title: How to get missing data using Django model query?
body: <p>In Django, there is the <code>filter()</code> method to filter data. So I can pass an array of data and get the filtered results like this <code>model.objects.filter(id__in=id_array)</code>.</p>
  
  <p>Is there a way to get missing data using Django model query? 
  How to get a list of <code>id_array</code> elements which don't exist in the database?</p>