Michael, why do you need to link de manufacturer table with de product table? I think that you have to clarify the design of your db and your business rules first... for instance, if you have to reuse the IDs (the barcode and de manufa cturer ID), then you will create new tables in order to preserve your history (I supouse that it will be interesting to know that in 1999 the transactions of the ID 111 corresponds to Michael!!).
Fernando Bernain Senior A Business Process Outsourcing KPMG Argentina Tel: 54 11 4316 5754 Fax: 54 11 4316 5734 [EMAIL PROTECTED] -----Original Message----- From: Michael Conway [mailto:[EMAIL PROTECTED]] Sent: Saturday, December 21, 2002 9:15 PM To: [EMAIL PROTECTED] Subject: [PHP-DB] Questions regarding primary keys, updates, and autoincrement I have been working on an e-business project and have a product table and manufacturer table that are linked via barcode and a manufacturer ID (both primary keys in the tables mentioned). For now, I have been setting the manufacturer's ID manually, primarily for that rare instance where a manufacturer and its products are dropped from the database, but the number should be reused. Is it better or possible (without complications) to use autoincrement and simply delete the product information and manufacturer information while leaving the ID column intact for a later update operation with a new manufacturer and its products? I suppose only one table (the linking table?) should be set to autoincrement and that ID number used to populate the remaining tables depending upon that number for insert operations. The code is probably simple, but my head is already swimming. I suppose what I am looking for is "best practice" advice from seasoned db administrators. A second question, which may be moot if autoincrement is the best way to go, is why I keep getting an duplicate key error despite using IGNORE in my mysql update scripts. Keep in mind that the update is completed anyway (even without using IGNORE) but the abort prevents an acknowledgement script which is essential in unregistering sessions crucial in future update operations. Thanks. Michael Conway [EMAIL PROTECTED] (703) 968-8875 Email Disclaimer The information in this email is confidential and may be legally privileged. It is intended solely for the addressee. Access to this email by anyone else is unauthorised. If you are not the intended recipient, any disclosure, copying, distribution or any action taken or omitted to be taken in reliance on it, is prohibited and may be unlawful. When addressed to our clients any opinions or advice contained in this email are subject to the terms and conditions expressed in the governing KPMG client engagement letter. -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
