title: django query to filter and distinct
body: <p>I have a table as follows:</p>
  
  <p>table_name : example</p>
  
  <pre><code>values
  1
  1
  2
  
  2
  3
  
  3
  </code></pre>
  
  <p>the value list contains the values as above. When i write a distinct query on the able table, i get 1 2 3 and a empty '' value.</p>
  
  <p>I want to get rid of the <code>null</code> value as it is posing some problems in my program.
  the query for that which i have written is:</p>
  
  <pre><code>example.objects.values_list('values',flat = True).distinct()
  </code></pre>
  
  <p>Is there a a way to filter out that empty value</p>