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-rw-r--r--src/backend/parser/gram.y44
-rw-r--r--src/backend/parser/parse_expr.c48
2 files changed, 65 insertions, 27 deletions
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 1809d515461..7626fe0e449 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.391 2003/01/08 00:22:27 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.392 2003/01/09 20:50:51 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -5420,28 +5420,30 @@ opt_interval:
/* Expressions using row descriptors
* Define row_descriptor to allow yacc to break the reduce/reduce conflict
- * with singleton expressions. Use SQL99's ROW keyword to allow rows of
- * one element.
+ * with singleton expressions. Use SQL99's ROW keyword to allow rows of
+ * one element.
*/
r_expr: row IN_P select_with_parens
{
SubLink *n = makeNode(SubLink);
n->lefthand = $1;
n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
- n->useor = FALSE;
n->subLinkType = ANY_SUBLINK;
+ /* operIsEquals and useOr will be set later */
n->subselect = $3;
$$ = (Node *)n;
}
| row NOT IN_P select_with_parens
{
+ /* Make an IN node */
SubLink *n = makeNode(SubLink);
n->lefthand = $1;
- n->oper = (List *) makeSimpleA_Expr(OP, "<>", NULL, NULL);
- n->useor = TRUE;
- n->subLinkType = ALL_SUBLINK;
+ n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
+ n->subLinkType = ANY_SUBLINK;
+ /* operIsEquals and useOr will be set later */
n->subselect = $4;
- $$ = (Node *)n;
+ /* Stick a NOT on top */
+ $$ = (Node *) makeA_Expr(NOT, NIL, NULL, (Node *) n);
}
| row qual_all_Op sub_type select_with_parens
%prec Op
@@ -5449,11 +5451,8 @@ r_expr: row IN_P select_with_parens
SubLink *n = makeNode(SubLink);
n->lefthand = $1;
n->oper = (List *) makeA_Expr(OP, $2, NULL, NULL);
- if (strcmp(strVal(llast($2)), "<>") == 0)
- n->useor = TRUE;
- else
- n->useor = FALSE;
n->subLinkType = $3;
+ /* operIsEquals and useOr will be set later */
n->subselect = $4;
$$ = (Node *)n;
}
@@ -5463,11 +5462,8 @@ r_expr: row IN_P select_with_parens
SubLink *n = makeNode(SubLink);
n->lefthand = $1;
n->oper = (List *) makeA_Expr(OP, $2, NULL, NULL);
- if (strcmp(strVal(llast($2)), "<>") == 0)
- n->useor = TRUE;
- else
- n->useor = FALSE;
n->subLinkType = MULTIEXPR_SUBLINK;
+ /* operIsEquals and useOr will be set later */
n->subselect = $3;
$$ = (Node *)n;
}
@@ -5850,8 +5846,8 @@ a_expr: c_expr { $$ = $1; }
SubLink *n = (SubLink *)$3;
n->lefthand = makeList1($1);
n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
- n->useor = FALSE;
n->subLinkType = ANY_SUBLINK;
+ /* operIsEquals and useOr will be set later */
$$ = (Node *)n;
}
else
@@ -5875,12 +5871,14 @@ a_expr: c_expr { $$ = $1; }
/* in_expr returns a SubLink or a list of a_exprs */
if (IsA($4, SubLink))
{
+ /* Make an IN node */
SubLink *n = (SubLink *)$4;
n->lefthand = makeList1($1);
- n->oper = (List *) makeSimpleA_Expr(OP, "<>", NULL, NULL);
- n->useor = FALSE;
- n->subLinkType = ALL_SUBLINK;
- $$ = (Node *)n;
+ n->oper = (List *) makeSimpleA_Expr(OP, "=", NULL, NULL);
+ n->subLinkType = ANY_SUBLINK;
+ /* operIsEquals and useOr will be set later */
+ /* Stick a NOT on top */
+ $$ = (Node *) makeA_Expr(NOT, NIL, NULL, (Node *) n);
}
else
{
@@ -5903,8 +5901,8 @@ a_expr: c_expr { $$ = $1; }
SubLink *n = makeNode(SubLink);
