Re: Creating a foreign key on the Union of two tables

Saad,

> I have 2 tables "A" and "B" in mySQL. They both have an attribute 'id'
> which is unique between the 2 tables. I want the union of these 2
> attributes to be a foreign key in a 3rd table "C". How do I specify
> this constraing in sql (mySQL) in table C? And for complex reasons I
> cannot merge the 2 tables A and B.

IMHO, you cannot do this in MySQL.  How about upgrading to PostgreSQL?  Then
we can help you.

--
-Josh BerkusAglio Database SolutionsSan Francisco