title: Django Rest Serializer returns empty
body: <p>I'm following this tutorial (<a href="http://www.django-rest-framework.org/api-guide/serializers/#modelserializer" rel="nofollow noreferrer">Django Rest Framework</a>) and I'm facing a problem when I try to use serializers. It returns a empty result, instead the 49086 records that it should to return. My query it's ok because when I try to show the data without serializers it's shows these data. Please, what I'm doing wrong?</p>
  
  <p><strong>models.py</strong></p>
  
  <pre><code># coding=utf-8
  
  from __future__ import unicode_literals
  from django.db import models
  
  
  class Workers(models.Model):
      chapa = models.IntegerField(primary_key=True)
      emp_cod = models.IntegerField(primary_key=False)
      class Meta:
          managed = False
          db_table = 'WORKERS'
  </code></pre>
  
  <p><strong>serializers.py</strong></p>
  
  <pre><code>from rest_framework import serializers
  from .models import Workers
  
  
  class WorkersSerializer(serializers.ModelSerializer):
      class Meta:
          model = Workers
          fields = '__all__'
  </code></pre>
  
  <p><strong>views.py</strong></p>
  
  <pre><code>...
  @api_view(['GET'])
  @permission_classes((permissions.AllowAny,))
  def get_all_workers(request):
      data = Workers.objects.using('rh').all().order_by('emp_cod')
      print(data.count()) # Returns 49086
      serializer = WorkersSerializer(data)
      print(serializer.data) # Returns {}
      json = JSONRenderer().render(serializer.data)
      return Response(json) # Returns Django Rest standard page with "{}" data
  </code></pre>