title: MySQL Trigger: IF ELSE error
body: <p>Trying to execute first ever trigger which should insert value of one table to another only if   the data is new. Below is my code:</p>
  
  <pre><code>BEGIN
      DECLARE email VARCHAR(30);
     INSERT INTO data_audit SET data_audit_id = OLD.id;
     IF (NEW.email = OLD.email) THEN
      email = NULL;
     ELSE
      email = OLD.email;
     END IF;
     UPDATE corporate_audit SET email = email WHERE corporate_audit_id = last_insert_id();
  END
  </code></pre>
  
  <p>I am getting following error:</p>
  
  <p><strong>You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '= NULL;
     ELSE
      email = OLD.email;
     END IF;
     UPDATE corporate_audit SET ' at line 5</strong></p>
  
  <p>And when I execute code without any IF-THEN block and store OLD.email then it just insert new ID in audit table but does not update field.
  Please guide me</p>