title: How to see if a value or object is in a QuerySet field
body: <p>How would I see if a value is in a QuerySet? </p>
  
  <p>For example, if I have the following model: </p>
  
  <pre><code>class UserProfile(models.Model):
      user = models.ForeignKey(User, unique=True)
      first_name = models.CharField(max_length=50)
  </code></pre>
  
  <p>How would I find out if the first_name 'David' is contained in a QuerySet? A way to do the following: </p>
  
  <pre><code>ld = UserProfile.objects.filter(...).values('first_name')
      &gt;&gt;&gt; for object in ld:
      ...     if object['first_name'] =='David':
      ...             print True
  </code></pre>
  
  <p>Or if a particular user object is instead? Something like <code>'David' in QuerySet['first_name']</code> ? Thank you.</p>