"""

12. Relating a model to another model more than once

In this example, a ``Person`` can have a ``mother`` and ``father`` -- both of

which are other ``Person`` objects.

Set ``related_name`` to designate what the reverse relationship is called.

"""

from django.db import models

class Person(models.Model):

    full_name = models.CharField(maxlength=20)

    mother = models.ForeignKey('self', null=True, related_name='mothers_child_set')

    father = models.ForeignKey('self', null=True, related_name='fathers_child_set')

    def __str__(self):

        return self.full_name

__test__ = {'API_TESTS':"""

# Create two Person objects -- the mom and dad in our family.

>>> dad = Person(full_name='John Smith Senior', mother=None, father=None)

>>> dad.save()

>>> mom = Person(full_name='Jane Smith', mother=None, father=None)

>>> mom.save()

# Give mom and dad a kid.

>>> kid = Person(full_name='John Smith Junior', mother=mom, father=dad)

>>> kid.save()

>>> kid.mother

<Person: Jane Smith>

>>> kid.father

<Person: John Smith Senior>

>>> dad.fathers_child_set.all()

[<Person: John Smith Junior>]

>>> mom.mothers_child_set.all()

[<Person: John Smith Junior>]

>>> kid.mothers_child_set.all()

[]

>>> kid.fathers_child_set.all()

[]

"""}