On Fri, 2009-07-17 at 14:01 -0400, Bastien Koert wrote: > On Fri, Jul 17, 2009 at 1:54 PM, Jason Pruim<jason@xxxxxxxxxxxxxx> wrote: > > > > On Jul 17, 2009, at 11:56 AM, Bastien Koert wrote: > > > >> 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. > > > > I also just found out that unless I can convince them to host it off site, > > it'll be on a windows machine.... So php & mssql... Does that change alot? > > > > To answer some of the other questions the Log number is currently just an > > auto incrementing consuctive number. So an auto+increment would work > > perfectly. What I'm trying to avoid is: > > > > User1 > > User2 > > > > User1 submits to log number 12345 > > User2 submits to log number 12346 > > > > User1 is told their log number is 12346 > > User2 is told their log number is 12346 > > > > But User1 & User2 are on different computers... And if it's as easy as using > > the equivelant for: SELECT * FROM table WHERE UserID="User1" ORDER BY > > lognumber desc LIMIT 1; Then I'm good... I know how to proceed with writing > > it... Just need to figure out how to bill/sell it! ;) > > > > > > > > > > -- > > PHP General Mailing List (http://www.php.net/) > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > MSSQL doesn't allow limit, but you can do a > > select top 1 * from table [where] [order by lognumber desc] > > -- > > Bastien > > Cat, the other other white meat > I believe more recent versions of MSSQL allow the LIMIT clause, but what's wrong with MySQL on Windows? Thanks Ash www.ashleysheridan.co.uk -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
