title: Select all fields where fieldone is not equal to null + Propel
body: <p>I have a question about using the propel ORM and creating a query. </p>
  
  <p>I have a table <strong>"locations"</strong> with fields:<br></p>
  
  <blockquote>
    <ul>
    <li>location <br></li>
    <li>sublocation<br></li>
    <li>postcode<br></li>
    <li>street<br></li>
    <li>number<br></li>
    </ul>
  </blockquote>
  
  <p>Now I want to select all the locations where the location field <strong>IS NOT</strong> equal to 'null'.<br>
  How can I do this? I've tried this but I get back all the results ...</p>
  
  <p>Tried query: <code>$locations = LocationQuery::create()-&gt;where('location' != null)-&gt;find();</code></p>