title: Django OneToOneField Structure
body: <p>I have been researching and looking through all the docs but I am still a bit confused, I think maybe because there are multiple ways to use the OnToOneField.</p>
  <p>I have 4 models, Pregame, Ingame, Postgame and Game. And I want 'Game' to contain the other three models.</p>
  <p>As of right now it looks like this...</p>
  <pre class="lang-py prettyprint-override"><code>    class Pregame(models.Model):
          game_id = models.CharField(max_length=10)
          other fields...
  
          def __str__(self):
              return str(self.game_id)
  
      class Ingame(models.Model):
          game_id = models.CharField(max_length=10)
          other fields...
  
          def __str__(self):
              return str(self.game_id)
  
      class Postgame(models.Model):
          game_id = models.CharField(max_length=10)
          other fields...
  
          def __str__(self):
              return str(self.game_id)
  
      class Game(models.Model):
          game_id = models.CharField(max_length=10)
          pregame = models.OneToOneField(
              Pregame, on_delete=models.CASCADE, null=True)
          ingame = models.OneToOneField(
              Ingame, on_delete=models.CASCADE, null=True)
          postgame = models.OneToOneField(
              Postgame, on_delete=models.CASCADE, null=True)
  
          def __str__(self):
              return str(self.game_id)
  </code></pre>
  <p>I am using OnToOne because each Game will only have one Pregame, Ingame and Postgame and the other three models will only belong to one Game.</p>
  <p>I have a couple questions I am confused about.</p>
  <p>Will I be able to have a Game object if one of the other model objects doesn't exist yet? Like if there is a Pregame but no Ingame or Postgame, will Game still exist with just Pregame inside of it? I seen a couple videos where they did a default='{}', is that what I should be doing?</p>
  <p>Each model has game_id and that is how I am connecting them all together into the'Game' object. Is there a OneToOneField option like game_id=game_id so the 'Game' model will automatically link all the models together or would I still have to do that separate?</p>
  <p>Thank you for your help and knowledge.</p>