title: how to use concat function in this trigger
body: <p>i have this trigger below which inserts new values in the an emplog table,i want to make my trigger to insert in the description column the event that took place for example if i changed the last_name i want it to appear old.lastname was changed to new.last_name,if its the first-name or gender or dob or marital or ssn that were updated it should do the same,im a newbie how can i achieve this lets say i want to use concat function??</p>
  
  <pre><code>CREATE TRIGGER emplog_update AFTER UPDATE ON emp 
  FOR EACH ROW 
  INSERT INTO emplog VALUES 
  (NEW.id,NEW.lastname,NEW.firstname,NEW.gender,NEW.dob,NEW.marital,NEW.SSN,'U',NULL,USER(),('this is where the description will go')); 
  </code></pre>