Re: [GENERAL] count distinct and group by

On 7 May 2015 at 11:54, Thomas Kellerer wrote: > Geoff Winkless schrieb am 07.05.2015 um 12:39: > > in Postgres (unlike MySQL) you can't order a list of values by a column > you haven't selected.​ > > Of course you can, just not when you are aggregating. > > ​Doh! I missed out that key clause :)

Re: [GENERAL] count distinct and group by

Geoff Winkless schrieb am 07.05.2015 um 12:39: > in Postgres (unlike MySQL) you can't order a list of values by a column you > haven't selected.​ Of course you can, just not when you are aggregating. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to you

Re: [GENERAL] count distinct and group by

On 7 May 2015 at 12:39, Magnus Hagander wrote: > On Thu, May 7, 2015 at 12:23 PM, Szymon Guz 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; >>

Re: [GENERAL] count distinct and group by

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; Your result set will contain one row with the count of distinct i

Re: [GENERAL] count distinct and group by

On 7 May 2015 at 11:23, Szymon Guz wrote: > Hi, > I'm not sure why there is a reason for such behaviour. > > 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

Re: [GENERAL] count distinct and group by

On Thu, May 7, 2015 at 12:23 PM, Szymon Guz 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 th

[GENERAL] count distinct and group by

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