Problems with Forms using views
Date: Thu, 2 Jul 1998 08:12:17 -0300
Message-ID: <6nfteu$sos$1_at_pumba.class.udg.mx>
[Quoted] We have a few forms that, after saving the changed data and trying to alter the same data again, Oracle Forms presents the folowing error message :
FRM-40654 : Record has been updated by another user. Re-query to see change.
We know that the problem is created by the fact that the data that are shown to the user are being manipulated by database triggers that, for instance, updates the primary key of the table with a value from a sequence. This way, the data that the user sees on the screen are not those that are in the table, because the trigger has changed it.
One solution we found was to re-read the table using the POST-INSERT and POST-UPDATE form triggers, replacing the on-screen values with those existing in the table, synchronizing database and form. This solution is based on a re-read using the ROWID of the table, which is a value that is always brought back from the database after an insert operation and doesn't change on an update operation.
The problem gets hairy when the block we are talking about is really based on a database VIEW, instead of being based on a table. In such case, the ROWID value is not avaliable for us if such view is based on more than one table. Thus, we cannot make the POST-INSERT and POST-UPDATE triggers to use ROWID to re-query the data.
We found an initial solution for this problem which is to use the primary key of the tables used on the view to re-query the data. This would only work if the view acting as a base for a block includes ALL columns from the primary keys of ALL tables used in the join operation by the view.
Finally, our questions are:
Is the requery operation for tables (using the ROWID) the best way to solve
this problem or there is a way to make Forms do it automatically for us?
Is the final solution the best we can get (using ALL columns from ALL PKs)?
Received on Thu Jul 02 1998 - 13:12:17 CEST