title: DATE_ADD() on select() with codeigniter
body: <p>I'm wondering how I could use mysql <code>DATE_ADD()</code> in codeigniter <code>SELECT</code> . </p>
  
  <p>EDIT: ... <code>DATE_ADD()</code> and basically any other MySQL Function within <code>SELECT</code> .</p>
  
  <p>This is what I have. Also tried putting <code>FALSE</code> as second parameter.</p>
  
  <pre><code>$this-&gt;db-&gt;select(" DATE_ADD( purchased_on , INTERVAL 1 YEAR) AS wrty_end");
  </code></pre>
  
  <p>The result is that it reads <code>INTERVAL</code> as a field. It works fine when I try to run this in phpmyadmin without the backticks enclosing <code>INTERVAL</code>.</p>
  
  <pre><code>DATE_ADD( purchased_on, `INTERVAL` 1 YEAR) AS wrty_end
  </code></pre>