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 -0000 2.475 --- src/backend/parser/gram.y 20 Sep 2004 21:34:13 -0000 *************** table_ref: relation_expr *** 5158,5177 **** { /* * The SQL spec does not permit a subselect ! * (<derived_table>) 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."))); ! $$ = NULL; } | select_with_parens alias_clause { --- 5158,5172 ---- { /* * The SQL spec does not permit a subselect ! * (<derived_table>) without an alias clause, We surmount ! * this because of popular demand by gining up a fake name ! * in transformRangeSubselect */ ! ! RangeSubselect *n = makeNode(RangeSubselect); ! n->subquery = $1; ! n->alias = NULL; ! $$ = (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 -0000 1.136 --- src/backend/parser/parse_clause.c 20 Sep 2004 21:34:14 -0000 *************** 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 = makeNode(Alias); ! r->alias->aliasname = pstrdup(buf); ! r->alias->colnames = NULL; ! } ! /* * Analyze and transform the subquery. ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings