Re: existence question

From: Daniel Morgan <damorgan_at_x.washington.edu>
Date: Wed, 21 Jul 2004 22:13:46 -0700
Message-ID: <1090473251.707878@yasure>

Jeff Kish wrote:

> 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.
>
>
> Thanks
> Jeff
> Jeff Kish

Tom Kyte has had a lot to say on the subject of enforcing this type of business rules so you might check at http://asktom.oracle.com.

I wouldn't attempt to enforce this without a BEFORE-INSERT or UPDATE trigger.

Daniel Morgan Received on Thu Jul 22 2004 - 00:13:46 CDT