title: having the full field object instead of it's ID in django model
body: <p>with these two models TblPhoto</p>
  
  <pre><code>class TblPhoto(models.Model):
      #path = models.CharField(max_length=256)
      type = models.ForeignKey('TblPhotoTypes', models.DO_NOTHING, blank=True, null=True)
      path = models.ImageField(upload_to='images')
  
      def __str__(self):
          return str(self.id)
  
      class Meta:
          managed = False
          db_table = 'tbl_photo'
          verbose_name = "Photo"
          verbose_name_plural = "Photos"
  </code></pre>
  
  <p>and TblCustomer</p>
  
  <pre><code>class TblCustomer(models.Model):
      name = models.CharField(max_length=32)
      email = models.CharField(max_length=32)
      password = models.CharField(max_length=32)
      token = models.CharField(max_length=64, blank=True, null=True)
      firebase_token = models.CharField(max_length=64, blank=True, null=True)
      registration_date = models.IntegerField(blank=True, null=True)
      last_login_date = models.IntegerField(blank=True, null=True)
      about = models.TextField(max_length=128, blank=True, null=True)
      active = models.BooleanField(blank=True, null=True)
      photo = models.ForeignKey(TblPhoto, models.DO_NOTHING)
  
      def __str__(self):
          return str(self.id)+' : '+self.name
  
      class Meta:
          managed = False
          db_table = 'tbl_customer'
          verbose_name = "Customer"
          verbose_name_plural = "Customers"
  </code></pre>
  
  <p>the api response is...</p>
  
  <pre><code>{
      "response_status": {
          "code": 200,
          "internalMessage": "",
          "message": ""
      },
      "user": {
          "id": 1,
          "name": "deya",
          "email": "gmail@gmail.com",
          "password": "",
          "token": null,
          "firebase_token": null,
          "registration_date": null,
          "last_login_date": null,
          "about": "hello, i'm Deya !",
          "active": true,
          "photo_id": 4
      }
  }
  </code></pre>
  
  <p>notice the field photo_id, how can I alter the TblCustomer model to show the photo object instead of the photo id?</p>
  
  <blockquote>
    <p>Disclaimer : I can do this easily out of the model, but I want it to be in the
    model class.</p>
  </blockquote>
  
  <p>this is how I do it now... to get the additional <code>photo_url</code> key but I want to do it from the model....</p>
  
  <pre><code>class CustomerProfileView(BaseView):
      def post(self, request, format=None):
          requestBody = json.loads(request.body)
          id = requestBody["id"]
          try:
              user = TblCustomer.objects.values().get(id=id)
              photo = TblPhoto.objects.values().get(id=user["photo_id"])
              user["photo_url"] = request.scheme+"://"+request.get_host()+"/media/"+photo["path"]
              self.responseDict["user"] = user
          except Exception as e:
              return Helpers().statusCode(404,e)
          return JsonResponse(self.responseDict)
  </code></pre>