title: Any way to update a ManyToMany field via a queryset?
body: <p>Suppose I have an object:</p>
  
  <pre><code>survey = Survey.objects.all().first()
  </code></pre>
  
  <p>and I want to create a relationship between it and a group of objects:</p>
  
  <pre><code>respondents = Respondent.objects.all()
  
  for r in respondents:
      r.eligible_for.add(survey)
  </code></pre>
  
  <p>where <code>eligible_for</code> is an M2M field in the <code>Respondent</code> model.</p>
  
  <p>Is there any way to do it in one pass, or do I need to loop over the queryset?</p>
  
  <p><strong>models.py</strong></p>
  
  <pre><code>class Questionnaire(models.Model):
      label = models.CharField(max_length=48)
      organization = models.ForeignKey('Home.Organization', on_delete=models.PROTECT, null=True)
  
  class Respondent(models.Model):
      user = models.OneToOneField('Home.ListenUser', on_delete=models.CASCADE)
      organization = models.ForeignKey('Home.Organization', on_delete=models.PROTECT)
      eligible_for = models.ManyToManyField('Questionnaire', related_name='eligible_users', blank=True)
  </code></pre>