John Bartow
john at winhaven.net
Wed Jul 25 15:27:19 CDT 2007
Good point. And one I glossed over while postulating my responses. I can't remember ever having a table without a PK in any RDBMS. I can't even imagine what data would be stored in an RDBMS that didn't need a PK. This is what is so befuddling to me when it comes to Outlook's contacts... -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Robert L. Stewart Sent: Wednesday, July 25, 2007 2:31 PM At 12:00 PM 7/25/2007, you wrote: >From: "jwcolby" <jwcolby at colbyconsulting.com> Whooo, there cowboy. Without a PK, how are you going to identify rows for updates and delets? Good design REQUIRES a primary key of some kind even if it is a composite key. Try updating a SQL Server table linked to MS Access that does not have a primary key. It will not let you make any change to it at all. >AND... from the perspective of the child, a FK is nothing but a pointer. >Does a table HAVE TO HAVE a PK at all? Not if it has no children. >Ergo, what matters from the child's perspective is what the PK is all >about, and that is simply a POINTER back to the parent. AND... Since a >surrogate key functions as a PK, then... A PK must be nothing but a pointer...