Thanks for the reply Manual. The updating IS done with one single query - but the problem is that if two people are editing the same car, the second update will overwrite the first. Not a huge problem - and the chance of it happening is almost nil - but there is still the possibility.. Changing databases seems a little extreme - and not possible with our web host. Tom At 20:03 10/07/2001 -0300, you wrote: >Hello, > >Tom Peck wrote: > > > > Hi > > > > The company I work for has recently developed a Car Dealer type site, which > > acts as a large on-line used car yard. Currently the MySQL database > > holding the cars is added too / edited / deleted by one person employed for > > the job - but we hope to expand to allow the Dealers themselves admin > > rights to their on-line cars. > > > > I have begun development of a Dealer Admin area - but have a couple of > > questions regarding this: > > > > 1) Would any sort of Table Locking be needed for this - for example if > > two people were trying to update the same car, at the same time etc etc.. > >No, if updating is done with a single query. > > > > 2) If yes, is there any on-line documentation on this? > > 3) What other problems could arise if this was implemented? > >It depends on what you really want to do. > >Anyway, MySQL has LOCK TABLES but I don't recommend to use them without >proper because you inadvertdly may leave the database locked. The latest >versions also support transactions. It's a bit awkward but it works, >although the recommendation is the same. > >Maybe you want to try other databases that handle transactions more >efficiently like Oracle, or PostgreSQL if you can't afford a commercial >database. > >If you are not sure about switching to other databases, you may want to >try Metabase which is a database abstraction package that lets you write >portable database applications. That way, you may switch (or not) to >another database later without changing your application code. > >Metabase is free and is available here: > >http://phpclasses.UpperDesign.com/browse.html/package/20 > >Manuel Lemos > >-- >PHP Database Mailing List (http://www.php.net/) >To unsubscribe, e-mail: [EMAIL PROTECTED] >For additional commands, e-mail: [EMAIL PROTECTED] >To contact the list administrators, e-mail: [EMAIL PROTECTED] -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]