title: Django model inheritance, filtering models
body: <p>Given the following models:(don't mind the TextFields there're just for illustration)</p>
  
  <pre><code>class Base(models.Model):
     field1 = models.TextField()
  
     class Meta:
        abstract=True
  
  class Child1(Base):
     child1_field = models.TextField()
  
  class Child2(Base):
     child2_field = models.TextField()
  
  
  class Content(models.Model):
      aso_items = models.ManyToManyField('Base')
  </code></pre>
  
  <p>According to these definitions a Content object can be associated with more than one Base object, eg. an interview(=Content object) can be linked with a musician(=Child1 object), a filmdirector(=Child2), etc.</p>
  
  <p>Now, for my question:
  Is it possible to filter Content objects according to which model the aso_items field points to?
  An example : Say I would like a Queryset containing all the Content objects that are associated with a specific object of Child1(eg. all the interviews associated with the musician Bob Dylan), how can I achieve this? </p>
  
  <p>Further, what if I'd want a QuerySet containing all the Content objects that are associated with Child1 objects?(eg. all the interviews that associated with musicians)
  How does this change the filtering?</p>
  
  <p>Thanks in advance
  ps: I'm experiencing some problems with white space in the preview, forgive me</p>