Re: help: Constaints Based on Data of Other Tables
From: Henry Harrison <hharriso_at_tdc.dircon.co.uk>
Date: 2 Nov 1994 09:13:32 GMT
Message-ID: <397l7s$4lt_at_newsgate.dircon.co.uk>
Date: 2 Nov 1994 09:13:32 GMT
Message-ID: <397l7s$4lt_at_newsgate.dircon.co.uk>
David Zlotchenko (zlotchen_at_solar.rtd.utk.edu) wrote:
: Hi,
: Do anybody know if I can use actual data of existing table for using
: in constraint on a column in another table?
This cannot be done with the current implementation of Oracle, as you have discovered. I think, if I remember rightly, that this sort of extended CHECK clause is part of the latest ANSI SQL, but it hasn't been implemented by Oracle yet.
For the moment, you will have to write a row-level BEFORE UPDATE OR INSERT trigger to raise an exception if the value entered is not appropriate.
Hope this helps,
Henry Harrison Received on Wed Nov 02 1994 - 10:13:32 CET