FCL/sf/app/podcatcher: comparison engine/sqlite/src/expr.cpp

equal deleted inserted replaced

-:5f8e5adbbed9
+:29cda98b007e
+/*
+** 2001 September 15
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains routines used for analyzing expressions and
+** for generating VDBE code that evaluates expressions in SQLite.
+**
+** $Id: expr.cpp 1282 2008-11-13 09:31:33Z LarsPson $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+/*
+** Return the 'affinity' of the expression pExpr if any.
+**
+** If pExpr is a column, a reference to a column via an 'AS' alias,
+** or a sub-select with a column as the return value, then the
+** affinity of that column is returned. Otherwise, 0x00 is returned,
+** indicating no affinity for the expression.
+**
+** i.e. the WHERE clause expresssions in the following statements all
+** have an affinity:
+**
+** CREATE TABLE t1(a);
+** SELECT * FROM t1 WHERE a;
+** SELECT a AS b FROM t1 WHERE b;
+** SELECT * FROM t1 WHERE (select a from t1);
+*/
+char sqlite3ExprAffinity(Expr *pExpr){
+int op = pExpr->op;
+if( op==TK_SELECT ){
+return sqlite3ExprAffinity(pExpr->pSelect->pEList->a[0].pExpr);
+}
+#ifndef SQLITE_OMIT_CAST
+if( op==TK_CAST ){
+return sqlite3AffinityType(&pExpr->token);
+}
+#endif
+return pExpr->affinity;
+}
+/*
+** Set the collating sequence for expression pExpr to be the collating
+** sequence named by pToken.   Return a pointer to the revised expression.
+** The collating sequence is marked as "explicit" using the EP_ExpCollate
+** flag.  An explicit collating sequence will override implicit
+** collating sequences.
+*/
+Expr *sqlite3ExprSetColl(Parse *pParse, Expr *pExpr, Token *pName){
+char *zColl = 0;            /* Dequoted name of collation sequence */
+CollSeq *pColl;
+zColl = sqlite3NameFromToken(pParse->db, pName);
+if( pExpr && zColl ){
+pColl = sqlite3LocateCollSeq(pParse, zColl, -1);
+if( pColl ){
+pExpr->pColl = pColl;
+pExpr->flags |= EP_ExpCollate;
+}
+}
+sqlite3_free(zColl);
+return pExpr;
+}
+/*
+** Return the default collation sequence for the expression pExpr. If
+** there is no default collation type, return 0.
+*/
+CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
+CollSeq *pColl = 0;
+if( pExpr ){
+int op;
+pColl = pExpr->pColl;
+op = pExpr->op;
+if( (op==TK_CAST || op==TK_UPLUS) && !pColl ){
+return sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+}
+}
+if( sqlite3CheckCollSeq(pParse, pColl) ){
+pColl = 0;
+}
+return pColl;
+}
+/*
+** pExpr is an operand of a comparison operator.  aff2 is the
+** type affinity of the other operand.  This routine returns the
+** type affinity that should be used for the comparison operator.
+*/
+char sqlite3CompareAffinity(Expr *pExpr, char aff2){
+char aff1 = sqlite3ExprAffinity(pExpr);
+if( aff1 && aff2 ){
+/* Both sides of the comparison are columns. If one has numeric
+** affinity, use that. Otherwise use no affinity.
+*/
+if( sqlite3IsNumericAffinity(aff1) || sqlite3IsNumericAffinity(aff2) ){
+return SQLITE_AFF_NUMERIC;
+}else{
+return SQLITE_AFF_NONE;
+}
+}else if( !aff1 && !aff2 ){
+/* Neither side of the comparison is a column.  Compare the
+** results directly.
+*/
+return SQLITE_AFF_NONE;
+}else{
+/* One side is a column, the other is not. Use the columns affinity. */
+assert( aff1==0 || aff2==0 );
+return (aff1 + aff2);
+}
+}
+/*
+** pExpr is a comparison operator.  Return the type affinity that should
+** be applied to both operands prior to doing the comparison.
+*/
+static char comparisonAffinity(Expr *pExpr){
+char aff;
+assert( pExpr->op==TK_EQ || pExpr->op==TK_IN || pExpr->op==TK_LT ||
+pExpr->op==TK_GT || pExpr->op==TK_GE || pExpr->op==TK_LE ||
+pExpr->op==TK_NE );
+assert( pExpr->pLeft );
+aff = sqlite3ExprAffinity(pExpr->pLeft);
+if( pExpr->pRight ){
+aff = sqlite3CompareAffinity(pExpr->pRight, aff);
+}
+else if( pExpr->pSelect ){
+aff = sqlite3CompareAffinity(pExpr->pSelect->pEList->a[0].pExpr, aff);
+}
+else if( !aff ){
+aff = SQLITE_AFF_NONE;
+}
+return aff;
+}
+/*
+** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
+** idx_affinity is the affinity of an indexed column. Return true
+** if the index with affinity idx_affinity may be used to implement
+** the comparison in pExpr.
+*/
+int sqlite3IndexAffinityOk(Expr *pExpr, char idx_affinity){
+char aff = comparisonAffinity(pExpr);
+switch( aff ){
+case SQLITE_AFF_NONE:
+return 1;
+case SQLITE_AFF_TEXT:
+return idx_affinity==SQLITE_AFF_TEXT;
+default:
+return sqlite3IsNumericAffinity(idx_affinity);
+}
+}
+/*
+** Return the P1 value that should be used for a binary comparison
+** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
+** If jumpIfNull is true, then set the low byte of the returned
+** P1 value to tell the opcode to jump if either expression
+** evaluates to NULL.
+*/
+static int binaryCompareP1(Expr *pExpr1, Expr *pExpr2, int jumpIfNull){
+char aff = sqlite3ExprAffinity(pExpr2);
+return ((int)sqlite3CompareAffinity(pExpr1, aff))+(jumpIfNull?0x100:0);
+}
+/*
+** Return a pointer to the collation sequence that should be used by
+** a binary comparison operator comparing pLeft and pRight.
+**
+** If the left hand expression has a collating sequence type, then it is
+** used. Otherwise the collation sequence for the right hand expression
+** is used, or the default (BINARY) if neither expression has a collating
+** type.
+**
+** Argument pRight (but not pLeft) may be a null pointer. In this case,
+** it is not considered.
+*/
+CollSeq *sqlite3BinaryCompareCollSeq(
+Parse *pParse,
+Expr *pLeft,
+Expr *pRight
+){
+CollSeq *pColl;
+assert( pLeft );
+if( pLeft->flags & EP_ExpCollate ){
+assert( pLeft->pColl );
+pColl = pLeft->pColl;
+}else if( pRight && pRight->flags & EP_ExpCollate ){
+assert( pRight->pColl );
+pColl = pRight->pColl;
+}else{
+pColl = sqlite3ExprCollSeq(pParse, pLeft);
+if( !pColl ){
+pColl = sqlite3ExprCollSeq(pParse, pRight);
+}
+}
+return pColl;
+}
+/*
+** Generate code for a comparison operator.
+*/
+static int codeCompare(
+Parse *pParse,    /* The parsing (and code generating) context */
+Expr *pLeft,      /* The left operand */
+Expr *pRight,     /* The right operand */
+int opcode,       /* The comparison opcode */
+int dest,         /* Jump here if true.  */
+int jumpIfNull    /* If true, jump if either operand is NULL */
+){
+int p1 = binaryCompareP1(pLeft, pRight, jumpIfNull);
+CollSeq *p3 = sqlite3BinaryCompareCollSeq(pParse, pLeft, pRight);
+return sqlite3VdbeOp3(pParse->pVdbe, opcode, p1, dest, (const char*)p3, P3_COLLSEQ);
+}
+/*
+** Construct a new expression node and return a pointer to it.  Memory
+** for this node is obtained from sqlite3_malloc().  The calling function
+** is responsible for making sure the node eventually gets freed.
+*/
+Expr *sqlite3Expr(
+sqlite3 *db,            /* Handle for sqlite3DbMallocZero() (may be null) */
+int op,                 /* Expression opcode */
+Expr *pLeft,            /* Left operand */
+Expr *pRight,           /* Right operand */
+const Token *pToken     /* Argument token */
+){
+Expr *pNew;
+pNew = (Expr*)sqlite3DbMallocZero(db, sizeof(Expr));
+if( pNew==0 ){
+/* When malloc fails, delete pLeft and pRight. Expressions passed to
+** this function must always be allocated with sqlite3Expr() for this
+** reason.
+*/
+sqlite3ExprDelete(pLeft);
+sqlite3ExprDelete(pRight);
+return 0;
+}
+pNew->op = op;
+pNew->pLeft = pLeft;
+pNew->pRight = pRight;
+pNew->iAgg = -1;
+if( pToken ){
+assert( pToken->dyn==0 );
+pNew->span = pNew->token = *pToken;
+}else if( pLeft ){
+if( pRight ){
+sqlite3ExprSpan(pNew, &pLeft->span, &pRight->span);
+if( pRight->flags & EP_ExpCollate ){
+pNew->flags |= EP_ExpCollate;
+pNew->pColl = pRight->pColl;
+}
+}
+if( pLeft->flags & EP_ExpCollate ){
+pNew->flags |= EP_ExpCollate;
+pNew->pColl = pLeft->pColl;
+}
+}
+sqlite3ExprSetHeight(pNew);
+return pNew;
+}
+/*
+** Works like sqlite3Expr() except that it takes an extra Parse*
+** argument and notifies the associated connection object if malloc fails.
+*/
+Expr *sqlite3PExpr(
+Parse *pParse,          /* Parsing context */
+int op,                 /* Expression opcode */
+Expr *pLeft,            /* Left operand */
+Expr *pRight,           /* Right operand */
+const Token *pToken     /* Argument token */
+){
+return sqlite3Expr(pParse->db, op, pLeft, pRight, pToken);
+}
+/*
+** When doing a nested parse, you can include terms in an expression
+** that look like this:   #0 #1 #2 ...  These terms refer to elements
+** on the stack.  "#0" means the top of the stack.
+** "#1" means the next down on the stack.  And so forth.
+**
+** This routine is called by the parser to deal with on of those terms.
+** It immediately generates code to store the value in a memory location.
+** The returns an expression that will code to extract the value from
+** that memory location as needed.
+*/
+Expr *sqlite3RegisterExpr(Parse *pParse, Token *pToken){
+Vdbe *v = pParse->pVdbe;
+Expr *p;
+int depth;
+if( pParse->nested==0 ){
+sqlite3ErrorMsg(pParse, "near \"%T\": syntax error", pToken);
+return sqlite3PExpr(pParse, TK_NULL, 0, 0, 0);
+}
+if( v==0 ) return 0;
+p = sqlite3PExpr(pParse, TK_REGISTER, 0, 0, pToken);
+if( p==0 ){
+return 0;  /* Malloc failed */
+}
+depth = atoi((char*)&pToken->z[1]);
+p->iTable = pParse->nMem++;
+sqlite3VdbeAddOp(v, OP_Dup, depth, 0);
+sqlite3VdbeAddOp(v, OP_MemStore, p->iTable, 1);
+return p;
+}
+/*
+** Join two expressions using an AND operator.  If either expression is
+** NULL, then just return the other expression.
+*/
+Expr *sqlite3ExprAnd(sqlite3 *db, Expr *pLeft, Expr *pRight){
+if( pLeft==0 ){
+return pRight;
+}else if( pRight==0 ){
+return pLeft;
+}else{
+return sqlite3Expr(db, TK_AND, pLeft, pRight, 0);
+}
+}
+/*
+** Set the Expr.span field of the given expression to span all
+** text between the two given tokens.
+*/
+void sqlite3ExprSpan(Expr *pExpr, Token *pLeft, Token *pRight){
+assert( pRight!=0 );
+assert( pLeft!=0 );
+if( pExpr && pRight->z && pLeft->z ){
+assert( pLeft->dyn==0 || pLeft->z[pLeft->n]==0 );
+if( pLeft->dyn==0 && pRight->dyn==0 ){
+pExpr->span.z = pLeft->z;
+pExpr->span.n = pRight->n + (pRight->z - pLeft->z);
+}else{
+pExpr->span.z = 0;
+}
+}
+}
+/*
+** Construct a new expression node for a function with multiple
+** arguments.
+*/
+Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
+Expr *pNew;
+assert( pToken );
+pNew = (Expr*)sqlite3DbMallocZero(pParse->db, sizeof(Expr) );
+if( pNew==0 ){
+sqlite3ExprListDelete(pList); /* Avoid leaking memory when malloc fails */
+return 0;
+}
+pNew->op = TK_FUNCTION;
+pNew->pList = pList;
+assert( pToken->dyn==0 );
+pNew->token = *pToken;
+pNew->span = pNew->token;
+sqlite3ExprSetHeight(pNew);
+return pNew;
+}
+/*
+** Assign a variable number to an expression that encodes a wildcard
+** in the original SQL statement.
