title: Circular dependency in Django ForeignKey?
body: <p>I have two models in Django:</p>
  
  <pre><code>A:
    b = ForeignKey("B")
  
  B:
    a = ForeignKey(A)
  </code></pre>
  
  <p>I want these ForeignKeys to be non-NULL.</p>
  
  <p>However, I cannot create the objects because they don't have a PrimaryKey until I save(). But I cannot save without having the other objects PrimaryKey.</p>
  
  <p>How can I create an A and B object that refer to each other?
  I don't want to permit NULL if possible.</p>