You do this so that referential integrity is enforced by the database i.e. you don't end up with recs in one table with no corresponding rec in another.
-----Original Message----- From: Michael Kear [mailto:[EMAIL PROTECTED]] Sent: 27 September 2002 16:54 To: SQL Subject: Why External keys? Sorry if this is such a basic question as to be stupid, but why do you sometimes have foreign keys? I've looked at MS's Books Online, but that only tells me how to do it, not why I'd want to, which is typical of Microsoft's documentation. On my tables in MS SQL2000, I typically have an primary key ID field which is int, identity, 1, 1 which works fine as far as I've gone, which I'll admit isn't all that advanced. There is obviously an advantage to having a foreign key, because people do it, but I'm afraid I am too much a learner to know what the advantage is. Can someone give me a quick explanation of why and/or when its better not to have the key as a field in the table itself? Cheers, Mike Kear Windsor, NSW, Australia AFP WebWorks ______________________________________________________________________ Get the mailserver that powers this list at http://www.coolfusion.com Archives: http://www.mail-archive.com/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
