Locking under SQL*Forms 3.0

From: Johannes Scheidler <scheidjs_at_mickey.informatik.uni-stuttgart.de>
Date: Thu, 28 Jan 1993 09:58:43 GMT
Message-ID: <1993Jan28.095843.1238_at_ifi.informatik.uni-stuttgart.de>


With default locking in SQL*Forms 3.0 (if you make an query with FOR_UPDATE and NOWAIT option), the record is locked, when you change its value, as late as possible. When the record is already locked, you get the message : Attempt to preserve record for update or delete. Press CONTROL-C to cancel...

The reaction of the CTRL-C is very slow (it can take up to minutes). Is it possible to avoid this message and then giving the user a message without waiting for the CTRL-C ? In my own programs I can make a Lock with NOWAIT option and then I get an error, if the lock is used by another process, but a simple Select in Forms does never make any locks, even if I made an explicit lock statement.

The other way is never to lock anything and always get the message : Record updated by another user, plese requery.

Is there any use of the ON-LOCK-Trigger? Is it possible to make an explicit lock (e.g. row exclusive) at the time of the query ?
How can I lock other tables which contains references on the current visible data and must be updated/deleted with the current record ?

We need an easy way (for many Forms) to implement multi-user-features without any visible messages for the user (or simply no waiting for CTRL-C). If you have solved this problems please mail me your solution to :

hannes%tuatara_at_Germany.EU.net

Thanks Received on Thu Jan 28 1993 - 10:58:43 CET

Original text of this message