title: Querying models in django (two levels deep)
body: <p>If I have the following tables</p>
  
  <pre><code>class Town(models.Model):
      created = models.DateTimeField()
  
  class Street(models.Model):
      town = models.ForeignKey(Town)
      created = models.DateTimeField()
  
  class House(models.Model):
      street = models.ForeignKey(Street)
      created = models.DateTimeField()
  </code></pre>
  
  <p>How do I get all the <code>House</code>s in a <code>Town</code> if I have the name/id of the town?</p>