Re: Forcing uniqueness using triggers, ORA-4091

From: Brian Rasmusson <brian-r_at_post3.tele.dk>
Date: Mon, 04 Jan 1999 09:10:56 +0100
Message-ID: <36907790.A7DB8D1E@post3.tele.dk>

Hi Jonathan,

> I had to deal with a situation like this recently. When you
> have a null varchar_col1, you don't want to bother with the
> uniqueness check, right? I hope that's right. That's what I
> understood.

Exactly.

> My solution to this problem was to create a unique
> constraint on a single field. That way, null values are
> ignored. First add a new column to your table:

Yes, that's what i feared ;-) I had hoped to avoid this extra column, but it seems like i cannot avoid it after all. Thanks for your help!

Brian Received on Mon Jan 04 1999 - 02:10:56 CST