+**
+** Wildcards consisting of a single "?" are assigned the next sequential
+** variable number.
+**
+** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
+** sure "nnn" is not too be to avoid a denial of service attack when
+** the SQL statement comes from an external source.
+**
+** Wildcards of the form ":aaa" or "$aaa" are assigned the same number
+** as the previous instance of the same wildcard.  Or if this is the first
+** instance of the wildcard, the next sequenial variable number is
+** assigned.
+*/
+void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
+Token *pToken;
+sqlite3 *db = pParse->db;
+if( pExpr==0 ) return;
+pToken = &pExpr->token;
+assert( pToken->n>=1 );
+assert( pToken->z!=0 );
+assert( pToken->z[0]!=0 );
+if( pToken->n==1 ){
+/* Wildcard of the form "?".  Assign the next variable number */
+pExpr->iTable = ++pParse->nVar;
+}else if( pToken->z[0]=='?' ){
+/* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
+** use it as the variable number */
+int i;
+pExpr->iTable = i = atoi((char*)&pToken->z[1]);
+if( i<1 || i>SQLITE_MAX_VARIABLE_NUMBER ){
+sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
+SQLITE_MAX_VARIABLE_NUMBER);
+}
+if( i>pParse->nVar ){
+pParse->nVar = i;
+}
+}else{
+/* Wildcards of the form ":aaa" or "$aaa".  Reuse the same variable
+** number as the prior appearance of the same name, or if the name
+** has never appeared before, reuse the same variable number
+*/
+int i, n;
+n = pToken->n;
+for(i=0; i<pParse->nVarExpr; i++){
+Expr *pE;
+if( (pE = pParse->apVarExpr[i])!=0
+&& pE->token.n==n
+&& memcmp(pE->token.z, pToken->z, n)==0 ){
+pExpr->iTable = pE->iTable;
+break;
+}
+}
+if( i>=pParse->nVarExpr ){
+pExpr->iTable = ++pParse->nVar;
+if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
+pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
+pParse->apVarExpr =
+(Expr**)sqlite3DbReallocOrFree(
+db,
+pParse->apVarExpr,
+pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
+);
+}
+if( !db->mallocFailed ){
+assert( pParse->apVarExpr!=0 );
+pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
+}
+}
+}
+if( !pParse->nErr && pParse->nVar>SQLITE_MAX_VARIABLE_NUMBER ){
+sqlite3ErrorMsg(pParse, "too many SQL variables");
+}
+}
+/*
+** Recursively delete an expression tree.
+*/
+void sqlite3ExprDelete(Expr *p){
+if( p==0 ) return;
+if( p->span.dyn ) sqlite3_free((char*)p->span.z);
+if( p->token.dyn ) sqlite3_free((char*)p->token.z);
+sqlite3ExprDelete(p->pLeft);
+sqlite3ExprDelete(p->pRight);
+sqlite3ExprListDelete(p->pList);
+sqlite3SelectDelete(p->pSelect);
+sqlite3_free(p);
+}
+/*
+** The Expr.token field might be a string literal that is quoted.
+** If so, remove the quotation marks.
+*/
+void sqlite3DequoteExpr(sqlite3 *db, Expr *p){
+if( ExprHasAnyProperty(p, EP_Dequoted) ){
+return;
+}
+ExprSetProperty(p, EP_Dequoted);
+if( p->token.dyn==0 ){
+sqlite3TokenCopy(db, &p->token, &p->token);
+}
+sqlite3Dequote((char*)p->token.z);
+}
+/*
+** The following group of routines make deep copies of expressions,
+** expression lists, ID lists, and select statements.  The copies can
+** be deleted (by being passed to their respective ...Delete() routines)
+** without effecting the originals.
+**
+** The expression list, ID, and source lists return by sqlite3ExprListDup(),
+** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
+** by subsequent calls to sqlite*ListAppend() routines.
+**
+** Any tables that the SrcList might point to are not duplicated.
+*/
+Expr *sqlite3ExprDup(sqlite3 *db, Expr *p){
+Expr *pNew;
+if( p==0 ) return 0;
+pNew = (Expr*)sqlite3DbMallocRaw(db, sizeof(*p) );
+if( pNew==0 ) return 0;
+memcpy(pNew, p, sizeof(*pNew));
+if( p->token.z!=0 ){
+pNew->token.z = (u8*)sqlite3DbStrNDup(db, (char*)p->token.z, p->token.n);
+pNew->token.dyn = 1;
+}else{
+assert( pNew->token.z==0 );
+}
+pNew->span.z = 0;
+pNew->pLeft = sqlite3ExprDup(db, p->pLeft);
+pNew->pRight = sqlite3ExprDup(db, p->pRight);
+pNew->pList = sqlite3ExprListDup(db, p->pList);
+pNew->pSelect = sqlite3SelectDup(db, p->pSelect);
+return pNew;
+}
+void sqlite3TokenCopy(sqlite3 *db, Token *pTo, Token *pFrom){
+if( pTo->dyn ) sqlite3_free((char*)pTo->z);
+if( pFrom->z ){
+pTo->n = pFrom->n;
+pTo->z = (u8*)sqlite3DbStrNDup(db, (char*)pFrom->z, pFrom->n);
+pTo->dyn = 1;
+}else{
+pTo->z = 0;
+}
+}
+ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p){
+ExprList *pNew;
+ExprList::ExprList_item *pItem, *pOldItem;
+int i;
+if( p==0 ) return 0;
+pNew = (ExprList*)sqlite3DbMallocRaw(db, sizeof(*pNew) );
+if( pNew==0 ) return 0;
+pNew->iECursor = 0;
+pNew->nExpr = pNew->nAlloc = p->nExpr;
+pNew->a = pItem = (ExprList::ExprList_item*)sqlite3DbMallocRaw(db,  p->nExpr*sizeof(p->a[0]) );
+if( pItem==0 ){
+sqlite3_free(pNew);
+return 0;
+}
+pOldItem = p->a;
+for(i=0; i<p->nExpr; i++, pItem++, pOldItem++){
+Expr *pNewExpr, *pOldExpr;
+pItem->pExpr = pNewExpr = sqlite3ExprDup(db, pOldExpr = pOldItem->pExpr);
+if( pOldExpr->span.z!=0 && pNewExpr ){
+/* Always make a copy of the span for top-level expressions in the
+** expression list.  The logic in SELECT processing that determines
+** the names of columns in the result set needs this information */
+sqlite3TokenCopy(db, &pNewExpr->span, &pOldExpr->span);
+}
+assert( pNewExpr==0 || pNewExpr->span.z!=0
+|| pOldExpr->span.z==0
+|| db->mallocFailed );
+pItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+pItem->sortOrder = pOldItem->sortOrder;
+pItem->isAgg = pOldItem->isAgg;
+pItem->done = 0;
+}
+return pNew;
+}
+/*
+** If cursors, triggers, views and subqueries are all omitted from
+** the build, then none of the following routines, except for
+** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
+** called with a NULL argument.
+*/
+#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
+|| !defined(SQLITE_OMIT_SUBQUERY)
+SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p){
+SrcList *pNew;
+int i;
+int nByte;
+if( p==0 ) return 0;
+nByte = sizeof(*p) + (p->nSrc>0 ? sizeof(p->a[0]) * (p->nSrc-1) : 0);
+pNew = (SrcList*)sqlite3DbMallocRaw(db, nByte );
+if( pNew==0 ) return 0;
+pNew->nSrc = pNew->nAlloc = p->nSrc;
+for(i=0; i<p->nSrc; i++){
+	  SrcList::SrcList_item *pNewItem = &pNew->a[i];
+	  SrcList::SrcList_item *pOldItem = &p->a[i];
+Table *pTab;
+pNewItem->zDatabase = sqlite3DbStrDup(db, pOldItem->zDatabase);
+pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
+pNewItem->jointype = pOldItem->jointype;
+pNewItem->iCursor = pOldItem->iCursor;
+pNewItem->isPopulated = pOldItem->isPopulated;
+pTab = pNewItem->pTab = pOldItem->pTab;
+if( pTab ){
+pTab->nRef++;
+}
+pNewItem->pSelect = sqlite3SelectDup(db, pOldItem->pSelect);
+pNewItem->pOn = sqlite3ExprDup(db, pOldItem->pOn);
+pNewItem->pUsing = sqlite3IdListDup(db, pOldItem->pUsing);
+pNewItem->colUsed = pOldItem->colUsed;
+}
+return pNew;
+}
+IdList *sqlite3IdListDup(sqlite3 *db, IdList *p){
+IdList *pNew;
+int i;
+if( p==0 ) return 0;
+pNew = (IdList*)sqlite3DbMallocRaw(db, sizeof(*pNew) );
+if( pNew==0 ) return 0;
+pNew->nId = pNew->nAlloc = p->nId;
+pNew->a = (IdList::IdList_item*)sqlite3DbMallocRaw(db, p->nId*sizeof(p->a[0]) );
+if( pNew->a==0 ){
+sqlite3_free(pNew);
+return 0;
+}
+for(i=0; i<p->nId; i++){
+	  IdList::IdList_item *pNewItem = &pNew->a[i];
+	  IdList::IdList_item *pOldItem = &p->a[i];
+pNewItem->zName = sqlite3DbStrDup(db, pOldItem->zName);
+pNewItem->idx = pOldItem->idx;
+}
+return pNew;
+}
+Select *sqlite3SelectDup(sqlite3 *db, Select *p){
+Select *pNew;
+if( p==0 ) return 0;
+pNew = (Select*)sqlite3DbMallocRaw(db, sizeof(*p) );
+if( pNew==0 ) return 0;
+pNew->isDistinct = p->isDistinct;
+pNew->pEList = sqlite3ExprListDup(db, p->pEList);
+pNew->pSrc = sqlite3SrcListDup(db, p->pSrc);
+pNew->pWhere = sqlite3ExprDup(db, p->pWhere);
+pNew->pGroupBy = sqlite3ExprListDup(db, p->pGroupBy);
+pNew->pHaving = sqlite3ExprDup(db, p->pHaving);
+pNew->pOrderBy = sqlite3ExprListDup(db, p->pOrderBy);
+pNew->op = p->op;
+pNew->pPrior = sqlite3SelectDup(db, p->pPrior);
+pNew->pLimit = sqlite3ExprDup(db, p->pLimit);
+pNew->pOffset = sqlite3ExprDup(db, p->pOffset);
+pNew->iLimit = -1;
+pNew->iOffset = -1;
+pNew->isResolved = p->isResolved;
+pNew->isAgg = p->isAgg;
+pNew->usesEphm = 0;
+pNew->disallowOrderBy = 0;
+pNew->pRightmost = 0;
+pNew->addrOpenEphm[0] = -1;
+pNew->addrOpenEphm[1] = -1;
+pNew->addrOpenEphm[2] = -1;
+return pNew;
+}
+#else
+Select *sqlite3SelectDup(sqlite3 *db, Select *p){
+assert( p==0 );
+return 0;
+}
+#endif
+/*
+** Add a new element to the end of an expression list.  If pList is
+** initially NULL, then create a new expression list.
+*/
+ExprList *sqlite3ExprListAppend(
+Parse *pParse,          /* Parsing context */
+ExprList *pList,        /* List to which to append. Might be NULL */
+Expr *pExpr,            /* Expression to be appended */
+Token *pName            /* AS keyword for the expression */
+){
+sqlite3 *db = pParse->db;
+if( pList==0 ){
+pList = (ExprList*)sqlite3DbMallocZero(db, sizeof(ExprList) );
+if( pList==0 ){
+goto no_mem;
+}
+assert( pList->nAlloc==0 );
+}
+if( pList->nAlloc<=pList->nExpr ){
+	  ExprList::ExprList_item *a;
+int n = pList->nAlloc*2 + 4;
+	a = (ExprList::ExprList_item*)sqlite3DbRealloc(db, pList->a, n*sizeof(pList->a[0]));
+if( a==0 ){
+goto no_mem;
+}
+pList->a = a;
+pList->nAlloc = n;
+}
+assert( pList->a!=0 );
+if( pExpr || pName ){
+	  ExprList::ExprList_item *pItem = &pList->a[pList->nExpr++];
+memset(pItem, 0, sizeof(*pItem));
+pItem->zName = sqlite3NameFromToken(db, pName);
+pItem->pExpr = pExpr;
+}
+return pList;
+no_mem:
+/* Avoid leaking memory if malloc has failed. */
+sqlite3ExprDelete(pExpr);
+sqlite3ExprListDelete(pList);
+return 0;
+}
+/*
+** If the expression list pEList contains more than iLimit elements,
+** leave an error message in pParse.
