What about replacing the table by SELECT * FROM my_table ORDER BY num
i.e. something like SELECT cat, LAST(id), LAST(num) FROM (SELECT * FROM my_table ORDER BY num) AS foo GROUP_BY cat; Hope it works, just guessing it might help :-) regards Tomas > SELECT cat, MAX(num) FROM my_table GROUP_BY cat; > > But if I add the "id" column, of course it doesn't work, since it's not > in an aggregate function or in the GROUP_BY clause. So I found a post > at http://archives.postgresql.org/pgsql-hackers/2006-03/msg01324.php > which describes how to add a "FIRST" and "LAST" aggregate function to > PGSQL. However, first and last don't seem to help unless you are able > to "subsort" the grouping by the # (ie, group by cat, then subsort on > num, and select the "last" one of the group). > > I would think something like the following would work, except that PGSQL > does not like the SQL generated (it basically says I can't have a > GROUP_BY after an ORDER_BY). And if I move the "ORDER_BY" to the end, > that just orders the returned groupings, so that doesn't help me either. > > SELECT cat, LAST(id), LAST(num) FROM my_table ORDER_BY num GROUP_BY cat; > > > So does anyone know how to sort *within* a grouping so that FIRST and > LAST return meaningful results? -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
