NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/comp/database/oracle/2977

Text File | 1993-01-28 | 1.7 KB | 41 lines

Newsgroups: comp.databases.oracle
Path: sparky!uunet!math.fu-berlin.de!news.belwue.de!ifi!scheidjs
From: [e-mail] (Johannes Scheidler)
Subject: Locking under SQL*Forms 3.0
Message-ID: <[e-mail]>
Keywords: Lock
Sender: [e-mail]
Organization: Informatik, Uni Stuttgart, Germany
Date: Thu, 28 Jan 1993 09:58:43 GMT
Lines: 29

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 :

[e-mail]

Thanks