Re: Problem with subquery in CHECK constraint.

CONSTRAINT TYPE_CD_OK CHECK (EXISTS (SELECT 1 FROM XREF WHERE         XREF_GROUP = 'CUST_TYPE' AND        XREF_CD =
TYPE_CD)
)


> There seems to be more serious problems.
> 1) The constraint is not only for the defined table but also for referenced
>     tables in the subquery.

I don't understand what you mean -- the constraint only
constrains 1 column in one table...

> 2) There should be some standard lock mechanism for the range restricted
>     by the subquery.
> 
> I'm suspicious that we should/could implement constraints other than
> column constraints.

Again, I don't fully understand what you're saying; but I
have successfully implemented the constraint using a user
defined function.

Niall