n->lefthand = makeList1($1);
n->oper = (List *) makeA_Expr(OP, $2, NULL, NULL);
- n->useor = FALSE; /* doesn't matter since only one col */
n->subLinkType = $3;
+ /* operIsEquals and useOr will be set later */
n->subselect = $4;
$$ = (Node *)n;
}
@@ -6447,7 +6445,6 @@ c_expr: columnref { $$ = (Node *) $1; }
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->oper = NIL;
- n->useor = FALSE;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $1;
$$ = (Node *)n;
@@ -6457,7 +6454,6 @@ c_expr: columnref { $$ = (Node *) $1; }
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->oper = NIL;
- n->useor = FALSE;
n->subLinkType = EXISTS_SUBLINK;
n->subselect = $2;
$$ = (Node *)n;
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 9705ca5d7de..3701f41dca0 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.138 2002/12/27 20:06:19 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.139 2003/01/09 20:50:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -367,6 +367,8 @@ transformExpr(ParseState *pstate, Node *expr)
*/
sublink->lefthand = NIL;
sublink->oper = NIL;
+ sublink->operIsEquals = FALSE;
+ sublink->useOr = FALSE;
}
else if (sublink->subLinkType == EXPR_SUBLINK)
{
@@ -391,27 +393,60 @@ transformExpr(ParseState *pstate, Node *expr)
*/
sublink->lefthand = NIL;
sublink->oper = NIL;
+ sublink->operIsEquals = FALSE;
+ sublink->useOr = FALSE;
}
else
{
/* ALL, ANY, or MULTIEXPR: generate operator list */
List *left_list = sublink->lefthand;
List *right_list = qtree->targetList;
+ int row_length = length(left_list);
+ bool needNot = false;
List *op;
char *opname;
List *elist;
+ /* transform lefthand expressions */
foreach(elist, left_list)
lfirst(elist) = transformExpr(pstate, lfirst(elist));
+ /* get the combining-operator name */
Assert(IsA(sublink->oper, A_Expr));
op = ((A_Expr *) sublink->oper)->name;
opname = strVal(llast(op));
sublink->oper = NIL;
+ /*
+ * If the expression is "<> ALL" (with unqualified opname)
+ * then convert it to "NOT IN". This is a hack to improve
+ * efficiency of expressions output by pre-7.4 Postgres.
+ */
+ if (sublink->subLinkType == ALL_SUBLINK &&
+ length(op) == 1 && strcmp(opname, "<>") == 0)
+ {
+ sublink->subLinkType = ANY_SUBLINK;
+ opname = pstrdup("=");
+ op = makeList1(makeString(opname));
+ needNot = true;
+ }
+
+ /* Set operIsEquals if op is unqualified "=" */
+ if (length(op) == 1 && strcmp(opname, "=") == 0)
+ sublink->operIsEquals = TRUE;
+ else
+ sublink->operIsEquals = FALSE;
+
+ /* Set useOr if op is "<>" (possibly qualified) */
+ if (strcmp(opname, "<>") == 0)
+ sublink->useOr = TRUE;
+ else
+ sublink->useOr = FALSE;
+
/* Combining operators other than =/<> is dubious... */
- if (length(left_list) != 1 &&
- strcmp(opname, "=") != 0 && strcmp(opname, "<>") != 0)
+ if (row_length != 1 &&
+ strcmp(opname, "=") != 0 &&
+ strcmp(opname, "<>") != 0)
elog(ERROR, "Row comparison cannot use operator %s",
opname);
@@ -474,6 +509,13 @@ transformExpr(ParseState *pstate, Node *expr)
}
if (left_list != NIL)
elog(ERROR, "Subselect has too few fields");
+
+ if (needNot)
+ {
+ expr = coerce_to_boolean(expr, "NOT");
+ expr = (Node *) makeBoolExpr(NOT_EXPR,
+ makeList1(expr));
+ }
}
result = (Node *) expr;
break;
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-01 10:09:04 +0000