On Fri, Nov 14, 2008 at 9:58 AM, <ceo@xxxxxxxxx> wrote: > > > okay I want to pull an integer from a database called confirm_number, > > add 1 and repost it back to the database > > No, you don't want to do that. > :-) > > You are introducing a race condition between TWO users who hit the same > page at the same time. > > They each get, say, 42, and they each put back 43, but one of them should > have been 44. > > What you WANT to do is this: > update contacts set confirm_number = confirm_number + 1 order by contact > desc limit 1 > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > yep, our current app, designed by 'brighter minds' than mine, refused to make these auto numbers and now we have problems caused by the race condition. -- Bastien Cat, the other other white meat
