Scott Marcus
marcus at tsstech.com
Wed Jun 16 06:09:42 CDT 2004
<< There is no guarantee that your club memebrship, library card etc ID was not used previously for another member. There is also no guarantee that any "natural key" has not been used previously or will be used in the future by some distinct entity. Scott Marcus TSS Technologies, Inc. marcus at tsstech.com (513) 772-7000 -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Stuart McLachlan Sent: Tuesday, June 15, 2004 7:28 PM To: Access Developers discussion and problem solving Subject: RE: [AccessD] OT: The Great Primary Debate On 15 Jun 2004 at 10:18, Francis Harvey wrote: > > You also have an inordinate amount of faith that people aren't using > the surrogate key except in the database. I don't know about you, but > I have no doubt that my database generated movie rental id, library > card id, etc. are not being shadowed by an internal surrogate key. > They have actually given me a card with the key on it, and it > definitely isn't formed by collapsing other attributes to form an > artificial key. It happens. > If those systems are using an internally derived Primary Key and using that same value as your assigned library card ID or movie rental ID they are poorly designed for all the reasons that have been discussed ad nauseum over the last several iterations of this debate. A common way to generate these sorts of "membership ID"s is to use the next *currently available* number. There is no guarantee that your club memebrship, library card etc ID was not used previously for another member. -- Lexacorp Ltd http://www.lexacorp.com.pg Information Technology Consultancy, Software Development,System Support. -- _______________________________________________ AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com