title: how to include null results in Django ORM queries
body: <p>I am using Django ORM system. I have model of students where each student has his/her prefered state of work. Like few students wanna work in "Mahrashtra' State and others wanna work in some other state.</p>
  
  <p>Let's suppose I wanna search for those students who have prefered working state as 'California'. I do following query</p>
  
  <pre><code>result= Students.object.filter(prefered_state='California')
  </code></pre>
  
  <p>and of course I get desired result but I wanna include even those students in results who haven't yet entered their preferred state. Means students with state as <strong>Null</strong> or <strong>''</strong>. So isn't there any way to specify to include Null results for criteria other than using <strong>OR</strong> statement. As I have many more criteria for many other fields and I don't wanna include OR xyz is null for every field</p>