Django: Two different child classes point to same parent class

Question

I have a model Person which stores all data about people. I also have a Client model which extends Person. I have another extending model OtherPe

Answer 1

You can't really do that with subclassing. When you subclass Person, you're implicitly telling Django that you'll be creating subclasses, not Person objects. It's a PITA to take a Person and transmogrify it into a OtherPerson later.

You probably want a OneToOneField instead. Both Client and OtherPerson should be subclasses of models.Model:

class Client(models.Model):
    person = models.OneToOneField(Person, related_name="client")
    # ...

class OtherPerson(models.Model):
    person = models.OneToOneField(Person, related_name="other_person")
    # ...

Then you can do things like:

pers = Person(...)
pers.save()
client = Client(person=pers, ...)
client.save()
other = OtherPerson(person=pers, ...)
other.save()

pers.other.termination_date = datetime.now()
pers.other.save()

See https://docs.djangoproject.com/en/dev/topics/db/examples/one_to_one/ for more.