Re: Integrity constraint
Date: Tue, 03 Feb 2009 15:12:57 +0100
> I looke up De Morgans law and accordingly, the English translation is
> "This claim asserts that A is false and B is false."
> This is exactly what I want. I want everything in X that does not
> exist in Y nor in Z. So, we would only get results coming into the
> final resultset as:
> Give me all the records that exist in X after ensuring the rows with
> the same id do not exist in Y and Z.
Sorry, I misunderstood, my failure.
I thought you want to delete records after ensuring that the same id does not exist in both tables, or to be more specific "NOT (id IN (SELECT id FROM y) AND id IN (SELECT id FROM z))". So, I thought too fast and were totally wrong.
How is Y_FK defined?
Michael Received on Tue Feb 03 2009 - 08:12:57 CST