| Subject | Re: [firebird-support] Re: check constraint to enforce uniqueness |
|---|---|
| Author | Helen Borrie |
| Post date | 2005-01-04T07:04:25Z |
At 06:33 AM 4/01/2005 +0000, you wrote:
./heLen
>Thanks, Helen, Adam, but as in my check constraint, SERIALNO can beA unique constraint can contain nulls.
>null, so I can't define a unique constraint on the 4 columns since
>SERIALNO does not always have a value. In cases when SERIALNO does
>have a value, I'd like to enforce the uniqueness on the 4 columns.
>Any other way to do this if it can't be done thru a check constraint?Nothing that I would recommend.
./heLen