Mutating table error

Hello,

I have a very simple table, and want to create a trigger that updates the date column entry (with the current date), whenever a row gets modified.
Is there a simple way of fixing this, or would I have to create 3 extra triggers, a package, etc., as described in most posts about mutating table errors?
Could you please explain to me WHY this error happens here (I have not been able to find a clear explanation of what causes them)?

create table mvkTest
(bukva char(5),
kogda date);

insert into mvkTest
values('aaa', sysdate);
insert into mvkTest
values('bbb', sysdate);

create or replace trigger test_Trigger
after update on mvkTest
for each row
begin update mvkTest
set kogda = sysdate;
end;
/

update mvkTest
set bukva = 'ccc'
where bukva = 'aaa';

=======>>>>>>

update mvkTest

       *
ERROR at line 1:
ORA-04091: table DTI.MVKTEST is mutating, trigger/function may not see it
ORA-06512: at "DTI.TEST_TRIGGER", line 1 ORA-04088: error during execution of trigger 'DTI.TEST_TRIGGER'

Thank you,
G. Received on Tue Feb 17 2004 - 20:42:11 CET