Index: src/expr.c ================================================================== --- src/expr.c +++ src/expr.c @@ -89,11 +89,11 @@ s.n = sqlite3Strlen30(s.z); return sqlite3ExprAddCollateToken(pParse, pExpr, &s, 0); } /* -** Skip over any TK_COLLATE or TK_AS operators and any unlikely() +** Skip over any TK_COLLATE operators and any unlikely() ** or likelihood() function at the root of an expression. */ Expr *sqlite3ExprSkipCollate(Expr *pExpr){ while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){ if( ExprHasProperty(pExpr, EP_Unlikely) ){ @@ -100,11 +100,11 @@ assert( !ExprHasProperty(pExpr, EP_xIsSelect) ); assert( pExpr->x.pList->nExpr>0 ); assert( pExpr->op==TK_FUNCTION ); pExpr = pExpr->x.pList->a[0].pExpr; }else{ - assert( pExpr->op==TK_COLLATE || pExpr->op==TK_AS ); + assert( pExpr->op==TK_COLLATE ); pExpr = pExpr->pLeft; } } return pExpr; } @@ -2699,14 +2699,10 @@ } case TK_REGISTER: { inReg = pExpr->iTable; break; } - case TK_AS: { - inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); - break; - } #ifndef SQLITE_OMIT_CAST case TK_CAST: { /* Expressions of the form: CAST(pLeft AS token) */ inReg = sqlite3ExprCodeTarget(pParse, pExpr->pLeft, target); if( inReg!=target ){ Index: src/resolve.c ================================================================== --- src/resolve.c +++ src/resolve.c @@ -43,34 +43,10 @@ /* ** Turn the pExpr expression into an alias for the iCol-th column of the ** result set in pEList. ** -** If the result set column is a simple column reference, then this routine -** makes an exact copy. But for any other kind of expression, this -** routine make a copy of the result set column as the argument to the -** TK_AS operator. The TK_AS operator causes the expression to be -** evaluated just once and then reused for each alias. -** -** The reason for suppressing the TK_AS term when the expression is a simple -** column reference is so that the column reference will be recognized as -** usable by indices within the WHERE clause processing logic. -** -** The TK_AS operator is inhibited if zType[0]=='G'. This means -** that in a GROUP BY clause, the expression is evaluated twice. Hence: -** -** SELECT random()%5 AS x, count(*) FROM tab GROUP BY x -** -** Is equivalent to: -** -** SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5 -** -** The result of random()%5 in the GROUP BY clause is probably different -** from the result in the result-set. On the other hand Standard SQL does -** not allow the GROUP BY clause to contain references to result-set columns. -** So this should never come up in well-formed queries. -** ** If the reference is followed by a COLLATE operator, then make sure ** the COLLATE operator is preserved. For example: ** ** SELECT a+b, c+d FROM t1 ORDER BY 1 COLLATE nocase; ** @@ -100,23 +76,15 @@ pOrig = pEList->a[iCol].pExpr; assert( pOrig!=0 ); db = pParse->db; pDup = sqlite3ExprDup(db, pOrig, 0); if( pDup==0 ) return; - if( pOrig->op!=TK_COLUMN && zType[0]!='G' ){ - incrAggFunctionDepth(pDup, nSubquery); - pDup = sqlite3PExpr(pParse, TK_AS, pDup, 0, 0); - if( pDup==0 ) return; - ExprSetProperty(pDup, EP_Skip); - if( pEList->a[iCol].u.x.iAlias==0 ){ - pEList->a[iCol].u.x.iAlias = (u16)(++pParse->nAlias); - } - pDup->iTable = pEList->a[iCol].u.x.iAlias; - } + if( zType[0]!='G' ) incrAggFunctionDepth(pDup, nSubquery); if( pExpr->op==TK_COLLATE ){ pDup = sqlite3ExprAddCollateString(pParse, pDup, pExpr->u.zToken); } + ExprSetProperty(pDup, EP_Alias); /* Before calling sqlite3ExprDelete(), set the EP_Static flag. This ** prevents ExprDelete() from deleting the Expr structure itself, ** allowing it to be repopulated by the memcpy() on the following line. ** The pExpr->u.zToken might point into memory that will be freed by the @@ -504,11 +472,11 @@ pExpr->pRight = 0; pExpr->op = (isTrigger ? TK_TRIGGER : TK_COLUMN); lookupname_end: if( cnt==1 ){ assert( pNC!=0 ); - if( pExpr->op!=TK_AS ){ + if( !ExprHasProperty(pExpr, EP_Alias) ){ sqlite3AuthRead(pParse, pExpr, pSchema, pNC->pSrcList); } /* Increment the nRef value on all name contexts from TopNC up to ** the point where the name matched. */ for(;;){ Index: src/sqliteInt.h ================================================================== --- src/sqliteInt.h +++ src/sqliteInt.h @@ -2133,10 +2133,11 @@ #define EP_NoReduce 0x020000 /* Cannot EXPRDUP_REDUCE this Expr */ #define EP_Unlikely 0x040000 /* unlikely() or likelihood() function */ #define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */ #define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */ #define EP_Subquery 0x200000 /* Tree contains a TK_SELECT operator */ +#define EP_Alias 0x400000 /* Is an alias for a result set column */ /* ** Combinations of two or more EP_* flags */ #define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */ Index: src/treeview.c ================================================================== --- src/treeview.c +++ src/treeview.c @@ -251,15 +251,10 @@ } case TK_REGISTER: { sqlite3TreeViewLine(pView,"REGISTER(%d)", pExpr->iTable); break; } - case TK_AS: { - sqlite3TreeViewLine(pView,"AS %Q", pExpr->u.zToken); - sqlite3TreeViewExpr(pView, pExpr->pLeft, 0); - break; - } case TK_ID: { sqlite3TreeViewLine(pView,"ID \"%w\"", pExpr->u.zToken); break; } #ifndef SQLITE_OMIT_CAST Index: test/indexexpr1.test ================================================================== --- test/indexexpr1.test +++ test/indexexpr1.test @@ -195,7 +195,28 @@ SELECT a FROM t3 WHERE CAST(a AS text)<='10' ORDER BY +a; } {1 10} do_catchsql_test indexexpr1-410 { INSERT INTO t3 SELECT * FROM t3 WHERE rowid=10; } {1 {UNIQUE constraint failed: index 't3abc'}} + +do_execsql_test indexexpr1-500 { + CREATE TABLE t5(a); + CREATE TABLE cnt(x); + WITH RECURSIVE + c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<5) + INSERT INTO cnt(x) SELECT x FROM c; + INSERT INTO t5(a) SELECT printf('abc%03dxyz',x) FROM cnt; + CREATE INDEX t5ax ON t5( substr(a,4,3) ); +} {} +do_execsql_test indexexpr1-510 { + -- The use of the "k" alias in the WHERE clause is technically + -- illegal, but SQLite allows it for historical reasons. In this + -- test and the next, verify that "k" can be used by the t5ax index + SELECT substr(a,4,3) AS k FROM cnt, t5 WHERE k=printf('%03d',x); +} {001 002 003 004 005} +do_execsql_test indexexpr1-510eqp { + EXPLAIN QUERY PLAN + SELECT substr(a,4,3) AS k FROM cnt, t5 WHERE k=printf('%03d',x); +} {/USING INDEX t5ax/} + finish_test