Re: Problems with NULL-values in foreign key Fields?
From: Nelson Ricardo <nelson_at_nelsonricardo.com>
Date: 29 May 2002 13:13:00 -0700
Message-ID: <1c37187b.0205291213.24752ff9_at_posting.google.com>
Date: 29 May 2002 13:13:00 -0700
Message-ID: <1c37187b.0205291213.24752ff9_at_posting.google.com>
d.foerderer_at_zi.unizh.ch (Daniel Foerderer) wrote in message news:<c6e754d2.0205290550.453040bb_at_posting.google.com>...
> I had a problem with the manager of my group because he said that I
> have to avoid foreign key fields which can be Null in database design.
> In my books about database design they write that null values in
> foreign key fields are ok.
Having null foreign keys is perfectly OK. The only issue you may come across is when joining on those columns. Unless you use an outer join, you may omit results which should have been returned (because they join cannot find a match). Received on Wed May 29 2002 - 22:13:00 CEST