Re: 2 unique vals

From: Joe \ <joe_at_bftsi0.UUCP>
Date: Mon, 5 Jan 2004 11:44:00 -0800
Message-ID: <1073331846.432329@news-1.nethere.net>

"shannon" <shannon_at_nolunchmeat.com> wrote in message <news:btbsju$2nb$03$2_at_news.t-online.com>...

> in the construction of an ERD, how do we proceed when an Entity has two
> attributes with unique values?

A relation can have more than one candidate key, just as a key can be on more than one attribute, no problem. Any problems come from brain-dead ERD tools or brain-damaged DBMS products.

--
Joe Foster <mailto:jlfoster%40znet.com>  "Regged" again? <http://www.xenu.net/>
WARNING: I cannot be held responsible for the above        They're   coming  to
because  my cats have  apparently  learned to type.        take me away, ha ha!

Received on Mon Jan 05 2004 - 13:44:00 CST