Re: Help with SQL constraint

From: DA Morgan <damorgan_at_psoug.org>
Date: Thu, 15 Feb 2007 08:41:35 -0800
Message-ID: <1171557692.897785@bubbleator.drizzle.com>

Arto Viitanen wrote:

> dean wrote:

>> Hello all,
>>
>> A table T has 2 fields, one (L) holding letters 'Y' and 'N', and one
>> (X) holding numbers. Is there a (non trigger) constraint such that for
>> L='N' (and only this letter) the numbers must be unique? Records
>> where L='Y' do not have to be unique.
>>
>> (I need to join another table to the L='N' group of records, and the
>> join must be key-preserved).
>>
>> Cheers,
>>
>> Dean
>>

> 
> Why not divide the table to two tables, one containing to constraint
> (with UNIQUE) and the other not. Then make a view using UNION for the
> original table.

Report writers will love you.

The OP still hasn't answered the question: "What's wrong with triggers."

Why break an application to solve a problem we still don't understand?

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org

Received on Thu Feb 15 2007 - 10:41:35 CST