title: SQLite3 trigger does not work
body: <p>The trigger defined below does not work in sqlite3.    </p>
  
  <pre><code>CREATE TRIGGER 'delete_expired' BEFORE INSERT ON 'visitor' BEGIN DELETE FROM visitor WHERE 'create_at' &lt;= date('now', '-6 day'); END
  </code></pre>
  
  <p>But, this does... Something might be wrong with the conditions. Can anybody point me out? Thanks in advance</p>
  
  <pre><code>CREATE TRIGGER 'delete_expired' BEFORE INSERT ON 'visitor' BEGIN DELETE FROM visitor; END
  </code></pre>