title: ORA-04088: error during execution of trigger - additional errors
body: <p>I have a blank table for which I've set up a trigger:</p>
  
  <pre><code>CREATE OR REPLACE TRIGGER   authors_bir
  BEFORE INSERT ON authors
  FOR EACH ROW
  
  begin
    if upper(:new.name) = 'TEST' then
      raise_application_error(-20001, 'Sorry, that value is not allowed.');
    end if;
  end;
  </code></pre>
  
  <p>After executing:</p>
  
  <pre><code>insert into AUTHORS
      VALUES (1, 'test', '1-Jan-1989', 'M');
  </code></pre>
  
  <p>Why am I getting ORA-06512 and ORA-04088 error messages in addition to the expected ORA-20001 error prompt?</p>
  
  <p><strong>ErrorMessage</strong></p>
  
  <pre><code>Error starting at line : 5 in command -
  insert into AUTHORS
      VALUES (1, 'test', '1-Jan-1989', 'M')
  Error report -
  ORA-20001: Sorry, that value is not allowed.
  ORA-06512: at "RPS.AUTHORS_BIR", line 3
  ORA-04088: error during execution of trigger 'RPS.AUTHORS_BIR'
  </code></pre>