Re: One-To-One Relationships
Date: Fri, 30 Nov 2007 11:06:16 -0800 (PST)
On Nov 30, 6:46 pm, paul c <toledobythe..._at_ooyah.ac> wrote:
> Tegiri Nenashi wrote:
> > On Nov 30, 8:19 am, Jan Hidders <hidd..._at_gmail.com> wrote:
> > The distinction between entities /
> >> relationships, domain objects / predicates is pretty well-established
> >> in linguistics, philosophy and logic.
> > That certainly means you can define them formally in database terms,
> > right?
> > Here is one such attempt:
> > It defines an entity as a relation (aka table:-) with a single
> > noncomposite key, and relationship as a table with composite key. Does
> > this definition pretty much exhausts the entity-relationship theory?
> > (But then BB remark was that order line is a weak entity).
> If you are accurate that an entity depends on a relation, then I'd agree
> ER theory gets exhausted pretty quickly indeed.
> Not to encourage the literalists here but an ordinary dictionary
> definition of entity, eg.,
> "The existence of something considered apart from its properties."
> suggests even more directly how superfluous ER modeling is.
<check dictionary> entity = thing</check>
<check dictionary_again> thing = entity</check> er....no.. hold on... Received on Fri Nov 30 2007 - 20:06:16 CET