+*/
+void sqlite3ExprListCheckLength(
+Parse *pParse,
+ExprList *pEList,
+int iLimit,
+const char *zObject
+){
+if( pEList && pEList->nExpr>iLimit ){
+sqlite3ErrorMsg(pParse, "too many columns in %s", zObject);
+}
+}
+#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
+/* The following three functions, heightOfExpr(), heightOfExprList()
+** and heightOfSelect(), are used to determine the maximum height
+** of any expression tree referenced by the structure passed as the
+** first argument.
+**
+** If this maximum height is greater than the current value pointed
+** to by pnHeight, the second parameter, then set *pnHeight to that
+** value.
+*/
+static void heightOfExpr(Expr *p, int *pnHeight){
+if( p ){
+if( p->nHeight>*pnHeight ){
+*pnHeight = p->nHeight;
+}
+}
+}
+static void heightOfExprList(ExprList *p, int *pnHeight){
+if( p ){
+int i;
+for(i=0; i<p->nExpr; i++){
+heightOfExpr(p->a[i].pExpr, pnHeight);
+}
+}
+}
+static void heightOfSelect(Select *p, int *pnHeight){
+if( p ){
+heightOfExpr(p->pWhere, pnHeight);
+heightOfExpr(p->pHaving, pnHeight);
+heightOfExpr(p->pLimit, pnHeight);
+heightOfExpr(p->pOffset, pnHeight);
+heightOfExprList(p->pEList, pnHeight);
+heightOfExprList(p->pGroupBy, pnHeight);
+heightOfExprList(p->pOrderBy, pnHeight);
+heightOfSelect(p->pPrior, pnHeight);
+}
+}
+/*
+** Set the Expr.nHeight variable in the structure passed as an
+** argument. An expression with no children, Expr.pList or
+** Expr.pSelect member has a height of 1. Any other expression
+** has a height equal to the maximum height of any other
+** referenced Expr plus one.
+*/
+void sqlite3ExprSetHeight(Expr *p){
+int nHeight = 0;
+heightOfExpr(p->pLeft, &nHeight);
+heightOfExpr(p->pRight, &nHeight);
+heightOfExprList(p->pList, &nHeight);
+heightOfSelect(p->pSelect, &nHeight);
+p->nHeight = nHeight + 1;
+}
+/*
+** Return the maximum height of any expression tree referenced
+** by the select statement passed as an argument.
+*/
+int sqlite3SelectExprHeight(Select *p){
+int nHeight = 0;
+heightOfSelect(p, &nHeight);
+return nHeight;
+}
+#endif
+/*
+** Delete an entire expression list.
+*/
+void sqlite3ExprListDelete(ExprList *pList){
+int i;
+ExprList::ExprList_item *pItem;
+if( pList==0 ) return;
+assert( pList->a!=0 || (pList->nExpr==0 && pList->nAlloc==0) );
+assert( pList->nExpr<=pList->nAlloc );
+for(pItem=pList->a, i=0; i<pList->nExpr; i++, pItem++){
+sqlite3ExprDelete(pItem->pExpr);
+sqlite3_free(pItem->zName);
+}
+sqlite3_free(pList->a);
+sqlite3_free(pList);
+}
+/*
+** Walk an expression tree.  Call xFunc for each node visited.
+**
+** The return value from xFunc determines whether the tree walk continues.
+** 0 means continue walking the tree.  1 means do not walk children
+** of the current node but continue with siblings.  2 means abandon
+** the tree walk completely.
+**
+** The return value from this routine is 1 to abandon the tree walk
+** and 0 to continue.
+**
+** NOTICE:  This routine does *not* descend into subqueries.
+*/
+static int walkExprList(ExprList *, int (*)(void *, Expr*), void *);
+static int walkExprTree(Expr *pExpr, int (*xFunc)(void*,Expr*), void *pArg){
+int rc;
+if( pExpr==0 ) return 0;
+rc = (*xFunc)(pArg, pExpr);
+if( rc==0 ){
+if( walkExprTree(pExpr->pLeft, xFunc, pArg) ) return 1;
+if( walkExprTree(pExpr->pRight, xFunc, pArg) ) return 1;
+if( walkExprList(pExpr->pList, xFunc, pArg) ) return 1;
+}
+return rc>1;
+}
+/*
+** Call walkExprTree() for every expression in list p.
+*/
+static int walkExprList(ExprList *p, int (*xFunc)(void *, Expr*), void *pArg){
+int i;
+ExprList::ExprList_item *pItem;
+if( !p ) return 0;
+for(i=p->nExpr, pItem=p->a; i>0; i--, pItem++){
+if( walkExprTree(pItem->pExpr, xFunc, pArg) ) return 1;
+}
+return 0;
+}
+/*
+** Call walkExprTree() for every expression in Select p, not including
+** expressions that are part of sub-selects in any FROM clause or the LIMIT
+** or OFFSET expressions..
+*/
+static int walkSelectExpr(Select *p, int (*xFunc)(void *, Expr*), void *pArg){
+walkExprList(p->pEList, xFunc, pArg);
+walkExprTree(p->pWhere, xFunc, pArg);
+walkExprList(p->pGroupBy, xFunc, pArg);
+walkExprTree(p->pHaving, xFunc, pArg);
+walkExprList(p->pOrderBy, xFunc, pArg);
+if( p->pPrior ){
+walkSelectExpr(p->pPrior, xFunc, pArg);
+}
+return 0;
+}
+/*
+** This routine is designed as an xFunc for walkExprTree().
+**
+** pArg is really a pointer to an integer.  If we can tell by looking
+** at pExpr that the expression that contains pExpr is not a constant
+** expression, then set *pArg to 0 and return 2 to abandon the tree walk.
+** If pExpr does does not disqualify the expression from being a constant
+** then do nothing.
+**
+** After walking the whole tree, if no nodes are found that disqualify
+** the expression as constant, then we assume the whole expression
+** is constant.  See sqlite3ExprIsConstant() for additional information.
+*/
+static int exprNodeIsConstant(void *pArg, Expr *pExpr){
+int *pN = (int*)pArg;
+/* If *pArg is 3 then any term of the expression that comes from
+** the ON or USING clauses of a join disqualifies the expression
+** from being considered constant. */
+if( (*pN)==3 && ExprHasAnyProperty(pExpr, EP_FromJoin) ){
+*pN = 0;
+return 2;
+}
+switch( pExpr->op ){
+/* Consider functions to be constant if all their arguments are constant
+** and *pArg==2 */
+case TK_FUNCTION:
+if( (*pN)==2 ) return 0;
+/* Fall through */
+case TK_ID:
+case TK_COLUMN:
+case TK_DOT:
+case TK_AGG_FUNCTION:
+case TK_AGG_COLUMN:
+#ifndef SQLITE_OMIT_SUBQUERY
+case TK_SELECT:
+case TK_EXISTS:
+#endif
+*pN = 0;
+return 2;
+case TK_IN:
+if( pExpr->pSelect ){
+*pN = 0;
+return 2;
+}
+default:
+return 0;
+}
+}
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** and 0 if it involves variables or function calls.
+**
+** For the purposes of this function, a double-quoted string (ex: "abc")
+** is considered a variable but a single-quoted string (ex: 'abc') is
+** a constant.
+*/
+int sqlite3ExprIsConstant(Expr *p){
+int isConst = 1;
+walkExprTree(p, exprNodeIsConstant, &isConst);
+return isConst;
+}
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** that does no originate from the ON or USING clauses of a join.
+** Return 0 if it involves variables or function calls or terms from
+** an ON or USING clause.
+*/
+int sqlite3ExprIsConstantNotJoin(Expr *p){
+int isConst = 3;
+walkExprTree(p, exprNodeIsConstant, &isConst);
+return isConst!=0;
+}
+/*
+** Walk an expression tree.  Return 1 if the expression is constant
+** or a function call with constant arguments.  Return and 0 if there
+** are any variables.
+**
+** For the purposes of this function, a double-quoted string (ex: "abc")
+** is considered a variable but a single-quoted string (ex: 'abc') is
+** a constant.
+*/
+int sqlite3ExprIsConstantOrFunction(Expr *p){
+int isConst = 2;
+walkExprTree(p, exprNodeIsConstant, &isConst);
+return isConst!=0;
+}
+/*
+** If the expression p codes a constant integer that is small enough
+** to fit in a 32-bit integer, return 1 and put the value of the integer
+** in *pValue.  If the expression is not an integer or if it is too big
+** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
+*/
+int sqlite3ExprIsInteger(Expr *p, int *pValue){
+switch( p->op ){
+case TK_INTEGER: {
+if( sqlite3GetInt32((char*)p->token.z, pValue) ){
+return 1;
+}
+break;
+}
+case TK_UPLUS: {
+return sqlite3ExprIsInteger(p->pLeft, pValue);
+}
+case TK_UMINUS: {
+int v;
+if( sqlite3ExprIsInteger(p->pLeft, &v) ){
+*pValue = -v;
+return 1;
+}
+break;
+}
+default: break;
+}
+return 0;
+}
+/*
+** Return TRUE if the given string is a row-id column name.
+*/
+int sqlite3IsRowid(const char *z){
+if( sqlite3StrICmp(z, "_ROWID_")==0 ) return 1;
+if( sqlite3StrICmp(z, "ROWID")==0 ) return 1;
+if( sqlite3StrICmp(z, "OID")==0 ) return 1;
+return 0;
+}
+/*
+** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
+** that name in the set of source tables in pSrcList and make the pExpr
+** expression node refer back to that source column.  The following changes
+** are made to pExpr:
+**
+**    pExpr->iDb           Set the index in db->aDb[] of the database holding
+**                         the table.
+**    pExpr->iTable        Set to the cursor number for the table obtained
+**                         from pSrcList.
+**    pExpr->iColumn       Set to the column number within the table.
+**    pExpr->op            Set to TK_COLUMN.
+**    pExpr->pLeft         Any expression this points to is deleted
+**    pExpr->pRight        Any expression this points to is deleted.
+**
+** The pDbToken is the name of the database (the "X").  This value may be
+** NULL meaning that name is of the form Y.Z or Z.  Any available database
+** can be used.  The pTableToken is the name of the table (the "Y").  This
+** value can be NULL if pDbToken is also NULL.  If pTableToken is NULL it
+** means that the form of the name is Z and that columns from any table
+** can be used.
+**
+** If the name cannot be resolved unambiguously, leave an error message
+** in pParse and return non-zero.  Return zero on success.
