title: Create JSON fixture for django models
body: <p>I have defined model as below:</p>
  
  <p>model.py</p>
  
  <pre><code>class User(models.Model):
      user_id = models.IntegerField()
      user_name = models.CharField(max_length=40)
      email = models.EmailField()
      city = models.CharField(max_length=40)
      class Meta:
          ordering = ['user_id']
          verbose_name = 'User MetaData'
          verbose_name_plural = 'Users MetaData'
      def __unicode__(self):
          return str(self.user_id)
  
  class VideoData(models.Model):
      video = models.CharField(max_length=40)
      time  = models.IntegerField()
      user = models.ForeignKey(User)
      class Meta:
          verbose_name = 'User_Video MetaData'
          verbose_name_plural = 'Users_Video MetaData'
  </code></pre>
  
  <p>Now I want to update models with "loaddata" command from JSON file. I have a JSON file in the format below:</p>
  
  <pre><code>{  
    "fields":{  
       "user id":12026,
       "user name":"Paul Graham",
       "email":"pgraham0@sun.com",
       "city":"China",
       "VIdeoData":[  
          {  
             "video":"Livetube",
             "time":0
          },
          {  
             "video":"Leexo",
             "time":22
          }
       ]
    },
    "pk":1,
    "model":"graph.user"
  },
  </code></pre>
  
  <p>when I used "manage.py loaddata" command i got </p>
  
  <pre><code>error : "User has no field named u'VideoData'"
  </code></pre>
  
  <p>How can I update the fields?</p>