Re: One-To-One Relationships

"Tegiri Nenashi" <TegiriNenashi_at_gmail.com> wrote in message news:9b2d4a13-aa6e-49c9-9b05-26cae59155d8_at_a35g2000prf.googlegroups.com...
> 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:
> http://arxiv.org/PS_cache/arxiv/pdf/0710/0710.2083v1.pdf
> 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?
>

Not good. An entity is not a relation. The data stored in a relation describes an entity or a relationship among entities. The difference between "is" and "describes" is important. Received on Fri Nov 30 2007 - 19:38:39 CET