Locking in JClient applications

Question

Hi all,
I've some questions / thoughts about the use of locking for JClient based applications.
First of all the locking mode. What would be the best way to go? Pessimistic locking makes sure nobody ever loses his/her work (because you can never start changing a row if another user is already doing so), but I got the feeling it's much harder to catch locking errors and doing something usefull with it when using pessimistic locking. For example, if you use a ViewObject with some detail ViewObject's beneath and start to change an attribute of one of the detail rows and someone else is already editting the same row BC4J will throw a lock exception. But I actually don't want the user to be able to edit the row in the first place if it is already locked. You can use an association to automatically lock the master row too, but this only happens as soon as someone has started editting one of the detail rows. At that time multiple users can already have looked at the master/detail rows in edit mode. What I actually want is show them a read-only version of the master and detail rows as soon as one of the users loaded the master/detail rows in edit mode. The only way I can think of doing this is manually lock the rows as soon as the first user it opening the edit screen (without having changed anything yet). Or does anyone know of a better way of doing this? And is there an easy way to use the BC4J/JClient bindings to make all fields read-only if the rows are being editted by another user?
Optimistic locking is another way to go. The user gets only an error when committing if someone else changed the row earlier on. The user can then choose to save anyway or rollback and loose his/her work. The latter is a bit of a shame ofcourse, but in practise this might not happen often.
Does anyone have any other tips or suggestions for using locking in JClient applications?
Regards,
Peter

Answer 1

Hi vinu,
You can use these functional modules....
<b>BAL_DB_ENQUEUE</b>----
>Lock log
<b>ENQUEUE_ESFUNCTION</b>---->Lock an abap program so that it
                       cannot be executed.
<b>1. Example code for Database Locking...</b>
http://www.sapdevelopment.co.uk/dictionary/lock_enqueue.htm
<b>2. Help.Sap.Com</b>
http://help.sap.com/saphelp_nw04/helpdata/en/7b/f9813712f7434be10000009b38f8cf/content.htm
Hope it helps.
Regards,
Maheswaran.B
Message was edited by: Maheswaran B