Mutating table with old and new ... only

Hello,

I have been told that something like:

create trigger triggername
before update of ROW on TABLE
for each row
when (old.ROW = a and new.ROW = b)
begin
  :new.ROW := :old.ROW;
  .... message "a could not be updated with b" end;
/

would cause the mutating table error. Certainly I have tried it out and did not receive this error. From my knowledge new and old are just "copies" and since I am not accessing the table/row which is going to be updated/or not an
mutating error could not happen in this context, right? In general I wonder if the trigger above could be used or if it is better to have such logic somewhere else?

Thanks much in advance for you help.

Best regards,
Dirk. Received on Wed Aug 27 2008 - 14:07:44 CDT