Oracle Forms Developer – Form Builder Reference, Volume 1

Pre-Update trigger
Description
Fires during the Post and Commit Transactions process, before a row is updated. It fires once for each
record that is marked for update.
Definition Level form or block
Legal Commands
SELECT statements, DML statements (DELETE, INSERT, UPDATE), unrestricted built-ins
Enter Query Mode no
Usage Notes
Use a Pre-Update trigger to audit transactions.
On Failure
Form Builder performs the following steps when the Pre-Update trigger fails:
• sets the error location
• rolls back to the most recent savepoint
Fires In
Post and Commit Transactions
See Process Flowcharts
Pre-Update trigger examples
Example
The following example writes a row into an Audit Table showing old discount and new discount for a
given customer, including timestamp and username making the change.
DECLARE
old_discount NUMBER;
new_discount NUMBER := :Customer.Discount_Pct;
oper_desc VARCHAR2(80);
CURSOR old_value IS SELECT discount_pct FROM customer
WHERE CustId = :Customer.CustId;
BEGIN
/*
** Fetch the old value of discount percentage from the
** database by CustomerId. We need to do this since the
** value of :Customer.Discount_Pct will be the *new* value
** we’re getting ready to commit and we want to record for
** posterity the old and new values. We could use
** SELECT...INTO but choose an explicit cursor for
** efficiency.
*/
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