Re: Optimistic Locking

Or you include all the columns with the prior values in the where clause and if you don't update a row then someone changed the data underneath you. Advantage of this is you don't have to worry about someone changing data and forgetting to update the timestamp.
Jim

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"viki" <vikash_at_dog.com> wrote in message
news:f01186ed.0305080812.7808870f_at_posting.google.com...


> While working on a web-based application, there is no straight forward


> means to lock records. The reason for this is the statelessness of web

> based applications. The web browser sends a request and the web server

> responds to the request. The transaction is restricted to this

> duration and all locks holds only within this transaction.

>

> The only way in which you can achieve locking in such a system is by

> what is called as optimistic locking, where you maintain a time stamp

> column (date and time of last update) in every table. When a page is

> requested, the date and time of last update of the record is also

> sent. Now, when the user updates the record, check if the time stamp

> of the record has changed. If yes you can throw an error.

>

> I guess this should work in you case as well.

>

> Cheers

> Viki