From cf374febf5a06dfbf02f5d6d74f5d156cb9af62a Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Thu, 16 Dec 1999 20:07:41 +0000
Subject: [PATCH] >Turning nextval and currval into keywords is not an
acceptable way to >go about this. That will risk breaking existing
applications that use >those names as column names. > >It should actually
almost work to write sq.nextval as things stand, >because Postgres has for a
long time considered table.function and >function(table) to be
interchangeable notations for certain kinds of >functions. nextval doesn't
seem to be one of that kind of function, >at the moment. I'd suggest leaving
the grammar as it was, and taking a >look at ParseFuncOrColumn in
parse_func.c to see if you can't persuade >it to accept the sequence
functions in that style.
OK, good point. I tried to implement it somewhere else and ended up
extending transformAttr. Attached you'll find the patch.
Jeroen van Vianen
---
src/backend/parser/parse_expr.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index ee43be41950..5b50de1494b 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 1.60 1999/12/10 07:37:35 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.61 1999/12/16 20:07:41 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -531,6 +531,30 @@ static Node *
transformAttr(ParseState *pstate, Attr *att, int precedence)
{
Node *basenode;
+ char * attribute;
+
+ /* Get the name of the first attribute */
+ if ((att != NULL) && (lfirst(att->attrs) != NULL))
+ {
+ /*
+ * Special case for name.nextval and name.currval, assume it's a
+ * sequence and transform to function call to nextval('name') and
+ * currval('name')
+ */
+ attribute = pstrdup(((Value *) lfirst(att->attrs))->val.str);
+ if ((strcasecmp(attribute, "nextval") == 0) ||
+ (strcasecmp(attribute, "currval") == 0))
+ {
+ Value *s = makeNode(Value);
+
+ s->type = T_String;
+ s->val.str = att->relname;
+
+ return ParseFuncOrColumn(pstate, attribute,
+ lcons(make_const(s), NIL), false, false,
+ &pstate->p_last_resno, precedence);
+ }
+ }
basenode = ParseNestedFuncOrColumn(pstate, att, &pstate->p_last_resno,
precedence);
--
GitLab