Re: How to ensure data consistency?
From: --CELKO-- <jcelko212_at_earthlink.net>
Date: 9 Sep 2004 08:57:46 -0700
Message-ID: <18c7b3c2.0409090757.4133eee7_at_posting.google.com>
Date: 9 Sep 2004 08:57:46 -0700
Message-ID: <18c7b3c2.0409090757.4133eee7_at_posting.google.com>
>> there still is the problem that the main table may contain entries
for which there are no [rows in] subtables. <<
In intermediate SQL-92, all table level constraints are TRUE for an empty table, so you need to have full SQL-92 and use a cross table constraint. That would be either a CREATE ASSERTION statement or a CHECK() that has a predicate that references the other table. Received on Thu Sep 09 2004 - 17:57:46 CEST