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(dot)bitmead(at)bigfoot(dot)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