Postgres Pro
Downloads
Home   >   mailing lists

Re: Creating a foreign key on the Union of two tables - Mailing list pgsql-sql

From Josh Berkus
Subject Re: Creating a foreign key on the Union of two tables
Date
Msg-id 200304071127.03166.josh@agliodbs.com
Whole thread Raw
In response to Creating a foreign key on the Union of two tables  (saads@umich.edu (Saad Saeed))
List pgsql-sql
Tree view 
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

pgsql-sql by date:

Previous
From: Bruno Wolff III
Date:
Subject: Re: Creating a foreign key on the Union of two tables
Next
From: Jan Wieck
Date:
Subject: Re: Creating a foreign key on the Union of two tables