From eeb3abe0176999b1cf6a7a091bcc73fc76f6111c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 11 Jul 1999 02:04:19 +0000
Subject: [PATCH] Ignore resjunk targetlist entries when matching arguments to
a SubLink with the subplan's targetlist. This fixes a problem seen with, for
example, a subselect that uses GROUP BY.
---
src/backend/parser/parse_expr.c | 55 ++++++++++++++++++++-------------
1 file changed, 33 insertions(+), 22 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 48c6f9f960e..4aecd1f0481 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.49 1999/05/26 12:55:37 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.50 1999/07/11 02:04:19 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -278,7 +278,6 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
SubLink *sublink = (SubLink *) expr;
List *qtrees;
Query *qtree;
- List *llist;
pstate->p_hasSubLinks = true;
qtrees = parse_analyze(lcons(sublink->subselect, NIL), pstate);
@@ -293,36 +292,48 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
if (sublink->subLinkType != EXISTS_SUBLINK)
{
char *op = lfirst(sublink->oper);
- List *left_expr = sublink->lefthand;
- List *right_expr = ((Query *) sublink->subselect)->targetList;
+ List *left_list = sublink->lefthand;
+ List *right_list = qtree->targetList;
List *elist;
- foreach(llist, left_expr)
- lfirst(llist) = transformExpr(pstate, lfirst(llist), precedence);
+ foreach(elist, left_list)
+ lfirst(elist) = transformExpr(pstate, lfirst(elist),
+ precedence);
- if (length(left_expr) != length(right_expr))
- elog(ERROR, "parser: Subselect has too many or too few fields.");
-
- if (length(left_expr) > 1 &&
+ if (length(left_list) > 1 &&
strcmp(op, "=") != 0 && strcmp(op, "<>") != 0)
- elog(ERROR, "parser: '%s' is not relational operator", op);
+ elog(ERROR, "parser: '%s' is not relational operator",
+ op);
sublink->oper = NIL;
- foreach(elist, left_expr)
+
+ /* Scan subquery's targetlist to find values that will be
+ * matched against lefthand values. We need to ignore
+ * resjunk targets, so doing the outer iteration over
+ * right_list is easier than doing it over left_list.
+ */
+ while (right_list != NIL)
{
- Node *lexpr = lfirst(elist);
- Node *rexpr = lfirst(right_expr);
- TargetEntry *tent = (TargetEntry *) rexpr;
+ TargetEntry *tent = (TargetEntry *) lfirst(right_list);
+ Node *lexpr;
Expr *op_expr;
- op_expr = make_op(op, lexpr, tent->expr);
-
- if (op_expr->typeOid != BOOLOID &&
- sublink->subLinkType != EXPR_SUBLINK)
- elog(ERROR, "parser: '%s' must return 'bool' to be used with quantified predicate subquery", op);
- sublink->oper = lappend(sublink->oper, op_expr);
- right_expr = lnext(right_expr);
+ if (! tent->resdom->resjunk)
+ {
+ if (left_list == NIL)
+ elog(ERROR, "parser: Subselect has too many fields.");
+ lexpr = lfirst(left_list);
+ left_list = lnext(left_list);
+ op_expr = make_op(op, lexpr, tent->expr);
+ if (op_expr->typeOid != BOOLOID &&
+ sublink->subLinkType != EXPR_SUBLINK)
+ elog(ERROR, "parser: '%s' must return 'bool' to be used with quantified predicate subquery", op);
+ sublink->oper = lappend(sublink->oper, op_expr);
+ }
+ right_list = lnext(right_list);
}
+ if (left_list != NIL)
+ elog(ERROR, "parser: Subselect has too few fields.");
}
else
sublink->oper = NIL;
--
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