Re: existence question

From: Volker Hetzer <volker.hetzer_at_ieee.org>
Date: Wed, 21 Jul 2004 16:36:36 +0200
Message-ID: <cdlv1k$k7a$1@nntp.fujitsu-siemens.com>

"Jeff Kish" <jeff.kish_at_mro.com> schrieb im Newsbeitrag news:brusf0hcl6oi8e9a390c7k815gi0vjelgl_at_4ax.com...
> Greetings.
>
> Can someone help me out here?
> I have a table. with a unique index across five columns (c1, c2, c3, c4, c5.
>
> I was trying to figure out if there was a way to form an sql where clause that
> would tell me if a certain business rule would be violated.
>
> The rule says, for a given (c1 c2), if you have any rows that have c4 and c5
> null, then you can't have any other rows for that (c1 c2) which have a not
> null c4 or a not null c5.
>
> I'm a bit out of practice.

This sounds to me like if it should be redesigned in at least two tables because it's not normalized.

Greetings!
Volker Received on Wed Jul 21 2004 - 09:36:36 CDT