title: django "only()" method seems not to work properly
body: <p>Models.py</p>
  
  <pre><code>class Post(models.Model):
      id = models.IntegerField(default=0)
      name = models.CharField(max_length=200, default='', blank=True)
      click = models.IntegerField(default=0)
      content = models.CharField(max_length=200, default='', blank=True)
  </code></pre>
  
  <p>Below, what I coded</p>
  
  <pre><code>post = Post.objects.filter(id=3).only('name')
  print(post.values())
  </code></pre>
  
  <p>Result what I expected</p>
  
  <pre><code>&lt;QuerySet [{'name': 'Micheal'}]&gt;
  </code></pre>
  
  <p>But the actual result was</p>
  
  <pre><code>&lt;QuerySet [{'id': 3, 'name': 'Micheal', 'click': 2, 'content': 'asdf'}]&gt;
  </code></pre>
  
  <p>How can I fix the problem?</p>