title: Oracle - Custom Sort
body: <p>I have a dataset</p>
  <pre><code>**ITEM              ITEM_PARENT** 
  100096635          (null)
  100201836          (null)
  1234560690640      100096635
  1234561457648      100201836
  </code></pre>
  <p>I want to sort as:</p>
  <pre><code>**ITEM              ITEM_PARENT** 
  100096635          (null)
  1234560690640      100096635
  100201836          (null)
  1234561457648      100201836
  </code></pre>
  <p>How can I do that?</p>