title: Django both filtered and total number of a certain field
body: <p>I have such model and query </p>
  
  <pre><code>class Employer(Models.model)
      name = ...
  
  class JobTitle(Models.model)
      name = ...
      employer = models.ForeignKey(Employer)
  </code></pre>
  
  <p>and query is</p>
  
  <pre><code>Employer.objects.select_related('jobtitle')
                        .filter(jtt__activatedate__range=[startdate,enddate])
                        .annotate(jtt_count=Count('jobtitle'))
                        .order_by('-jtt_count')[:5]
  </code></pre>
  
  <p>As you see it returns 5 employer list which has maximum number of jobtitles which are related to that employer and whose activation date is in some certain range.</p>
  
  <p>However, I also want to get the total number of jobtitles of each employer in that query.
  Of course I may loop over each employer and make such query <code>JobTitle.objects.filter(employer = emp)</code> and taking length of that query but it is bad solution.</p>
  
  <p>How can I achive this in that query?
  Although it may not be possible to get both total number and filtered number of job titles, I may get the jobttiles of each emplyoer such that <code>len(emp.jobtitle)</code> however it also didn't work.</p>
  
  <p>Thanks</p>