title: ORACLE and TRIGGERS (inserted, updated, deleted)
body: <p>I would like to use a trigger on a table which will be fired every time a row is inserted, updated, or deleted.</p>
  
  <p>I wrote something like this:</p>
  
  <pre><code>CREATE or REPLACE TRIGGER test001
    AFTER INSERT OR DELETE OR UPDATE ON tabletest001
    REFERENCING OLD AS old_buffer NEW AS new_buffer 
    FOR EACH ROW WHEN (new_buffer.field1 = 'HBP00') 
  </code></pre>
  
  <p>and it works. 
  Since I would like to do the same things if the row is inserted, updated, or deleted, I would like to know what's happening in the trigger.
  I think I can manage to find if the row is inserted or updated (I can check the old_buffer with the new_buffer).
  How can I know if the row has been deleted?</p>