+*/
+static int lookupName(
+Parse *pParse,       /* The parsing context */
+Token *pDbToken,     /* Name of the database containing table, or NULL */
+Token *pTableToken,  /* Name of table containing column, or NULL */
+Token *pColumnToken, /* Name of the column. */
+NameContext *pNC,    /* The name context used to resolve the name */
+Expr *pExpr          /* Make this EXPR node point to the selected column */
+){
+char *zDb = 0;       /* Name of the database.  The "X" in X.Y.Z */
+char *zTab = 0;      /* Name of the table.  The "Y" in X.Y.Z or Y.Z */
+char *zCol = 0;      /* Name of the column.  The "Z" */
+int i, j;            /* Loop counters */
+int cnt = 0;         /* Number of matching column names */
+int cntTab = 0;      /* Number of matching table names */
+sqlite3 *db = pParse->db;  /* The database */
+SrcList::SrcList_item *pItem;       /* Use for looping over pSrcList items */
+SrcList::SrcList_item *pMatch = 0;  /* The matching pSrcList item */
+NameContext *pTopNC = pNC;        /* First namecontext in the list */
+Schema *pSchema = 0;              /* Schema of the expression */
+assert( pColumnToken && pColumnToken->z ); /* The Z in X.Y.Z cannot be NULL */
+zDb = sqlite3NameFromToken(db, pDbToken);
+zTab = sqlite3NameFromToken(db, pTableToken);
+zCol = sqlite3NameFromToken(db, pColumnToken);
+if( db->mallocFailed ){
+goto lookupname_end;
+}
+pExpr->iTable = -1;
+while( pNC && cnt==0 ){
+ExprList *pEList;
+SrcList *pSrcList = pNC->pSrcList;
+if( pSrcList ){
+for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
+Table *pTab;
+int iDb;
+Column *pCol;
+pTab = pItem->pTab;
+assert( pTab!=0 );
+iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+assert( pTab->nCol>0 );
+if( zTab ){
+if( pItem->zAlias ){
+char *zTabName = pItem->zAlias;
+if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
+}else{
+char *zTabName = pTab->zName;
+if( zTabName==0 || sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
+if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
+continue;
+}
+}
+}
+if( 0==(cntTab++) ){
+pExpr->iTable = pItem->iCursor;
+pSchema = pTab->pSchema;
+pMatch = pItem;
+}
+for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
+if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+const char *zColl = pTab->aCol[j].zColl;
+IdList *pUsing;
+cnt++;
+pExpr->iTable = pItem->iCursor;
+pMatch = pItem;
+pSchema = pTab->pSchema;
+/* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
+pExpr->iColumn = j==pTab->iPKey ? -1 : j;
+pExpr->affinity = pTab->aCol[j].affinity;
+if( (pExpr->flags & EP_ExpCollate)==0 ){
+pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+}
+if( i<pSrcList->nSrc-1 ){
+if( pItem[1].jointype & JT_NATURAL ){
+/* If this match occurred in the left table of a natural join,
+** then skip the right table to avoid a duplicate match */
+pItem++;
+i++;
+}else if( (pUsing = pItem[1].pUsing)!=0 ){
+/* If this match occurs on a column that is in the USING clause
+** of a join, skip the search of the right table of the join
+** to avoid a duplicate match there. */
+int k;
+for(k=0; k<pUsing->nId; k++){
+if( sqlite3StrICmp(pUsing->a[k].zName, zCol)==0 ){
+pItem++;
+i++;
+break;
+}
+}
+}
+}
+break;
+}
+}
+}
+}
+#ifndef SQLITE_OMIT_TRIGGER
+/* If we have not already resolved the name, then maybe
+** it is a new.* or old.* trigger argument reference
+*/
+if( zDb==0 && zTab!=0 && cnt==0 && pParse->trigStack!=0 ){
+TriggerStack *pTriggerStack = pParse->trigStack;
+Table *pTab = 0;
+if( pTriggerStack->newIdx != -1 && sqlite3StrICmp("new", zTab) == 0 ){
+pExpr->iTable = pTriggerStack->newIdx;
+assert( pTriggerStack->pTab );
+pTab = pTriggerStack->pTab;
+}else if( pTriggerStack->oldIdx != -1 && sqlite3StrICmp("old", zTab)==0 ){
+pExpr->iTable = pTriggerStack->oldIdx;
+assert( pTriggerStack->pTab );
+pTab = pTriggerStack->pTab;
+}
+if( pTab ){
+int iCol;
+Column *pCol = pTab->aCol;
+pSchema = pTab->pSchema;
+cntTab++;
+for(iCol=0; iCol < pTab->nCol; iCol++, pCol++) {
+if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
+const char *zColl = pTab->aCol[iCol].zColl;
+cnt++;
+pExpr->iColumn = iCol==pTab->iPKey ? -1 : iCol;
+pExpr->affinity = pTab->aCol[iCol].affinity;
+if( (pExpr->flags & EP_ExpCollate)==0 ){
+pExpr->pColl = sqlite3FindCollSeq(db, ENC(db), zColl,-1, 0);
+}
+pExpr->pTab = pTab;
+break;
+}
+}
+}
+}
+#endif /* !defined(SQLITE_OMIT_TRIGGER) */
+/*
+** Perhaps the name is a reference to the ROWID
+*/
+if( cnt==0 && cntTab==1 && sqlite3IsRowid(zCol) ){
+cnt = 1;
+pExpr->iColumn = -1;
+pExpr->affinity = SQLITE_AFF_INTEGER;
+}
+/*
+** If the input is of the form Z (not Y.Z or X.Y.Z) then the name Z
+** might refer to an result-set alias.  This happens, for example, when
+** we are resolving names in the WHERE clause of the following command:
+**
+**     SELECT a+b AS x FROM table WHERE x<10;
+**
+** In cases like this, replace pExpr with a copy of the expression that
+** forms the result set entry ("a+b" in the example) and return immediately.
+** Note that the expression in the result set should have already been
+** resolved by the time the WHERE clause is resolved.
+*/
+if( cnt==0 && (pEList = pNC->pEList)!=0 && zTab==0 ){
+for(j=0; j<pEList->nExpr; j++){
+char *zAs = pEList->a[j].zName;
+if( zAs!=0 && sqlite3StrICmp(zAs, zCol)==0 ){
+Expr *pDup, *pOrig;
+assert( pExpr->pLeft==0 && pExpr->pRight==0 );
+assert( pExpr->pList==0 );
+assert( pExpr->pSelect==0 );
+pOrig = pEList->a[j].pExpr;
+if( !pNC->allowAgg && ExprHasProperty(pOrig, EP_Agg) ){
+sqlite3ErrorMsg(pParse, "misuse of aliased aggregate %s", zAs);
+sqlite3_free(zCol);
+return 2;
+}
+pDup = sqlite3ExprDup(db, pOrig);
+if( pExpr->flags & EP_ExpCollate ){
+pDup->pColl = pExpr->pColl;
+pDup->flags |= EP_ExpCollate;
+}
+if( pExpr->span.dyn ) sqlite3_free((char*)pExpr->span.z);
+if( pExpr->token.dyn ) sqlite3_free((char*)pExpr->token.z);
+memcpy(pExpr, pDup, sizeof(*pExpr));
+sqlite3_free(pDup);
+cnt = 1;
+pMatch = 0;
+assert( zTab==0 && zDb==0 );
+goto lookupname_end_2;
+}
+}
+}
+/* Advance to the next name context.  The loop will exit when either
+** we have a match (cnt>0) or when we run out of name contexts.
+*/
+if( cnt==0 ){
+pNC = pNC->pNext;
+}
+}
+/*
+** If X and Y are NULL (in other words if only the column name Z is
+** supplied) and the value of Z is enclosed in double-quotes, then
+** Z is a string literal if it doesn't match any column names.  In that
+** case, we need to return right away and not make any changes to
+** pExpr.
+**
+** Because no reference was made to outer contexts, the pNC->nRef
+** fields are not changed in any context.
+*/
+if( cnt==0 && zTab==0 && pColumnToken->z[0]=='"' ){
+sqlite3_free(zCol);
+return 0;
+}
+/*
+** cnt==0 means there was not match.  cnt>1 means there were two or
+** more matches.  Either way, we have an error.
+*/
+if( cnt!=1 ){
+char *z = 0;
+char *zErr;
+zErr = (char*)(cnt==0 ? "no such column: %s" : "ambiguous column name: %s");
+if( zDb ){
+sqlite3SetString(&z, zDb, ".", zTab, ".", zCol, (char*)0);
+}else if( zTab ){
+sqlite3SetString(&z, zTab, ".", zCol, (char*)0);
+}else{
+z = sqlite3StrDup(zCol);
+}
+if( z ){
+sqlite3ErrorMsg(pParse, zErr, z);
+sqlite3_free(z);
+pTopNC->nErr++;
+}else{
+db->mallocFailed = 1;
+}
+}
+/* If a column from a table in pSrcList is referenced, then record
+** this fact in the pSrcList.a[].colUsed bitmask.  Column 0 causes
+** bit 0 to be set.  Column 1 sets bit 1.  And so forth.  If the
+** column number is greater than the number of bits in the bitmask
+** then set the high-order bit of the bitmask.
+*/
+if( pExpr->iColumn>=0 && pMatch!=0 ){
+int n = pExpr->iColumn;
+if( n>=sizeof(Bitmask)*8 ){
+n = sizeof(Bitmask)*8-1;
+}
+assert( pMatch->iCursor==pExpr->iTable );
+pMatch->colUsed |= ((Bitmask)1)<<n;
+}
+lookupname_end:
+/* Clean up and return
+*/
+sqlite3_free(zDb);
+sqlite3_free(zTab);
+sqlite3ExprDelete(pExpr->pLeft);
+pExpr->pLeft = 0;
+sqlite3ExprDelete(pExpr->pRight);
+pExpr->pRight = 0;
+pExpr->op = TK_COLUMN;
+lookupname_end_2:
+sqlite3_free(zCol);
+if( cnt==1 ){
+assert( pNC!=0 );
+sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList);
+if( pMatch && !pMatch->pSelect ){
+pExpr->pTab = pMatch->pTab;
+}
+/* Increment the nRef value on all name contexts from TopNC up to
+** the point where the name matched. */
+for(;;){
+assert( pTopNC!=0 );
+pTopNC->nRef++;
+if( pTopNC==pNC ) break;
+pTopNC = pTopNC->pNext;
+}
+return 0;
+} else {
+return 1;
+}
+}
+/*
+** This routine is designed as an xFunc for walkExprTree().
+**
+** Resolve symbolic names into TK_COLUMN operators for the current
+** node in the expression tree.  Return 0 to continue the search down
+** the tree or 2 to abort the tree walk.
+**
+** This routine also does error checking and name resolution for
+** function names.  The operator for aggregate functions is changed
+** to TK_AGG_FUNCTION.
+*/
+static int nameResolverStep(void *pArg, Expr *pExpr){
+NameContext *pNC = (NameContext*)pArg;
+Parse *pParse;
+if( pExpr==0 ) return 1;
+assert( pNC!=0 );
+pParse = pNC->pParse;
+if( ExprHasAnyProperty(pExpr, EP_Resolved) ) return 1;
+ExprSetProperty(pExpr, EP_Resolved);
+#ifndef NDEBUG
+if( pNC->pSrcList && pNC->pSrcList->nAlloc>0 ){
+SrcList *pSrcList = pNC->pSrcList;
+int i;
+for(i=0; i<pNC->pSrcList->nSrc; i++){
+assert( pSrcList->a[i].iCursor>=0 && pSrcList->a[i].iCursor<pParse->nTab);
+}
+}
+#endif
+switch( pExpr->op ){
+/* Double-quoted strings (ex: "abc") are used as identifiers if
+** possible.  Otherwise they remain as strings.  Single-quoted
+** strings (ex: 'abc') are always string literals.
+*/
+case TK_STRING: {
+if( pExpr->token.z[0]=='\'' ) break;
+/* Fall thru into the TK_ID case if this is a double-quoted string */
+}
+/* A lone identifier is the name of a column.
+*/
+case TK_ID: {
+lookupName(pParse, 0, 0, &pExpr->token, pNC, pExpr);
+return 1;
+}
+/* A table name and column name:     ID.ID
+** Or a database, table and column:  ID.ID.ID
+*/
+case TK_DOT: {
+Token *pColumn;
+Token *pTable;
+Token *pDb;
+Expr *pRight;
+/* if( pSrcList==0 ) break; */
+pRight = pExpr->pRight;
+if( pRight->op==TK_ID ){
+pDb = 0;
+pTable = &pExpr->pLeft->token;
+pColumn = &pRight->token;
+}else{
+assert( pRight->op==TK_DOT );
+pDb = &pExpr->pLeft->token;
+pTable = &pRight->pLeft->token;
+pColumn = &pRight->pRight->token;
+}
+lookupName(pParse, pDb, pTable, pColumn, pNC, pExpr);
+return 1;
+}
+/* Resolve function names
+*/
+case TK_CONST_FUNC:
+case TK_FUNCTION: {
+ExprList *pList = pExpr->pList;    /* The argument list */
+int n = pList ? pList->nExpr : 0;  /* Number of arguments */
+int no_such_func = 0;       /* True if no such function exists */
+int wrong_num_args = 0;     /* True if wrong number of arguments */
+int is_agg = 0;             /* True if is an aggregate function */
+int i;
+int auth;                   /* Authorization to use the function */
+int nId;                    /* Number of characters in function name */
+const char *zId;            /* The function name. */
+FuncDef *pDef;              /* Information about the function */
+int enc = ENC(pParse->db);  /* The database encoding */
+zId = (char*)pExpr->token.z;
+nId = pExpr->token.n;
+pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
+if( pDef==0 ){
+pDef = sqlite3FindFunction(pParse->db, zId, nId, -1, enc, 0);
+if( pDef==0 ){
+no_such_func = 1;
+}else{
+wrong_num_args = 1;
+}
+}else{
+is_agg = pDef->xFunc==0;
+}
+#ifndef SQLITE_OMIT_AUTHORIZATION
+if( pDef ){
+auth = sqlite3AuthCheck(pParse, SQLITE_FUNCTION, 0, pDef->zName, 0);
+if( auth!=SQLITE_OK ){
+if( auth==SQLITE_DENY ){
+sqlite3ErrorMsg(pParse, "not authorized to use function: %s",
+pDef->zName);
+pNC->nErr++;
+}
+pExpr->op = TK_NULL;
+return 1;
+}
+}
+#endif
+if( is_agg && !pNC->allowAgg ){
+sqlite3ErrorMsg(pParse, "misuse of aggregate function %.*s()", nId,zId);
+pNC->nErr++;
+is_agg = 0;
+}else if( no_such_func ){
+sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
+pNC->nErr++;
+}else if( wrong_num_args ){
+sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
+nId, zId);
+pNC->nErr++;
+}
+if( is_agg ){
+pExpr->op = TK_AGG_FUNCTION;
+pNC->hasAgg = 1;
+}
+if( is_agg ) pNC->allowAgg = 0;
+for(i=0; pNC->nErr==0 && i<n; i++){
+walkExprTree(pList->a[i].pExpr, nameResolverStep, pNC);
+}
+if( is_agg ) pNC->allowAgg = 1;
+/* FIX ME:  Compute pExpr->affinity based on the expected return
+** type of the function
+*/
+return is_agg;
+}
+#ifndef SQLITE_OMIT_SUBQUERY
+case TK_SELECT:
+case TK_EXISTS:
+#endif
+case TK_IN: {
+if( pExpr->pSelect ){
+int nRef = pNC->nRef;
+#ifndef SQLITE_OMIT_CHECK
+if( pNC->isCheck ){
+sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
+}
+#endif
+sqlite3SelectResolve(pParse, pExpr->pSelect, pNC);
+assert( pNC->nRef>=nRef );
+if( nRef!=pNC->nRef ){
+ExprSetProperty(pExpr, EP_VarSelect);
+}
+}
+break;
+}
+#ifndef SQLITE_OMIT_CHECK
+case TK_VARIABLE: {
+if( pNC->isCheck ){
+sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
+}
+break;
+}
+#endif
+}
+return 0;
+}
+/*
+** This routine walks an expression tree and resolves references to
+** table columns.  Nodes of the form ID.ID or ID resolve into an
+** index to the table in the table list and a column offset.  The
+** Expr.opcode for such nodes is changed to TK_COLUMN.  The Expr.iTable
+** value is changed to the index of the referenced table in pTabList
+** plus the "base" value.  The base value will ultimately become the
+** VDBE cursor number for a cursor that is pointing into the referenced
+** table.  The Expr.iColumn value is changed to the index of the column
+** of the referenced table.  The Expr.iColumn value for the special
+** ROWID column is -1.  Any INTEGER PRIMARY KEY column is tried as an
+** alias for ROWID.
