On 7 May 2015 at 12:39, Magnus Hagander <mag...@hagander.net> wrote: > 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.. > > Oh, right. Thanks. I haven't noticed that there is no id column in the dataset.
thanks, Szymon
