On Thu, May 7, 2015 at 12:23 PM, Szymon Guz <mabew...@gmail.com> wrote:
> Hi, > I'm not sure why there is a reason for such behaviour. > > For this table: > > create table bg(id serial primary key, t text); > > This works: > > select count(id) from bg; > > This works: > > select count(distinct id) from bg; > > And this doesn't: > > select count(distinct id) from bg order by id; > ERROR: column "bg.id" must appear in the GROUP BY clause or be used in > an aggregate function > LINE 1: select count(distinct id) from bg order by id; > > There is no "id" column in the returned dataset to order by. You are just returning one value, how would it be ordered? (and that row has a column named "count" - but you can alias it to SELECT count(distinct id) AS id FROM bg ORDER BY id - it just makes no sense to order a single row.. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/
