On Fri, Jul 17, 2009 at 11:51 AM, tedd<tedd.sperling@xxxxxxxxx> wrote: > At 11:12 AM -0400 7/17/09, Jason Pruim wrote: >> >> Hi everyone! >> >> So some of you may have noticed that I have been away for quite awhile... >> Been trying to get settled (Moved across the country) and getting a job. >> >> And now that that is done I have a question about a project that I might >> be doing for my current employer and want to do it properly. >> >> If all goes through, I'll be writing an online database that upwards of 10 >> people will be using at various times through out the day. Basically, in a >> form they fill out a model number, customer name, phone number etc. etc.. >> And then submit the form. After submitting they need to write the log number >> on some paperwork. If I have 2 people submit the form at the same time, I'm >> thinking I could end up with a race condition and they might get the wrong >> log number (The log number is simply a consecutive record number) >> >> Do I need to be reading up on locking tables/rows? Or in my situation as >> I've briefly described it do I not have to worry about it? Or is there a >> third door with the magic bullet that will solve all my problems? :) >> >> Any advice is greatly appreciated as always, RTFMing is good as well, as >> long as M is defined :) >> >> I'm not afraid of google either, just need the right terms to hit it with >> so I don't go into "search overload" as the commercials for a rival search >> engine claim :) >> >> Thanks Everyone! > > Jason: > > Welcome back. > > Clearly if you have two or more people checkout the same record at the same > time and each edits the record then you ARE going to have problems when each > updates the record. > > You can solve this problem by using transactions -- here's a link: > > http://dev.mysql.com/doc/refman/5.0/en/lock-tables-and-transactions.html > > When someone is editing a record, you also need to be able to show the next > person(s) that the record they want is currently busy and not available. > However, I'm not sure as to how to notify the next user that the table is > locked via php. Perhaps a table status might provide that information. If > so, then use that to notify the next user. > > As for your log of activity, just create a another record (with an > auto_increment index) in your activity log table and update that record with > the data you need to record, such as user id, timestamp, what record they > accessed and whatever else you want after the transaction is completed. > > Cheers, > > tedd > > -- > ------- > http://sperling.com http://ancientstones.com http://earthstones.com > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > As a further note to tedd's reply on transactions, you will need to use the INNODB engine in mysql should you want to use transactions. Transactions here are done a row locking level not table so you should have fewer issues. -- Bastien Cat, the other other white meat -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
