What is the use of a primary key?
From: Juan Pardillos <sicotom_at_eresmas.com>
Date: 20 Nov 2002 15:44:13 -0800
Message-ID: <6278687.0211201544.4578fb26_at_posting.google.com>
Hi,
Date: 20 Nov 2002 15:44:13 -0800
Message-ID: <6278687.0211201544.4578fb26_at_posting.google.com>
Hi,
I've got the following doubt: why is necessary to define a primary key?. I mean, the candidate keys must be defined as not null and unique (just the same that with the primary key), so... what's the difference?. Why is it necessary to consider a primary key instead of simply defining a set of candidate keys?.
Thanks Received on Thu Nov 21 2002 - 00:44:13 CET