Re: string_agg delimiter having no effect with order by - Mailing list pgsql-bugs

On Wed, Aug 4, 2010 at 6:03 AM, Thom Brown <thom@linux.com> wrote:
> Actually, this rings a bell. =A0I think this may have been raised
> before, something to do with the delimiter being accepted as one of
> the order by values. =A0If 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.

--=20
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise Postgres Company