mirror of https://github.com/django/django.git
52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
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"""
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12. Relating a model to another model more than once
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In this example, a ``Person`` can have a ``mother`` and ``father`` -- both of
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which are other ``Person`` objects.
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Because a ``Person`` has multiple relationships to ``Person``, we need to
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distinguish the relationships. Set ``rel_name`` to tell Django what the
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relationship should be called, because ``Person`` has two relationships to the
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same model. Also, set ``related_name`` to designate what the reverse
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relationship is called.
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"""
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from django.core import meta
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class Person(meta.Model):
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fields = (
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meta.CharField('full_name', maxlength=20),
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meta.ForeignKey('self', null=True, rel_name='mother',
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related_name='mothers_child'),
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meta.ForeignKey('self', null=True, rel_name='father',
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related_name='fathers_child'),
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)
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def __repr__(self):
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return self.full_name
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API_TESTS = """
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# Create two Person objects -- the mom and dad in our family.
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>>> dad = persons.Person(id=None, full_name='John Smith Senior', mother_id=None, father_id=None)
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>>> dad.save()
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>>> mom = persons.Person(id=None, full_name='Jane Smith', mother_id=None, father_id=None)
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>>> mom.save()
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# Give mom and dad a kid.
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>>> kid = persons.Person(id=None, full_name='John Smith Junior', mother_id=mom.id, father_id=dad.id)
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>>> kid.save()
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>>> kid.get_mother()
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Jane Smith
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>>> kid.get_father()
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John Smith Senior
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>>> dad.get_fathers_child_list()
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[John Smith Junior]
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>>> mom.get_mothers_child_list()
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[John Smith Junior]
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>>> kid.get_mothers_child_list()
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[]
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>>> kid.get_fathers_child_list()
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[]
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"""
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