Re: One-To-One Relationships

From: Tegiri Nenashi <>
Date: Fri, 30 Nov 2007 14:26:55 -0800 (PST)
Message-ID: <>

On Nov 30, 1:44 pm, Jan Hidders <> wrote:
> On 30 nov, 19:45, "David Cressey" <> wrote:
> > Here's the way I would try to unify the two concepts. Relationships can be
> > binary, ternary, and so on, depending on the number of entities involved in
> > a single instance of the relationship. How about considering an entity a
> > "unary relationship"?
> Minor nitpick: that unary relation is the entity type (or class or
> whatever you want to call it), not the entity itself, which is of
> course the thing for which the unary relationship holds. Otherwise you
> are of course completely correct.

So the matter reduces to relation attribute counting? Then, what additional insight the "new" concepts of "entities" and "relationship" add to the "relation" and "domain"? Received on Fri Nov 30 2007 - 23:26:55 CET

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