Re: Removing simliar elements from a set

On 26 Sep 2003 at 16:55, Josh Berkus wrote:

> Dan,
>
> > I'm trying to remove items from a set which are similar to items in
> > another set.
> <snip>
>
> > In short, we remove all items from MASTER which are under the directories
> > specified in MATCHES.
>
> from your example, you are trying to remove all directories which do *not*
> match. What do you want, exactly?

Josh and I talked on IRC about this.

This is the result set I want:

/ports/Mk/bsd.python.mk

I want things from MASTER which do not match things in MATCHES.

Josh suggested this:

SELECT *
FROM master
WHERE NOT EXISTS (
SELECT *
FROM matches
WHERE master.pathname LIKE (matches.pathname || '/%'));

Cheers.
--
Dan Langille : http://www.langille.org/