title: Howto merge 2 Django QuerySets in one and make a SELECT DISTINCT
body: models.py
  
  <pre><code>class SinglePoint(models.Model):
      attributes = models.TextField(blank=True)
      name = models.CharField(max_length=100)
      geom = models.PointField() #Kartenposition
      objects = models.GeoManager()
  
  class Connection(models.Model):
      name = models.CharField(max_length=100)
      #points = models.ManyToManyField(SinglePoint) #OLD
      p1 = models.ForeignKey(SinglePoint, related_name='p1_set') #NEW
      p2 = models.ForeignKey(SinglePoint, related_name='p2_set') #NEW
      obs = models.ManyToManyField(Observation, blank=True)
      conds = models.ManyToManyField(Condition, blank=True)
      objects = models.GeoManager()
  
  class Meta:
      order_with_respect_to = 'p1'
  </code></pre>
  
  <p>In my view.py:</p>
  
  <pre><code>...
  p1_points = SinglePoint.objects.filter(p1_set__vektordata__order__project__slug=slug)
  p2_points = SinglePoint.objects.filter(p2_set__vektordata__order__project__slug=slug)
  ...
  </code></pre>
  
  <p>Before I switched to ForeignKey, it worked with:</p>
  
  <pre><code>points = SinglePoint.objects.filter(connection__vektordata__order__project__slug=slug)
  </code></pre>
  
  <p>How to 'join' these two QuerySets to one QuerySet and make a distinct()?</p>
  
  <p>Thanks!</p>