title: retrieving same column twice from a table
body: <p>I have a table named "address", which has:</p>
  
  <ul>
  <li>id</li>
  <li>title </li>
  <li>parent_id </li>
  </ul>
  
  <p>...fields. </p>
  
  <p>In the title column, the name of regions and districts are inserted. The regions have parent_id value of zero, and parent_id of the districts are id of the regions. </p>
  
  <p>I want a query which display regions in one column and it's respective districts in another column. </p>