title: Updating value via trigger AFTER UPDATE Oracle 11g
body: <p>I'm developing a small library database and I don't want to allow someone to update someone's ID. But I need to use AFTER UPDATE and FOR EACH STATEMENT (which I'm told is Oracle's default). So, basically, if someone updates the customer info and alter his/her ID or mistypes it, the trigger will automatically update it again to the old value. The problem is that Oracle won't let me use :NEW and :OLD when using FOR EACH STATEMENT. Are there any workarounds to this issue? </p>
  
  <pre><code>CREATE OR REPLACE TRIGGER alter_id_trigger
  AFTER UPDATE ON CUSTOMER
  BEGIN
     UPDATE CUSTOMER SET ID = :OLD.ID
     WHERE ID = :NEW.ID;
  END;
  </code></pre>
  
  <p>Thank you!</p>