SQL Update Trigger not working as expected - oracle

Question

I have an update trigger on my oracle table..but seems like it's not working..Schema under which triggers and table created is HR
CREATE OR REPLACE Trigger TR_FinlStatAssetDesignation_U
BEFORE update
on FINLSTATASSETDESIGNATION FOR EACH ROW
DECLARE
v_AtDateTime TIMESTAMP(3);
v_LogOperation NUMBER(3,0);
v_UserName VARCHAR2(255);
v_AppName VARCHAR2(255);
SWV_error NUMBER(10,0) DEFAULT 0;
BEGIN
begin
select USERNAME INTO v_UserName FROM v$session WHERE (audsid = SYS_CONTEXT('userenv','sessionid')) AND ROWNUM <=1;
EXCEPTION
WHEN NO_DATA_FOUND THEN
NULL;
end;
SELECT program INTO v_AppName FROM v$session WHERE audsid=userenv('sessionid');
if (LENGTH(v_AppName) = 0) then
v_AppName := 'Unknown';
end if;
SELECT SYSTIMESTAMP INTO v_AtDateTime FROM dual;
if UPDATING('FinlStatAssetDesignation') then
RAISE_APPLICATION_ERROR(-20000,'Invalid attempt to update OID FinlStatAssetDesignation in FinlStatAssetDesignation');
/*
ROLLBACK */
return;
end if;
if not UPDATING('UpdDate') then
SWV_error := 0;
begin
UPDATE FinlStatAssetDesignation a SET(UpdDate) =(SELECT distinct v_AtDateTime FROM dual where a.FinlStatAssetDesignation = :NEW.FinlStatAssetDesignation)
WHERE ROWID IN(SELECT a.ROWID FROM FinlStatAssetDesignation a where a.FinlStatAssetDesignation = :NEW.FinlStatAssetDesignation);
EXCEPTION
WHEN OTHERS THEN
SWV_error := SQLCODE;
end;
if SWV_error <> 0 then
/*
ROLLBACK */
return;
In this trigger.. second part i.e below is not working of trigger..please help....it is not updating the timestamp in upddate column
SQL> select * from finlstatassetdesignation;
FINLSTATAS FINLSTATASSETDESIGNATIONDESC UPDOPERATION
---------- -------------------------------------------------- ------------
UPDDATE
---------------------------------------------------------------------------
one19 anyt 0
hinh
01-JAN-17 08.00.00.000000 AM
SQL> update finlstatassetdesignation set finlstatassetdesignationdesc ='nothing';
1 row updated.
SQL> select * From finlstatassetdesignation;
FINLSTATAS FINLSTATASSETDESIGNATIONDESC UPDOPERATION
---------- -------------------------------------------------- ------------
UPDDATE
---------------------------------------------------------------------------
one19 nothing 0
01-JAN-17 08.00.00.000000 AM

Answer 1

What are you trying to accomplish in the ON INSERT trigger? From your comment of
I still can insert a row as user "hello"..hence trigger is not working..
you seem to want to prevent a user named HELLO from being added - but in your trigger code if a username of HELLO is found you simply return from the trigger. That doesn't accomplish anything. To signal to the system that you don't want the INSERT to proceed you must raise an exception in your trigger. For example:
CREATE OR REPLACE Trigger TR_FinlStatAssetDesignation_I
BEFORE Insert on FINLSTATASSETDESIGNATION
BEGIN
if USER = 'HELLO' or USER = 'SYSTEM' then
RAISE_APPLICATION_ERROR(-20000, 'Invalid user in TR_FinlStatAssetDesignation_I');
end if;
END TR_FinlStatAssetDesignation_I;
Raising an exception in this manner will prevent the INSERT from proceeding to successful completion. Your code is responsible for providing an appropriate error handler.
Best of luck.