2010/8/4 Thom Brown <t...@linux.com>: > On 4 August 2010 14:04, Robert Haas <robertmh...@gmail.com> wrote: >> On Wed, Aug 4, 2010 at 6:03 AM, Thom Brown <t...@linux.com> wrote: >>> Actually, this rings a bell. I think this may have been raised >>> before, something to do with the delimiter being accepted as one of >>> the order by values. If this isn't really a bug, could someone >>> mention it in the docs somewhere? >> >> Oh, yeah. I guess you need this: >> >> select thing, string_agg(stuff, ',' order by stuff) from agg_test >> group by thing; >> >> Rather than this: >> >> select thing, string_agg(stuff order by stuff, ',') from agg_test >> group by thing; >> >> It's all kinds of not obvious to me what the second one is supposed to >> mean, but I remember this was discussed before. Perhaps we need a >> <note> somewhere about multi-argument aggregates. >> > > Yes, that works with the order clause. That's really weird! It looks > like part of the delimiter parameter, and that's undocumented, or at > least impossible to gleen from the documentation. > > This should be clarified as it looks like having ORDER BY *or* a > delimiter is supported, but not both. It's horribly unintuitive! > This is one of the very few cases where MySQL's version actually makes > more sense.
this goes from ANSI SQL standard :( - I agree, this isn't intuitive and pg can do better diagnostic now. But it has a sense. ORDER BY hasn't sense for one parameter - only for complete function, so is wrong to write ORDER BY over a some interesting parameter Regards Pavel Stehule > > Thom > > -- > Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-bugs > -- Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-bugs
