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"""
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(max_length=20)
mother = models.ForeignKey('self', null=True, related_name='mothers_child_set')
father = models.ForeignKey('self', null=True, related_name='fathers_child_set')
def __unicode__(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()
[]
"""}
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