I wrote: > I'm talking about the underlined SELECT, not the one inside the > aggregate. AFAICS this one is totally useless.
Oh, wait. It is useless in the query as written, but now that I think twice about what you're trying to accomplish, you do need three levels of SELECT keywords. Just not like that. I think what you actually want is SELECT ... (SELECT GROUP_CONCAT(t.fname, '; ') FROM (SELECT s2.fname FROM student AS s2 WHERE s2.id=s.id ORDER BY fname) AS t) AS students, ... FROM student AS s What you wrote instead is just wrong --- it would fail if there were multiple students with the same id (can that actually happen? Maybe there's more wrong with this query...), because what you wrote is a scalar sub-SELECT inside an aggregate call that belongs to the outermost query. regards, tom lane -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs