Re: Generic or specific
From: Mark Preston <mark_at_mpreston.demon.co.uk>
Date: 2000/04/13
Message-ID: <38f49205.1074818_at_news.demon.co.uk>#1/1
Date: 2000/04/13
Message-ID: <38f49205.1074818_at_news.demon.co.uk>#1/1
On Tue, 11 Apr 2000 16:51:50 +0300, gkiourtas michail <michgkio_at_otenet.gr> wrote:
>For a lending library project:
>a) Is book and a copy of this book an unary relationship?
How many copies of a book can there be? More than one, of course, and
so the relationship cannot be unary.
>b) Is book a generic entity and a copy of it a specific entity?
'Books' is a generic entity and each book a specific example of such
an entity.
-- Mark A Preston BSc, FIAP The Magpie's Nest mark_at_mpreston.demon.co.ukReceived on Thu Apr 13 2000 - 00:00:00 CEST