Re: Database design, Keys and some other things
From: x <x_at_not-exists.org>
Date: Tue, 27 Sep 2005 17:02:17 +0300
Message-ID: <dhbjde$tru$1_at_domitilla.aioe.org>
Date: Tue, 27 Sep 2005 17:02:17 +0300
Message-ID: <dhbjde$tru$1_at_domitilla.aioe.org>
"David Cressey" <david.cressey_at_earthlink.net> wrote in message news:DQa_e.4897$QE1.1289_at_newsread2.news.atl.earthlink.net...
> If I'm creating a data model for a personnel system, I'm going to model
> "date of birth" as an attribute of a person.
> If I'm creating a data model for a maternity ward, I'm going to model
"date
> of birth" as an attribute of a birth.
> The person(s) born would inherit the attribute due to their relationship
to
> the birth.
Then, after the translation of this model to the relational model, the date become the attribute of some relation (not of some entity) and the problem "which is the entity of this attribute ?" is solved. Received on Tue Sep 27 2005 - 16:02:17 CEST