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Django Models: Ancestral Inheritance and Succession

I thought I would work a little on my game with Django, developing a large-scale business application for fun. I saw the need for a common ancestor approach to modeling inheritance and tried to implement it based on official documentation. However, I keep getting this very annoying message, which I'm not sure what to do.

  • Dj Version: Django 1.7
  • Py Version: Python 3.4.2

Message

$ python manage.py makemigrations

You are trying to add a non-nullable field 'businessentity_ptr' to business without a default; we can't do that (the database needs something to populate existing rows).

Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows)
 2) Quit, and let me add a default in models.py

Models.py

class BusinessEntity(models.Model):
    title = models.CharField(max_length=180)

    def __str__(self):
        return self.title


class Business(BusinessEntity):
    description = models.TextField(max_length=600)
    claimed = models.BooleanField(default=False)
    slug = models.SlugField()
    timestamp = models.DateTimeField(auto_now_add=True, auto_now=False)
    updated = models.DateTimeField(auto_now_add=False, auto_now=True)

    def __str__(self):
        return self.description

What I tried (which everyone will hate):

  • Database deletion and re-migration
  • setting default value for all fields
  • Setting all fields to null = True

, , . , -, Django Common Ancestors .

0
1

, .

class BusinessEntity(models.Model):
    title = models.CharField(max_length=180)

    class Meta:
        abstract = True

Django _ptr, . .

+5

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