Trigger Question

I want to create a trigger that will scan for several columns and if they are updated, write the old and new values to an audit table. I am trying a trigger AFTER UPDATE FOR EACH ROW that goes something like this:

    if :old.name <> :new.name then

       // procedure that adds user ID, sysdate and checks for INSERT vs. UPDATE
        record_change( :old.empid, "NAME", :old.name, :new.name);    end if;
    // repeated several times for various other fields

This appears to work sporadically, but not consistently, for example, if the new value is a null string nothing happens. If several columns are updated at once, not all seem to get audited.

Is there something I'm missing here? (Obviously!) Do I need a separate trigger for each column I want to audit? Received on Tue Dec 30 1997 - 00:00:00 CET