"Itzinger, Oskar" <oitzinger@opec.org> writes:
> /why/ does SELECT give up with
> ERROR: SQL-language function not supported in this context.
The message seems perfectly clear to me ;-)
> - How can I rectify this situation
Update to 7.1:
regression=# SELECT id, foo_a(entry) FROM tmp GROUP BY id;
id | foo_a
-----+------------
abc | , kls, mnr
def | , opq, zyw
(2 rows)
Not that I'd recommend a SQL function for an aggregate, mind you.
plpgsql would probably be faster/better.
regards, tom lane