title: Value IS NOT NULL in codeigniter
body: <p>I am trying to create the following statement:</p>
  
  <pre><code>select * from donors where field is NOT NULL;
  </code></pre>
  
  <p>With codeigniter, my code looks like this:</p>
  
  <pre><code>$where = ['field' =&gt; NULL];
  $this-&gt;db-&gt;get_where('table', $where);
  </code></pre>