T E Schmitz <[EMAIL PROTECTED]> writes:
> There's a German saying "Go and find a parking-meter", i.e. suggesting to pop a
> coin in the parking-meter and talk to it as nobody else wants to listen. ;-)
Yes well I anticipated such a response. So I tried my hand at it myself.
Well I finally found a problem tractable enough for me to get all the way from
start to end in a single sitting. Here's a simple solution to my complaint.
This patch allows subqueries without aliases. This is SQL-non-spec-compliant
syntax that Oracle supports and many users expect to work. It's also just
damned convenient, especially for simple ad-hoc queries.
There was a comment saying an alias name would have to be constructed so I
took that approach. It seems like it would have been cleaner to just ensure
that the code doesn't fail when no alias is present. But I have no idea how
much work would be involved in that, so I just took advice from the anonymous
author of the comment.
Incidentally, It seems weird to me that the counter doesn't reset for every
query. Perhaps I should change that?
Index: src/backend/parser/gram.y
===
RCS file: /projects/cvsroot/pgsql-server/src/backend/parser/gram.y,v
retrieving revision 2.475
diff -u -p -c -r2.475 gram.y
cvs diff: conflicting specifications of output style
*** src/backend/parser/gram.y 29 Aug 2004 04:12:35 - 2.475
--- src/backend/parser/gram.y 20 Sep 2004 21:34:13 -
*** table_ref: relation_expr
*** 5158,5177
{
/*
* The SQL spec does not permit a subselect
!* () without an alias clause,
!* so we don't either. This avoids the problem
!* of needing to invent a unique refname for
it.
!* That could be surmounted if there's
sufficient
!* popular demand, but for now let's just
implement
!* the spec and see if anyone complains.
!* However, it does seem like a good idea to
emit
!* an error message that's better than "syntax
error".
*/
! ereport(ERROR,
! (errcode(ERRCODE_SYNTAX_ERROR),
!errmsg("subquery in FROM must
have an alias"),
!errhint("For example, FROM
(SELECT ...) [AS] foo.")));
! $$ = NULL;
}
| select_with_parens alias_clause
{
--- 5158,5172
{
/*
* The SQL spec does not permit a subselect
!* () without an alias clause,
We surmount
!* this because of popular demand by gining up
a fake name
!* in transformRangeSubselect
*/
!
! RangeSubselect *n = makeNode(RangeSubselect);
! n->subquery = $1;
! n->alias = NULL;
! $$ = (Node *) n;
}
| select_with_parens alias_clause
{
Index: src/backend/parser/parse_clause.c
===
RCS file: /projects/cvsroot/pgsql-server/src/backend/parser/parse_clause.c,v
retrieving revision 1.136
diff -u -p -c -r1.136 parse_clause.c
cvs diff: conflicting specifications of output style
*** src/backend/parser/parse_clause.c 29 Aug 2004 05:06:44 - 1.136
--- src/backend/parser/parse_clause.c 20 Sep 2004 21:34:14 -
*** transformRangeSubselect(ParseState *psta
*** 418,426
* an unlabeled subselect.
*/
if (r->alias == NULL)
! ereport(ERROR,
! (errcode(ERRCODE_SYNTAX_ERROR),
!errmsg("subquery in FROM must have an alias")));
/*
* Analyze and transform the subquery.
--- 418,434
* an unlabeled subselect.
*/
if (r->alias == NULL)
! {
! static int subquery_counter = 1;
! static char buf[30];
!
! sprintf(buf, "*SUBQUERY*%d*", subquery_counter++);
!
! r->alias = make