Re: Record Locking using web forms ?

> Atif Ahmad Khan <aak2_at_Ra.MsState.Edu> wrote in article
> <aak2.842442903_at_Isis.MsState.Edu>...
> > Record locking using web forms ?
> >
> > I have been assigned to find a solution to this problem. We are
 developing
> > an application that will let employees access certain databases over
 the web
> > using standard forms. Our problem is that if 2 users accessed the
 data using
> > web based forms and changed it, the one that commits it last will
 overwrite
> > the changes made by the other guy.
> >

Your server would have to maintain transaction context state between client requests. The state of the transaction would have to maintain persistence until COMMIT or ROLLBACK and finally, the lock list is part of the transaction context.

One possible solution is that each client is given a unique id by the server at login and then the client uses this id for every message dispatched to the server. The server can index into a transaction context array using this id to get at the client's persistent transaction context and more specifically, to get at the transactions lock list.

I highly recommend Jim Gray/Andreas Reuter's book titled "Transaction Processing: Concepts and Techniques".

Regards,

Matt

-- 
==================================================

Matt Houseman                       Arbor Software
mhouseman_at_arborsoft.com             408.541.4408

"...honest to the point of recklessness,
    self-centered to the extreme..."

==================================================