title: How to get objects in a django joined table
body: <p>I have two apps each has one model:</p>
  
  <p><strong>company</strong> app models.py</p>
  
  <pre><code>class Company(models.Model):
     name = models.CharField()
     address = models.CharField()
  </code></pre>
  
  <p><strong>client</strong> app models.py    </p>
  
  <pre><code>class Client(models.Model):
      company = models.ForeignKey(Company)
      name = models.CharField()
  </code></pre>
  
  <p>I have a listview of my company:</p>
  
  <pre><code>class CompanyListView(ListView):
      model = Company
      form_class = CompanyForm
  
      def get_context_data(self, **kwargs):
          context = super(CompanyListView, self).get_context_data(**kwargs)
          context[client_list] = ???
  
      return context
  </code></pre>
  
  <p>My problem is how can I pass to <code>context[client_list]</code> client list count related to a specific company? </p>