locking data from multiple updates

[nozom]

I mentioned this a while back as food for thought but now it has cropped up in a real world scenario and I’m not 100% on a solution for it so..

Basically we want to create a system for a company that deals with contacts, jobs, products etc. This is going to be run on a LAN and with up to 5 people accessing the system at any one time.

Suppose 2 people access the same field to update it at the same time. One of them is going to go home upset because their data was wiped out by the person who hit 'submit' last.

I need to find a way to lock fields, lock access to pages if there is someone already using that page.

obviously the fact that mysql is linked to php via a non-persistent connection is the major drawback. Wither the use of a timeout function on the pages (i.e. max length of page view is 10 minutes or unless they leave the page) However all sorts of demons crop up with this.

What would be good is a way to read the headers/session info of all the users on the system. I don't think this is possible though.

anyway, some ideas would be greatly appreciated.

Thanks,
nozom

[jstarkey]

Is this what you're looking for?

http://www.mysql.com/doc/en/LOCK_TABLES.html

I'm not sure how well it will work with what you're trying to do, but maybe it's a starting point.

[nozom]

Yeah, I think that would work with a persistent connection to the database but as the thread is closed as soon as php finishes doing it's queries then starts a new thread when 'submit' is pressed.

I need to figure out a foolproof way that would do what the LOCK TABLES function does but without that persistent connection.

ta,
nozom