title: Django-Rest-Framework updating a foreign key BY Id
body: <p>I am using django-rest-framework to build out the back end.  I have the list running fine, but (using the django-rest-framework admin screen) I cannot create an object by just using the Id fields of the foreign key objects.  I hope I have this configured incorrectly,  but I am open to writing some code if i have to :)  I am learning django/python from a .NET and Java background and may have become a touch spoiled by this new stack.</p>
  
  <p><strong>Edit: I am trying not to use two different Model classes- I shouldn't have to right?</strong></p>
  
  <p>Thanks in advance.</p>
  
  <p>From Chrome - the key bits of the request</p>
  
  <pre><code>Request URL:http://127.0.0.1:8000/rest/favorite_industries/ 
  Request Method:POST 
  _content_type:application/json
  _content:{
      "user_id": 804    ,"industry_id": 20 }
  </code></pre>
  
  <p>The response</p>
  
  <pre><code>HTTP 400 BAD REQUEST
  Vary: Accept
  Content-Type: text/html; charset=utf-8
  Allow: GET, POST, HEAD, OPTIONS
  
  {
      "user": [
          "This field is required."
      ]
  }
  </code></pre>
  
  <p>Ugh.  Here are the key classes from django:</p>
  
  <pre><code>class FavoriteIndustry(models.Model):
      id = models.AutoField(primary_key=True)
      user = models.ForeignKey(User, related_name='favorite_industries')
      industry = models.ForeignKey(Industry)
  
      class Meta:
          db_table = 'favorites_mas_industry'
  
  class FavoriteIndustrySerializer(WithPkMixin, serializers.HyperlinkedModelSerializer):
      class Meta:
          model = myModels.FavoriteIndustry
          fields = (
              'id'
              , 'user'
              , 'industry'
          )
  </code></pre>
  
  <p><strong>Edit Adding the viewset:</strong></p>
  
  <pre><code>class FavoriteIndustriesViewSet(viewsets.ModelViewSet):
      #mixins.CreateModelMixin, viewsets.GenericViewSet):
      paginate_by = 1
      queryset = myModels\
          .FavoriteIndustry\
          .objects\
          .select_related()
      print 'SQL::FavoriteIndustriesViewSet: ' + str(queryset.query)
      serializer_class = mySerializers.FavoriteIndustrySerializer
  </code></pre>
  
  <p>The get/list functionality generates decent JSON:</p>
  
  <blockquote>
    <p>{"count": 2, "next":
    "<a href="http://blah.com/rest/favorite_industries/?page=2&amp;format=json">http://blah.com/rest/favorite_industries/?page=2&amp;format=json</a>",
    "previous": null, "results": [{"id": 1, "user":
    "<a href="http://blah.com/rest/users/804/">http://blah.com/rest/users/804/</a>", "industry": {"industry_id":
    2, "industry_name": "Consumer Discretionary", "parent_industry_name":
    "Consumer Discretionary", "category_name": "Industries"}}]}</p>
  </blockquote>