+**
+** Also resolve function names and check the functions for proper
+** usage.  Make sure all function names are recognized and all functions
+** have the correct number of arguments.  Leave an error message
+** in pParse->zErrMsg if anything is amiss.  Return the number of errors.
+**
+** If the expression contains aggregate functions then set the EP_Agg
+** property on the expression.
+*/
+int sqlite3ExprResolveNames(
+NameContext *pNC,       /* Namespace to resolve expressions in. */
+Expr *pExpr             /* The expression to be analyzed. */
+){
+int savedHasAgg;
+if( pExpr==0 ) return 0;
+#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
+if( (pExpr->nHeight+pNC->pParse->nHeight)>SQLITE_MAX_EXPR_DEPTH ){
+sqlite3ErrorMsg(pNC->pParse,
+"Expression tree is too large (maximum depth %d)",
+SQLITE_MAX_EXPR_DEPTH
+);
+return 1;
+}
+pNC->pParse->nHeight += pExpr->nHeight;
+#endif
+savedHasAgg = pNC->hasAgg;
+pNC->hasAgg = 0;
+walkExprTree(pExpr, nameResolverStep, pNC);
+#if defined(SQLITE_TEST) || SQLITE_MAX_EXPR_DEPTH>0
+pNC->pParse->nHeight -= pExpr->nHeight;
+#endif
+if( pNC->nErr>0 ){
+ExprSetProperty(pExpr, EP_Error);
+}
+if( pNC->hasAgg ){
+ExprSetProperty(pExpr, EP_Agg);
+}else if( savedHasAgg ){
+pNC->hasAgg = 1;
+}
+return ExprHasProperty(pExpr, EP_Error);
+}
+/*
+** A pointer instance of this structure is used to pass information
+** through walkExprTree into codeSubqueryStep().
+*/
+typedef struct QueryCoder QueryCoder;
+struct QueryCoder {
+Parse *pParse;       /* The parsing context */
+NameContext *pNC;    /* Namespace of first enclosing query */
+};
+#ifdef SQLITE_TEST
+int sqlite3_enable_in_opt = 1;
+#else
+#define sqlite3_enable_in_opt 1
+#endif
+/*
+** This function is used by the implementation of the IN (...) operator.
+** It's job is to find or create a b-tree structure that may be used
+** either to test for membership of the (...) set or to iterate through
+** its members, skipping duplicates.
+**
+** The cursor opened on the structure (database table, database index
+** or ephermal table) is stored in pX->iTable before this function returns.
+** The returned value indicates the structure type, as follows:
+**
+**   IN_INDEX_ROWID - The cursor was opened on a database table.
+**   IN_INDEX_INDEX - The cursor was opened on a database indec.
+**   IN_INDEX_EPH -   The cursor was opened on a specially created and
+**                    populated epheremal table.
+**
+** An existing structure may only be used if the SELECT is of the simple
+** form:
+**
+**     SELECT <column> FROM <table>
+**
+** If the mustBeUnique parameter is false, the structure will be used
+** for fast set membership tests. In this case an epheremal table must
+** be used unless <column> is an INTEGER PRIMARY KEY or an index can
+** be found with <column> as its left-most column.
+**
+** If mustBeUnique is true, then the structure will be used to iterate
+** through the set members, skipping any duplicates. In this case an
+** epheremal table must be used unless the selected <column> is guaranteed
+** to be unique - either because it is an INTEGER PRIMARY KEY or it
+** is unique by virtue of a constraint or implicit index.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+int sqlite3FindInIndex(Parse *pParse, Expr *pX, int mustBeUnique){
+Select *p;
+int eType = 0;
+int iTab = pParse->nTab++;
+/* The follwing if(...) expression is true if the SELECT is of the
+** simple form:
+**
+**     SELECT <column> FROM <table>
+**
+** If this is the case, it may be possible to use an existing table
+** or index instead of generating an epheremal table.
+*/
+if( sqlite3_enable_in_opt
+&& (p=pX->pSelect) && !p->pPrior
+&& !p->isDistinct && !p->isAgg && !p->pGroupBy
+&& p->pSrc && p->pSrc->nSrc==1 && !p->pSrc->a[0].pSelect
+&& !p->pSrc->a[0].pTab->pSelect
+&& p->pEList->nExpr==1 && p->pEList->a[0].pExpr->op==TK_COLUMN
+&& !p->pLimit && !p->pOffset && !p->pWhere
+){
+sqlite3 *db = pParse->db;
+Index *pIdx;
+Expr *pExpr = p->pEList->a[0].pExpr;
+int iCol = pExpr->iColumn;
+Vdbe *v = sqlite3GetVdbe(pParse);
+/* This function is only called from two places. In both cases the vdbe
+** has already been allocated. So assume sqlite3GetVdbe() is always
+** successful here.
+*/
+assert(v);
+if( iCol<0 ){
+int iMem = pParse->nMem++;
+int iAddr;
+Table *pTab = p->pSrc->a[0].pTab;
+int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+sqlite3VdbeUsesBtree(v, iDb);
+sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
+iAddr = sqlite3VdbeAddOp(v, OP_If, 0, iMem);
+sqlite3VdbeAddOp(v, OP_MemInt, 1, iMem);
+sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
+eType = IN_INDEX_ROWID;
+sqlite3VdbeJumpHere(v, iAddr);
+}else{
+/* The collation sequence used by the comparison. If an index is to
+** be used in place of a temp-table, it must be ordered according
+** to this collation sequence.
+*/
+CollSeq *pReq = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pExpr);
+/* Check that the affinity that will be used to perform the
+** comparison is the same as the affinity of the column. If
+** it is not, it is not possible to use any index.
+*/
+Table *pTab = p->pSrc->a[0].pTab;
+char aff = comparisonAffinity(pX);
+int affinity_ok = (pTab->aCol[iCol].affinity==aff||aff==SQLITE_AFF_NONE);
+for(pIdx=pTab->pIndex; pIdx && eType==0 && affinity_ok; pIdx=pIdx->pNext){
+if( (pIdx->aiColumn[0]==iCol)
+&& (pReq==sqlite3FindCollSeq(db, ENC(db), pIdx->azColl[0], -1, 0))
+&& (!mustBeUnique || (pIdx->nColumn==1 && pIdx->onError!=OE_None))
+){
+int iDb;
+int iMem = pParse->nMem++;
+int iAddr;
+char *pKey;
+pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
+iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
+sqlite3VdbeUsesBtree(v, iDb);
+sqlite3VdbeAddOp(v, OP_MemLoad, iMem, 0);
+iAddr = sqlite3VdbeAddOp(v, OP_If, 0, iMem);
+sqlite3VdbeAddOp(v, OP_MemInt, 1, iMem);
+sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
+VdbeComment((v, "# %s", pIdx->zName));
+sqlite3VdbeOp3(v,OP_OpenRead,iTab,pIdx->tnum,pKey,P3_KEYINFO_HANDOFF);
+eType = IN_INDEX_INDEX;
+sqlite3VdbeAddOp(v, OP_SetNumColumns, iTab, pIdx->nColumn);
+sqlite3VdbeJumpHere(v, iAddr);
+}
+}
+}
+}
+if( eType==0 ){
+sqlite3CodeSubselect(pParse, pX);
+eType = IN_INDEX_EPH;
+}else{
+pX->iTable = iTab;
+}
+return eType;
+}
+#endif
+/*
+** Generate code for scalar subqueries used as an expression
+** and IN operators.  Examples:
+**
+**     (SELECT a FROM b)          -- subquery
+**     EXISTS (SELECT a FROM b)   -- EXISTS subquery
+**     x IN (4,5,11)              -- IN operator with list on right-hand side
+**     x IN (SELECT a FROM b)     -- IN operator with subquery on the right
+**
+** The pExpr parameter describes the expression that contains the IN
+** operator or subquery.
+*/
+#ifndef SQLITE_OMIT_SUBQUERY
+void sqlite3CodeSubselect(Parse *pParse, Expr *pExpr){
+int testAddr = 0;                       /* One-time test address */
+Vdbe *v = sqlite3GetVdbe(pParse);
+if( v==0 ) return;
+/* This code must be run in its entirety every time it is encountered
+** if any of the following is true:
+**
+**    *  The right-hand side is a correlated subquery
+**    *  The right-hand side is an expression list containing variables
+**    *  We are inside a trigger
+**
+** If all of the above are false, then we can run this code just once
+** save the results, and reuse the same result on subsequent invocations.
+*/
+if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
+int mem = pParse->nMem++;
+sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
+testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
+assert( testAddr>0 || pParse->db->mallocFailed );
+sqlite3VdbeAddOp(v, OP_MemInt, 1, mem);
+}
+switch( pExpr->op ){
+case TK_IN: {
+char affinity;
+KeyInfo keyInfo;
+int addr;        /* Address of OP_OpenEphemeral instruction */
+affinity = sqlite3ExprAffinity(pExpr->pLeft);
+/* Whether this is an 'x IN(SELECT...)' or an 'x IN(<exprlist>)'
+** expression it is handled the same way. A virtual table is
+** filled with single-field index keys representing the results
+** from the SELECT or the <exprlist>.
+**
+** If the 'x' expression is a column value, or the SELECT...
+** statement returns a column value, then the affinity of that
+** column is used to build the index keys. If both 'x' and the
+** SELECT... statement are columns, then numeric affinity is used
+** if either column has NUMERIC or INTEGER affinity. If neither
+** 'x' nor the SELECT... statement are columns, then numeric affinity
+** is used.
+*/
+pExpr->iTable = pParse->nTab++;
+addr = sqlite3VdbeAddOp(v, OP_OpenEphemeral, pExpr->iTable, 0);
+memset(&keyInfo, 0, sizeof(keyInfo));
+keyInfo.nField = 1;
+sqlite3VdbeAddOp(v, OP_SetNumColumns, pExpr->iTable, 1);
+if( pExpr->pSelect ){
+/* Case 1:     expr IN (SELECT ...)
+**
+** Generate code to write the results of the select into the temporary
+** table allocated and opened above.
+*/
+int iParm = pExpr->iTable +  (((int)affinity)<<16);
+ExprList *pEList;
+assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
+if( sqlite3Select(pParse, pExpr->pSelect, SRT_Set, iParm, 0, 0, 0, 0) ){
+return;
+}
+pEList = pExpr->pSelect->pEList;
+if( pEList && pEList->nExpr>0 ){
+keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
+pEList->a[0].pExpr);
+}
+}else if( pExpr->pList ){
+/* Case 2:     expr IN (exprlist)
+**
+** For each expression, build an index key from the evaluation and
+** store it in the temporary table. If <expr> is a column, then use
+** that columns affinity when building index keys. If <expr> is not
+** a column, use numeric affinity.
+*/
+int i;
+ExprList *pList = pExpr->pList;
+		ExprList::ExprList_item *pItem;
+if( !affinity ){
+affinity = SQLITE_AFF_NONE;
+}
+keyInfo.aColl[0] = pExpr->pLeft->pColl;
+/* Loop through each expression in <exprlist>. */
+for(i=pList->nExpr, pItem=pList->a; i>0; i--, pItem++){
+Expr *pE2 = pItem->pExpr;
+/* If the expression is not constant then we will need to
+** disable the test that was generated above that makes sure
+** this code only executes once.  Because for a non-constant
+** expression we need to rerun this code each time.
