Re: [SQL] Slashdot Query

It looks to me like that solution would simply be a list of all the
categories (assuming there is a story in every category). What I want is
the 5 unique categories applying to the most recent stories.

"Jackson, DeJuan" wrote:
> 
>         Is it me or does this query actually make any sense???
>         Is story.datetime a column in your table?

yes

> 
>         You might be able to rewrite this query.  I don't know if the
> ordering you were trying for is needed, but
> 
>                 SELECT oid, title, image FROM category*
>                 WHERE EXISTS(SELECT 1 FROM story
>                         WHERE story.approved AND story.category =
> category.oid);
> 
>         should give you the same information.
> 
>         Hope this helps,
>                 -DEJ
> 
> > Chris Bitmead <chris.bitmead@bigfoot.com> writes:
> > > SELECT category.oid, category.title, category.image FROM story,
> > > category* WHERE story.category = category.oid AND story.approved GROUP
> > > BY category.oid, category.title, category.image ORDER BY min(datetime);
> > > pqReadData() -- backend closed the channel unexpectedly.
> > >         This probably means the backend terminated abnormally
> > >         before or while processing the request.
> > > We have lost the connection to the backend, so further processing is
> > > impossible.  Terminating.
> >
> > This is a known problem --- see my pghackers email of a few days ago,
> > "inherited GROUP BY is busted".
> >
> >                       regards, tom lane