From: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
---|---|
To: | Greg Donald <destiney(at)gmail(dot)com> |
Cc: | pgsql-general <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: division by zero issue |
Date: | 2004-09-15 21:07:03 |
Message-ID: | 20040915210703.GB12624@svana.org |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On Wed, Sep 15, 2004 at 02:10:45PM -0500, Greg Donald wrote:
> On Wed, 15 Sep 2004 12:54:07 -0600, Guy Fraser <guy(at)incentre(dot)net> wrote:
> > This might work better.
>
> Thanks, I got it working finally. It wouldn't go without any fields
> in the second SELECT, but I added them and now it works.
>
> Where can I find docs for the 'as intermediate' part of this query. I
> never heard of it and can't seem to find it in the manual other than
> it's listing in the SQL keywords table. I see what it does but still
> want to read the docs about it.
It's a called subquery. Everything in the brackets is a query which
produces a result and is aliased to the name "intermediate". The outer
query can then use it as a source table like any other table.
Ofcourse, optimisation might mean it gets optimised away, but that's
the basic idea...
--
Martijn van Oosterhout <kleptog(at)svana(dot)org> http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.
From | Date | Subject | |
---|---|---|---|
Next Message | daniel | 2004-09-15 21:25:24 | Re: psql + autocommit |
Previous Message | Martijn van Oosterhout | 2004-09-15 20:59:59 | Re: what is flushed? |