+*/
+if( testAddr>0 && !sqlite3ExprIsConstant(pE2) ){
+sqlite3VdbeChangeToNoop(v, testAddr-1, 3);
+testAddr = 0;
+}
+/* Evaluate the expression and insert it into the temp table */
+sqlite3ExprCode(pParse, pE2);
+sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);
+sqlite3VdbeAddOp(v, OP_IdxInsert, pExpr->iTable, 0);
+}
+}
+sqlite3VdbeChangeP3(v, addr, (const char *)&keyInfo, P3_KEYINFO);
+break;
+}
+case TK_EXISTS:
+case TK_SELECT: {
+/* This has to be a scalar SELECT.  Generate code to put the
+** value of this select in a memory cell and record the number
+** of the memory cell in iColumn.
+*/
+static const Token one = { (u8*)"1", 0, 1 };
+Select *pSel;
+int iMem;
+int sop;
+pExpr->iColumn = iMem = pParse->nMem++;
+pSel = pExpr->pSelect;
+if( pExpr->op==TK_SELECT ){
+sop = SRT_Mem;
+sqlite3VdbeAddOp(v, OP_MemNull, iMem, 0);
+VdbeComment((v, "# Init subquery result"));
+}else{
+sop = SRT_Exists;
+sqlite3VdbeAddOp(v, OP_MemInt, 0, iMem);
+VdbeComment((v, "# Init EXISTS result"));
+}
+sqlite3ExprDelete(pSel->pLimit);
+pSel->pLimit = sqlite3PExpr(pParse, TK_INTEGER, 0, 0, &one);
+if( sqlite3Select(pParse, pSel, sop, iMem, 0, 0, 0, 0) ){
+return;
+}
+break;
+}
+}
+if( testAddr ){
+sqlite3VdbeJumpHere(v, testAddr);
+}
+return;
+}
+#endif /* SQLITE_OMIT_SUBQUERY */
+/*
+** Duplicate an 8-byte value
+*/
+static char *dup8bytes(Vdbe *v, const char *in){
+char *out = (char*)sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
+if( out ){
+memcpy(out, in, 8);
+}
+return out;
+}
+/*
+** Generate an instruction that will put the floating point
+** value described by z[0..n-1] on the stack.
+**
+** The z[] string will probably not be zero-terminated.  But the
+** z[n] character is guaranteed to be something that does not look
+** like the continuation of the number.
+*/
+static void codeReal(Vdbe *v, const char *z, int n, int negateFlag){
+assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
+if( z ){
+double value;
+char *zV;
+assert( !isdigit(z[n]) );
+sqlite3AtoF(z, &value);
+if( negateFlag ) value = -value;
+zV = dup8bytes(v, (char*)&value);
+sqlite3VdbeOp3(v, OP_Real, 0, 0, zV, P3_REAL);
+}
+}
+/*
+** Generate an instruction that will put the integer describe by
+** text z[0..n-1] on the stack.
+**
+** The z[] string will probably not be zero-terminated.  But the
+** z[n] character is guaranteed to be something that does not look
+** like the continuation of the number.
+*/
+static void codeInteger(Vdbe *v, const char *z, int n, int negateFlag){
+assert( z || v==0 || sqlite3VdbeDb(v)->mallocFailed );
+if( z ){
+int i;
+assert( !isdigit(z[n]) );
+if( sqlite3GetInt32(z, &i) ){
+if( negateFlag ) i = -i;
+sqlite3VdbeAddOp(v, OP_Integer, i, 0);
+}else if( sqlite3FitsIn64Bits(z, negateFlag) ){
+i64 value;
+char *zV;
+sqlite3Atoi64(z, &value);
+if( negateFlag ) value = -value;
+zV = dup8bytes(v, (char*)&value);
+sqlite3VdbeOp3(v, OP_Int64, 0, 0, zV, P3_INT64);
+}else{
+codeReal(v, z, n, negateFlag);
+}
+}
+}
+/*
+** Generate code that will extract the iColumn-th column from
+** table pTab and push that column value on the stack.  There
+** is an open cursor to pTab in iTable.  If iColumn<0 then
+** code is generated that extracts the rowid.
+*/
+void sqlite3ExprCodeGetColumn(Vdbe *v, Table *pTab, int iColumn, int iTable){
+if( iColumn<0 ){
+int op = (pTab && IsVirtual(pTab)) ? OP_VRowid : OP_Rowid;
+sqlite3VdbeAddOp(v, op, iTable, 0);
+}else if( pTab==0 ){
+sqlite3VdbeAddOp(v, OP_Column, iTable, iColumn);
+}else{
+int op = IsVirtual(pTab) ? OP_VColumn : OP_Column;
+sqlite3VdbeAddOp(v, op, iTable, iColumn);
+sqlite3ColumnDefault(v, pTab, iColumn);
+#ifndef SQLITE_OMIT_FLOATING_POINT
+if( pTab->aCol[iColumn].affinity==SQLITE_AFF_REAL ){
+sqlite3VdbeAddOp(v, OP_RealAffinity, 0, 0);
+}
+#endif
+}
+}
+/*
+** Generate code into the current Vdbe to evaluate the given
+** expression and leave the result on the top of stack.
+**
+** This code depends on the fact that certain token values (ex: TK_EQ)
+** are the same as opcode values (ex: OP_Eq) that implement the corresponding
+** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
+** the make process cause these values to align.  Assert()s in the code
+** below verify that the numbers are aligned correctly.
+*/
+void sqlite3ExprCode(Parse *pParse, Expr *pExpr){
+Vdbe *v = pParse->pVdbe;
+int op;
+int stackChng = 1;    /* Amount of change to stack depth */
+if( v==0 ) return;
+if( pExpr==0 ){
+sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+return;
+}
+op = pExpr->op;
+switch( op ){
+case TK_AGG_COLUMN: {
+AggInfo *pAggInfo = pExpr->pAggInfo;
+	  AggInfo::AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
+if( !pAggInfo->directMode ){
+sqlite3VdbeAddOp(v, OP_MemLoad, pCol->iMem, 0);
+break;
+}else if( pAggInfo->useSortingIdx ){
+sqlite3VdbeAddOp(v, OP_Column, pAggInfo->sortingIdx,
+pCol->iSorterColumn);
+break;
+}
+/* Otherwise, fall thru into the TK_COLUMN case */
+}
+case TK_COLUMN: {
+if( pExpr->iTable<0 ){
+/* This only happens when coding check constraints */
+assert( pParse->ckOffset>0 );
+sqlite3VdbeAddOp(v, OP_Dup, pParse->ckOffset-pExpr->iColumn-1, 1);
+}else{
+sqlite3ExprCodeGetColumn(v, pExpr->pTab, pExpr->iColumn, pExpr->iTable);
+}
+break;
+}
+case TK_INTEGER: {
+codeInteger(v, (char*)pExpr->token.z, pExpr->token.n, 0);
+break;
+}
+case TK_FLOAT: {
+codeReal(v, (char*)pExpr->token.z, pExpr->token.n, 0);
+break;
+}
+case TK_STRING: {
+sqlite3DequoteExpr(pParse->db, pExpr);
+sqlite3VdbeOp3(v,OP_String8, 0, 0, (char*)pExpr->token.z, pExpr->token.n);
+break;
+}
+case TK_NULL: {
+sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+break;
+}
+#ifndef SQLITE_OMIT_BLOB_LITERAL
+case TK_BLOB: {
+int n;
+const char *z;
+assert( TK_BLOB==OP_HexBlob );
+n = pExpr->token.n - 3;
+z = (char*)pExpr->token.z + 2;
+assert( n>=0 );
+if( n==0 ){
+z = "";
+}
+sqlite3VdbeOp3(v, op, 0, 0, z, n);
+break;
+}
+#endif
+case TK_VARIABLE: {
+sqlite3VdbeAddOp(v, OP_Variable, pExpr->iTable, 0);
+if( pExpr->token.n>1 ){
+sqlite3VdbeChangeP3(v, -1, (char*)pExpr->token.z, pExpr->token.n);
+}
+break;
+}
+case TK_REGISTER: {
+sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iTable, 0);
+break;
+}
+#ifndef SQLITE_OMIT_CAST
+case TK_CAST: {
+/* Expressions of the form:   CAST(pLeft AS token) */
+int aff, to_op;
+sqlite3ExprCode(pParse, pExpr->pLeft);
+aff = sqlite3AffinityType(&pExpr->token);
+to_op = aff - SQLITE_AFF_TEXT + OP_ToText;
+assert( to_op==OP_ToText    || aff!=SQLITE_AFF_TEXT    );
+assert( to_op==OP_ToBlob    || aff!=SQLITE_AFF_NONE    );
+assert( to_op==OP_ToNumeric || aff!=SQLITE_AFF_NUMERIC );
+assert( to_op==OP_ToInt     || aff!=SQLITE_AFF_INTEGER );
+assert( to_op==OP_ToReal    || aff!=SQLITE_AFF_REAL    );
+sqlite3VdbeAddOp(v, to_op, 0, 0);
+stackChng = 0;
+break;
+}
+#endif /* SQLITE_OMIT_CAST */
+case TK_LT:
+case TK_LE:
+case TK_GT:
+case TK_GE:
+case TK_NE:
+case TK_EQ: {
+assert( TK_LT==OP_Lt );
+assert( TK_LE==OP_Le );
+assert( TK_GT==OP_Gt );
+assert( TK_GE==OP_Ge );
+assert( TK_EQ==OP_Eq );
+assert( TK_NE==OP_Ne );
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3ExprCode(pParse, pExpr->pRight);
+codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, 0, 0);
+stackChng = -1;
+break;
+}
+case TK_AND:
+case TK_OR:
+case TK_PLUS:
+case TK_STAR:
+case TK_MINUS:
+case TK_REM:
+case TK_BITAND:
+case TK_BITOR:
+case TK_SLASH:
+case TK_LSHIFT:
+case TK_RSHIFT:
+case TK_CONCAT: {
+assert( TK_AND==OP_And );
+assert( TK_OR==OP_Or );
+assert( TK_PLUS==OP_Add );
+assert( TK_MINUS==OP_Subtract );
+assert( TK_REM==OP_Remainder );
+assert( TK_BITAND==OP_BitAnd );
+assert( TK_BITOR==OP_BitOr );
+assert( TK_SLASH==OP_Divide );
+assert( TK_LSHIFT==OP_ShiftLeft );
+assert( TK_RSHIFT==OP_ShiftRight );
+assert( TK_CONCAT==OP_Concat );
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3ExprCode(pParse, pExpr->pRight);
+sqlite3VdbeAddOp(v, op, 0, 0);
+stackChng = -1;
+break;
+}
+case TK_UMINUS: {
+Expr *pLeft = pExpr->pLeft;
+assert( pLeft );
+if( pLeft->op==TK_FLOAT || pLeft->op==TK_INTEGER ){
+Token *p = &pLeft->token;
+if( pLeft->op==TK_FLOAT ){
+codeReal(v, (char*)p->z, p->n, 1);
+}else{
+codeInteger(v, (char*)p->z, p->n, 1);
+}
+break;
+}
+/* Fall through into TK_NOT */
+}
+case TK_BITNOT:
+case TK_NOT: {
+assert( TK_BITNOT==OP_BitNot );
+assert( TK_NOT==OP_Not );
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3VdbeAddOp(v, op, 0, 0);
+stackChng = 0;
+break;
+}
+case TK_ISNULL:
+case TK_NOTNULL: {
+int dest;
+assert( TK_ISNULL==OP_IsNull );
+assert( TK_NOTNULL==OP_NotNull );
+sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
+sqlite3ExprCode(pParse, pExpr->pLeft);
+dest = sqlite3VdbeCurrentAddr(v) + 2;
+sqlite3VdbeAddOp(v, op, 1, dest);
+sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);
+stackChng = 0;
+break;
+}
+case TK_AGG_FUNCTION: {
+AggInfo *pInfo = pExpr->pAggInfo;
+if( pInfo==0 ){
+sqlite3ErrorMsg(pParse, "misuse of aggregate: %T",
+&pExpr->span);
+}else{
+sqlite3VdbeAddOp(v, OP_MemLoad, pInfo->aFunc[pExpr->iAgg].iMem, 0);
+}
+break;
+}
+case TK_CONST_FUNC:
+case TK_FUNCTION: {
+ExprList *pList = pExpr->pList;
+int nExpr = pList ? pList->nExpr : 0;
+FuncDef *pDef;
+int nId;
+const char *zId;
+int constMask = 0;
+int i;
+sqlite3 *db = pParse->db;
+u8 enc = ENC(db);
+CollSeq *pColl = 0;
+zId = (char*)pExpr->token.z;
+nId = pExpr->token.n;
+pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
+assert( pDef!=0 );
+nExpr = sqlite3ExprCodeExprList(pParse, pList);
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/* Possibly overload the function if the first argument is
+** a virtual table column.
