Re: Primary key on one or two fields
From: Anith Sen <anith_at_bizdatasolutions.com>
Date: Thu, 14 Aug 2003 21:02:30 GMT
Message-ID: <GNS_a.99117$3o3.6880687_at_bgtnsc05-news.ops.worldnet.att.net>
Date: Thu, 14 Aug 2003 21:02:30 GMT
Message-ID: <GNS_a.99117$3o3.6880687_at_bgtnsc05-news.ops.worldnet.att.net>
Joe,
Just because it is allowed by SQL-92 does not make it logically correct. If
you look at the Foobar examples you posted, they are all under-normalized
(specifically, they are not in 2NF) and suffer from obvious update
anomalies. In a well designed schema, DEFAULTs have no place as a value for
a key.
The single row UniversalConstants table is a well-known kludge, which does not prove the need for defaults on the keys. It simply shows the INSERT statement without typing up all the values. I would be interested in seeing a real world scenario which demands the logical design to have a DEFAULT on a key.
-- - AnithReceived on Thu Aug 14 2003 - 23:02:30 CEST
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