTab );
+    assert( pParent->pSrc->a[parentTab].pSelect==p );
+    sqlite3SelectDelete(p);
+    pParent->pSrc->a[parentTab].pSelect = 0;
+  }
+
+  /* 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:
+  sqliteAggregateInfoReset(pParse);
+  return rc;
+}