+**
+** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
+** second argument, not the first, as the argument to test to
+** see if it is a column in a virtual table.  This is done because
+** the left operand of infix functions (the operand we want to
+** control overloading) ends up as the second argument to the
+** function.  The expression "A glob B" is equivalent to
+** "glob(B,A).  We want to use the A in "A glob B" to test
+** for function overloading.  But we use the B term in "glob(B,A)".
+*/
+if( nExpr>=2 && (pExpr->flags & EP_InfixFunc) ){
+pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[1].pExpr);
+}else if( nExpr>0 ){
+pDef = sqlite3VtabOverloadFunction(db, pDef, nExpr, pList->a[0].pExpr);
+}
+#endif
+for(i=0; i<nExpr && i<32; i++){
+if( sqlite3ExprIsConstant(pList->a[i].pExpr) ){
+constMask |= (1<<i);
+}
+if( pDef->needCollSeq && !pColl ){
+pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
+}
+}
+if( pDef->needCollSeq ){
+if( !pColl ) pColl = pParse->db->pDfltColl;
+sqlite3VdbeOp3(v, OP_CollSeq, 0, 0, (char *)pColl, P3_COLLSEQ);
+}
+sqlite3VdbeOp3(v, OP_Function, constMask, nExpr, (char*)pDef, P3_FUNCDEF);
+stackChng = 1-nExpr;
+break;
+}
+#ifndef SQLITE_OMIT_SUBQUERY
+case TK_EXISTS:
+case TK_SELECT: {
+if( pExpr->iColumn==0 ){
+sqlite3CodeSubselect(pParse, pExpr);
+}
+sqlite3VdbeAddOp(v, OP_MemLoad, pExpr->iColumn, 0);
+VdbeComment((v, "# load subquery result"));
+break;
+}
+case TK_IN: {
+int addr;
+char affinity;
+int ckOffset = pParse->ckOffset;
+int eType;
+int iLabel = sqlite3VdbeMakeLabel(v);
+eType = sqlite3FindInIndex(pParse, pExpr, 0);
+/* Figure out the affinity to use to create a key from the results
+** of the expression. affinityStr stores a static string suitable for
+** P3 of OP_MakeRecord.
+*/
+affinity = comparisonAffinity(pExpr);
+sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
+pParse->ckOffset = (ckOffset ? (ckOffset+1) : 0);
+/* Code the <expr> from "<expr> IN (...)". The temporary table
+** pExpr->iTable contains the values that make up the (...) set.
+*/
+sqlite3ExprCode(pParse, pExpr->pLeft);
+addr = sqlite3VdbeCurrentAddr(v);
+sqlite3VdbeAddOp(v, OP_NotNull, -1, addr+4);            /* addr + 0 */
+sqlite3VdbeAddOp(v, OP_Pop, 2, 0);
+sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+sqlite3VdbeAddOp(v, OP_Goto, 0, iLabel);
+if( eType==IN_INDEX_ROWID ){
+int iAddr = sqlite3VdbeCurrentAddr(v)+3;
+sqlite3VdbeAddOp(v, OP_MustBeInt, 1, iAddr);
+sqlite3VdbeAddOp(v, OP_NotExists, pExpr->iTable, iAddr);
+sqlite3VdbeAddOp(v, OP_Goto, pExpr->iTable, iLabel);
+}else{
+sqlite3VdbeOp3(v, OP_MakeRecord, 1, 0, &affinity, 1);   /* addr + 4 */
+sqlite3VdbeAddOp(v, OP_Found, pExpr->iTable, iLabel);
+}
+sqlite3VdbeAddOp(v, OP_AddImm, -1, 0);                  /* addr + 6 */
+sqlite3VdbeResolveLabel(v, iLabel);
+break;
+}
+#endif
+case TK_BETWEEN: {
+Expr *pLeft = pExpr->pLeft;
+	  ExprList::ExprList_item *pLItem = pExpr->pList->a;
+Expr *pRight = pLItem->pExpr;
+sqlite3ExprCode(pParse, pLeft);
+sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
+sqlite3ExprCode(pParse, pRight);
+codeCompare(pParse, pLeft, pRight, OP_Ge, 0, 0);
+sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
+pLItem++;
+pRight = pLItem->pExpr;
+sqlite3ExprCode(pParse, pRight);
+codeCompare(pParse, pLeft, pRight, OP_Le, 0, 0);
+sqlite3VdbeAddOp(v, OP_And, 0, 0);
+break;
+}
+case TK_UPLUS: {
+sqlite3ExprCode(pParse, pExpr->pLeft);
+stackChng = 0;
+break;
+}
+case TK_CASE: {
+int expr_end_label;
+int jumpInst;
+int nExpr;
+int i;
+ExprList *pEList;
+	  ExprList::ExprList_item *aListelem;
+assert(pExpr->pList);
+assert((pExpr->pList->nExpr % 2) == 0);
+assert(pExpr->pList->nExpr > 0);
+pEList = pExpr->pList;
+aListelem = pEList->a;
+nExpr = pEList->nExpr;
+expr_end_label = sqlite3VdbeMakeLabel(v);
+if( pExpr->pLeft ){
+sqlite3ExprCode(pParse, pExpr->pLeft);
+}
+for(i=0; i<nExpr; i=i+2){
+sqlite3ExprCode(pParse, aListelem[i].pExpr);
+if( pExpr->pLeft ){
+sqlite3VdbeAddOp(v, OP_Dup, 1, 1);
+jumpInst = codeCompare(pParse, pExpr->pLeft, aListelem[i].pExpr,
+OP_Ne, 0, 1);
+sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
+}else{
+jumpInst = sqlite3VdbeAddOp(v, OP_IfNot, 1, 0);
+}
+sqlite3ExprCode(pParse, aListelem[i+1].pExpr);
+sqlite3VdbeAddOp(v, OP_Goto, 0, expr_end_label);
+sqlite3VdbeJumpHere(v, jumpInst);
+}
+if( pExpr->pLeft ){
+sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
+}
+if( pExpr->pRight ){
+sqlite3ExprCode(pParse, pExpr->pRight);
+}else{
+sqlite3VdbeAddOp(v, OP_Null, 0, 0);
+}
+sqlite3VdbeResolveLabel(v, expr_end_label);
+break;
+}
+#ifndef SQLITE_OMIT_TRIGGER
+case TK_RAISE: {
+if( !pParse->trigStack ){
+sqlite3ErrorMsg(pParse,
+"RAISE() may only be used within a trigger-program");
+return;
+}
+if( pExpr->iColumn!=OE_Ignore ){
+assert( pExpr->iColumn==OE_Rollback ||
+pExpr->iColumn == OE_Abort ||
+pExpr->iColumn == OE_Fail );
+sqlite3DequoteExpr(pParse->db, pExpr);
+sqlite3VdbeOp3(v, OP_Halt, SQLITE_CONSTRAINT, pExpr->iColumn,
+(char*)pExpr->token.z, pExpr->token.n);
+} else {
+assert( pExpr->iColumn == OE_Ignore );
+sqlite3VdbeAddOp(v, OP_ContextPop, 0, 0);
+sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->trigStack->ignoreJump);
+VdbeComment((v, "# raise(IGNORE)"));
+}
+stackChng = 0;
+break;
+}
+#endif
+}
+if( pParse->ckOffset ){
+pParse->ckOffset += stackChng;
+assert( pParse->ckOffset );
+}
+}
+#ifndef SQLITE_OMIT_TRIGGER
+/*
+** Generate code that evalutes the given expression and leaves the result
+** on the stack.  See also sqlite3ExprCode().
+**
+** This routine might also cache the result and modify the pExpr tree
+** so that it will make use of the cached result on subsequent evaluations
+** rather than evaluate the whole expression again.  Trivial expressions are
+** not cached.  If the expression is cached, its result is stored in a
+** memory location.
+*/
+void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr){
+Vdbe *v = pParse->pVdbe;
+VdbeOp *pOp;
+int iMem;
+int addr1, addr2;
+if( v==0 ) return;
+addr1 = sqlite3VdbeCurrentAddr(v);
+sqlite3ExprCode(pParse, pExpr);
+addr2 = sqlite3VdbeCurrentAddr(v);
+if( addr2>addr1+1
+|| ((pOp = sqlite3VdbeGetOp(v, addr1))!=0 && pOp->opcode==OP_Function) ){
+iMem = pExpr->iTable = pParse->nMem++;
+sqlite3VdbeAddOp(v, OP_MemStore, iMem, 0);
+pExpr->op = TK_REGISTER;
+}
+}
+#endif
+/*
+** Generate code that pushes the value of every element of the given
+** expression list onto the stack.
+**
+** Return the number of elements pushed onto the stack.
+*/
+int sqlite3ExprCodeExprList(
+Parse *pParse,     /* Parsing context */
+ExprList *pList    /* The expression list to be coded */
+){
+	ExprList::ExprList_item *pItem;
+int i, n;
+if( pList==0 ) return 0;
+n = pList->nExpr;
+for(pItem=pList->a, i=n; i>0; i--, pItem++){
+sqlite3ExprCode(pParse, pItem->pExpr);
+}
+return n;
+}
+/*
+** Generate code for a boolean expression such that a jump is made
+** to the label "dest" if the expression is true but execution
+** continues straight thru if the expression is false.
+**
+** If the expression evaluates to NULL (neither true nor false), then
+** take the jump if the jumpIfNull flag is true.
+**
+** This code depends on the fact that certain token values (ex: TK_EQ)
+** are the same as opcode values (ex: OP_Eq) that implement the corresponding
+** operation.  Special comments in vdbe.c and the mkopcodeh.awk script in
+** the make process cause these values to align.  Assert()s in the code
+** below verify that the numbers are aligned correctly.
+*/
+void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
+Vdbe *v = pParse->pVdbe;
+int op = 0;
+int ckOffset = pParse->ckOffset;
+if( v==0 || pExpr==0 ) return;
+op = pExpr->op;
+switch( op ){
+case TK_AND: {
+int d2 = sqlite3VdbeMakeLabel(v);
+sqlite3ExprIfFalse(pParse, pExpr->pLeft, d2, !jumpIfNull);
+sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
+sqlite3VdbeResolveLabel(v, d2);
+break;
+}
+case TK_OR: {
+sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
+sqlite3ExprIfTrue(pParse, pExpr->pRight, dest, jumpIfNull);
+break;
+}
+case TK_NOT: {
+sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
+break;
+}
+case TK_LT:
+case TK_LE:
+case TK_GT:
+case TK_GE:
+case TK_NE:
+case TK_EQ: {
+assert( TK_LT==OP_Lt );
+assert( TK_LE==OP_Le );
+assert( TK_GT==OP_Gt );
+assert( TK_GE==OP_Ge );
+assert( TK_EQ==OP_Eq );
+assert( TK_NE==OP_Ne );
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3ExprCode(pParse, pExpr->pRight);
+codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
+break;
+}
+case TK_ISNULL:
+case TK_NOTNULL: {
+assert( TK_ISNULL==OP_IsNull );
+assert( TK_NOTNULL==OP_NotNull );
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3VdbeAddOp(v, op, 1, dest);
+break;
+}
+case TK_BETWEEN: {
+/* The expression "x BETWEEN y AND z" is implemented as:
+**
+** 1 IF (x < y) GOTO 3
+** 2 IF (x <= z) GOTO <dest>
+** 3 ...
+*/
+int addr;
+Expr *pLeft = pExpr->pLeft;
+Expr *pRight = pExpr->pList->a[0].pExpr;
+sqlite3ExprCode(pParse, pLeft);
+sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
+sqlite3ExprCode(pParse, pRight);
+addr = codeCompare(pParse, pLeft, pRight, OP_Lt, 0, !jumpIfNull);
+pRight = pExpr->pList->a[1].pExpr;
+sqlite3ExprCode(pParse, pRight);
+codeCompare(pParse, pLeft, pRight, OP_Le, dest, jumpIfNull);
+sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
+sqlite3VdbeJumpHere(v, addr);
+sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
+break;
+}
+default: {
+sqlite3ExprCode(pParse, pExpr);
+sqlite3VdbeAddOp(v, OP_If, jumpIfNull, dest);
+break;
+}
+}
+pParse->ckOffset = ckOffset;
+}
+/*
+** Generate code for a boolean expression such that a jump is made
+** to the label "dest" if the expression is false but execution
+** continues straight thru if the expression is true.
+**
+** If the expression evaluates to NULL (neither true nor false) then
+** jump if jumpIfNull is true or fall through if jumpIfNull is false.
+*/
+void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
+Vdbe *v = pParse->pVdbe;
+int op = 0;
+int ckOffset = pParse->ckOffset;
+if( v==0 || pExpr==0 ) return;
+/* The value of pExpr->op and op are related as follows:
+**
+**       pExpr->op            op
+**       ---------          ----------
+**       TK_ISNULL          OP_NotNull
+**       TK_NOTNULL         OP_IsNull
+**       TK_NE              OP_Eq
+**       TK_EQ              OP_Ne
+**       TK_GT              OP_Le
+**       TK_LE              OP_Gt
+**       TK_GE              OP_Lt
+**       TK_LT              OP_Ge
+**
+** For other values of pExpr->op, op is undefined and unused.
+** The value of TK_ and OP_ constants are arranged such that we
+** can compute the mapping above using the following expression.
+** Assert()s verify that the computation is correct.
+*/
+op = ((pExpr->op+(TK_ISNULL&1))^1)-(TK_ISNULL&1);
+/* Verify correct alignment of TK_ and OP_ constants
+*/
+assert( pExpr->op!=TK_ISNULL || op==OP_NotNull );
+assert( pExpr->op!=TK_NOTNULL || op==OP_IsNull );
+assert( pExpr->op!=TK_NE || op==OP_Eq );
+assert( pExpr->op!=TK_EQ || op==OP_Ne );
+assert( pExpr->op!=TK_LT || op==OP_Ge );
+assert( pExpr->op!=TK_LE || op==OP_Gt );
+assert( pExpr->op!=TK_GT || op==OP_Le );
+assert( pExpr->op!=TK_GE || op==OP_Lt );
+switch( pExpr->op ){
+case TK_AND: {
+sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
+sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
+break;
+}
+case TK_OR: {
+int d2 = sqlite3VdbeMakeLabel(v);
+sqlite3ExprIfTrue(pParse, pExpr->pLeft, d2, !jumpIfNull);
+sqlite3ExprIfFalse(pParse, pExpr->pRight, dest, jumpIfNull);
+sqlite3VdbeResolveLabel(v, d2);
+break;
+}
+case TK_NOT: {
+sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
+break;
+}
+case TK_LT:
+case TK_LE:
+case TK_GT:
+case TK_GE:
+case TK_NE:
+case TK_EQ: {
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3ExprCode(pParse, pExpr->pRight);
+codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op, dest, jumpIfNull);
+break;
+}
+case TK_ISNULL:
+case TK_NOTNULL: {
+sqlite3ExprCode(pParse, pExpr->pLeft);
+sqlite3VdbeAddOp(v, op, 1, dest);
+break;
+}
+case TK_BETWEEN: {
+/* The expression is "x BETWEEN y AND z". It is implemented as:
+**
+** 1 IF (x >= y) GOTO 3
+** 2 GOTO <dest>
+** 3 IF (x > z) GOTO <dest>
+*/
+int addr;
+Expr *pLeft = pExpr->pLeft;
+Expr *pRight = pExpr->pList->a[0].pExpr;
+sqlite3ExprCode(pParse, pLeft);
+sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
+sqlite3ExprCode(pParse, pRight);
+addr = sqlite3VdbeCurrentAddr(v);
+codeCompare(pParse, pLeft, pRight, OP_Ge, addr+3, !jumpIfNull);
+sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
+sqlite3VdbeAddOp(v, OP_Goto, 0, dest);
+pRight = pExpr->pList->a[1].pExpr;
+sqlite3ExprCode(pParse, pRight);
+codeCompare(pParse, pLeft, pRight, OP_Gt, dest, jumpIfNull);
+break;
+}
+default: {
+sqlite3ExprCode(pParse, pExpr);
+sqlite3VdbeAddOp(v, OP_IfNot, jumpIfNull, dest);
+break;
+}
+}
+pParse->ckOffset = ckOffset;
+}
+/*
+** Do a deep comparison of two expression trees.  Return TRUE (non-zero)
+** if they are identical and return FALSE if they differ in any way.
+**
+** Sometimes this routine will return FALSE even if the two expressions
+** really are equivalent.  If we cannot prove that the expressions are
+** identical, we return FALSE just to be safe.  So if this routine
+** returns false, then you do not really know for certain if the two
+** expressions are the same.  But if you get a TRUE return, then you
+** can be sure the expressions are the same.  In the places where
+** this routine is used, it does not hurt to get an extra FALSE - that
+** just might result in some slightly slower code.  But returning
+** an incorrect TRUE could lead to a malfunction.
+*/
+int sqlite3ExprCompare(Expr *pA, Expr *pB){
+int i;
+if( pA==0||pB==0 ){
+return pB==pA;
+}
+if( pA->op!=pB->op ) return 0;
+if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 0;
+if( !sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 0;
+if( !sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 0;
+if( pA->pList ){
+if( pB->pList==0 ) return 0;
+if( pA->pList->nExpr!=pB->pList->nExpr ) return 0;
+for(i=0; i<pA->pList->nExpr; i++){
+if( !sqlite3ExprCompare(pA->pList->a[i].pExpr, pB->pList->a[i].pExpr) ){
+return 0;
+}
+}
+}else if( pB->pList ){
+return 0;
+}
+if( pA->pSelect || pB->pSelect ) return 0;
+if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 0;
+if( pA->op!=TK_COLUMN && pA->token.z ){
+if( pB->token.z==0 ) return 0;
+if( pB->token.n!=pA->token.n ) return 0;
+if( sqlite3StrNICmp((char*)pA->token.z,(char*)pB->token.z,pB->token.n)!=0 ){
+return 0;
+}
+}
+return 1;
+}
+/*
+** Add a new element to the pAggInfo->aCol[] array.  Return the index of
+** the new element.  Return a negative number if malloc fails.
+*/
+static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
+int i;
+pInfo->aCol = (AggInfo::AggInfo_col*)sqlite3ArrayAllocate(
+db,
+pInfo->aCol,
+sizeof(pInfo->aCol[0]),
+3,
+&pInfo->nColumn,
+&pInfo->nColumnAlloc,
+&i
+);
+return i;
+}
+/*
+** Add a new element to the pAggInfo->aFunc[] array.  Return the index of
+** the new element.  Return a negative number if malloc fails.
+*/
+static int addAggInfoFunc(sqlite3 *db, AggInfo *pInfo){
+int i;
+pInfo->aFunc = (AggInfo::AggInfo_func*)sqlite3ArrayAllocate(
+db,
+pInfo->aFunc,
+sizeof(pInfo->aFunc[0]),
+3,
+&pInfo->nFunc,
+&pInfo->nFuncAlloc,
+&i
+);
+return i;
+}
+/*
+** This is an xFunc for walkExprTree() used to implement
+** sqlite3ExprAnalyzeAggregates().  See sqlite3ExprAnalyzeAggregates
+** for additional information.
+**
+** This routine analyzes the aggregate function at pExpr.
+*/
+static int analyzeAggregate(void *pArg, Expr *pExpr){
+int i;
+NameContext *pNC = (NameContext *)pArg;
+Parse *pParse = pNC->pParse;
+SrcList *pSrcList = pNC->pSrcList;
+AggInfo *pAggInfo = pNC->pAggInfo;
+switch( pExpr->op ){
+case TK_AGG_COLUMN:
+case TK_COLUMN: {
+/* Check to see if the column is in one of the tables in the FROM
+** clause of the aggregate query */
+if( pSrcList ){
+		  SrcList::SrcList_item *pItem = pSrcList->a;
+for(i=0; i<pSrcList->nSrc; i++, pItem++){
+			AggInfo::AggInfo_col *pCol;
+if( pExpr->iTable==pItem->iCursor ){
+/* If we reach this point, it means that pExpr refers to a table
+** that is in the FROM clause of the aggregate query.
+**
+** Make an entry for the column in pAggInfo->aCol[] if there
+** is not an entry there already.
+*/
+			  int k=0;
+pCol = pAggInfo->aCol;
+for(k=0; k<pAggInfo->nColumn; k++, pCol++){
+if( pCol->iTable==pExpr->iTable &&
+pCol->iColumn==pExpr->iColumn ){
+break;
+}
+}
+if( (k>=pAggInfo->nColumn)
+&& (k = addAggInfoColumn(pParse->db, pAggInfo))>=0
+){
+pCol = &pAggInfo->aCol[k];
+pCol->pTab = pExpr->pTab;
+pCol->iTable = pExpr->iTable;
+pCol->iColumn = pExpr->iColumn;
+pCol->iMem = pParse->nMem++;
+pCol->iSorterColumn = -1;
+pCol->pExpr = pExpr;
+if( pAggInfo->pGroupBy ){
+int j, n;
+ExprList *pGB = pAggInfo->pGroupBy;
+				ExprList::ExprList_item *pTerm = pGB->a;
+n = pGB->nExpr;
+for(j=0; j<n; j++, pTerm++){
+Expr *pE = pTerm->pExpr;
+if( pE->op==TK_COLUMN && pE->iTable==pExpr->iTable &&
+pE->iColumn==pExpr->iColumn ){
+pCol->iSorterColumn = j;
+break;
+}
+}
+}
+if( pCol->iSorterColumn<0 ){
+pCol->iSorterColumn = pAggInfo->nSortingColumn++;
+}
+}
+/* There is now an entry for pExpr in pAggInfo->aCol[] (either
+** because it was there before or because we just created it).
+** Convert the pExpr to be a TK_AGG_COLUMN referring to that
+** pAggInfo->aCol[] entry.
+*/
+pExpr->pAggInfo = pAggInfo;
+pExpr->op = TK_AGG_COLUMN;
+pExpr->iAgg = k;
+break;
+} /* endif pExpr->iTable==pItem->iCursor */
+} /* end loop over pSrcList */
+}
+return 1;
+}
+case TK_AGG_FUNCTION: {
+/* The pNC->nDepth==0 test causes aggregate functions in subqueries
+** to be ignored */
+if( pNC->nDepth==0 ){
+/* Check to see if pExpr is a duplicate of another aggregate
+** function that is already in the pAggInfo structure
+*/
+		  AggInfo::AggInfo_func *pItem = pAggInfo->aFunc;
+for(i=0; i<pAggInfo->nFunc; i++, pItem++){
+if( sqlite3ExprCompare(pItem->pExpr, pExpr) ){
+break;
+}
+}
+if( i>=pAggInfo->nFunc ){
+/* pExpr is original.  Make a new entry in pAggInfo->aFunc[]
+*/
+u8 enc = ENC(pParse->db);
+i = addAggInfoFunc(pParse->db, pAggInfo);
+if( i>=0 ){
+pItem = &pAggInfo->aFunc[i];
+pItem->pExpr = pExpr;
+pItem->iMem = pParse->nMem++;
+pItem->pFunc = sqlite3FindFunction(pParse->db,
+(char*)pExpr->token.z, pExpr->token.n,
+pExpr->pList ? pExpr->pList->nExpr : 0, enc, 0);
+if( pExpr->flags & EP_Distinct ){
+pItem->iDistinct = pParse->nTab++;
+}else{
+pItem->iDistinct = -1;
+}
+}
+}
+/* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
+*/
+pExpr->iAgg = i;
+pExpr->pAggInfo = pAggInfo;
+return 1;
+}
+}
+}
+/* Recursively walk subqueries looking for TK_COLUMN nodes that need
+** to be changed to TK_AGG_COLUMN.  But increment nDepth so that
+** TK_AGG_FUNCTION nodes in subqueries will be unchanged.
+*/
+if( pExpr->pSelect ){
+pNC->nDepth++;
+walkSelectExpr(pExpr->pSelect, analyzeAggregate, pNC);
+pNC->nDepth--;
+}
+return 0;
+}
+/*
+** Analyze the given expression looking for aggregate functions and
+** for variables that need to be added to the pParse->aAgg[] array.
+** Make additional entries to the pParse->aAgg[] array as necessary.
+**
+** This routine should only be called after the expression has been
+** analyzed by sqlite3ExprResolveNames().
+**
+** If errors are seen, leave an error message in zErrMsg and return
+** the number of errors.
+*/
+int sqlite3ExprAnalyzeAggregates(NameContext *pNC, Expr *pExpr){
+int nErr = pNC->pParse->nErr;
+walkExprTree(pExpr, analyzeAggregate, pNC);
+return pNC->pParse->nErr - nErr;
+}
+/*
+** Call sqlite3ExprAnalyzeAggregates() for every expression in an
+** expression list.  Return the number of errors.
+**
+** If an error is found, the analysis is cut short.
+*/
+int sqlite3ExprAnalyzeAggList(NameContext *pNC, ExprList *pList){
+	ExprList::ExprList_item *pItem;
+int i;
+int nErr = 0;
+if( pList ){
+for(pItem=pList->a, i=0; nErr==0 && i<pList->nExpr; i++, pItem++){
+nErr += sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
+}
+}
+return nErr;
+}