mirror of
https://github.com/django/django.git
synced 2024-12-27 03:25:58 +00:00
d4a0b27838
* Renamed the __unicode__ methods * Applied the python_2_unicode_compatible decorator * Removed the StrAndUnicode mix-in that is superseded by python_2_unicode_compatible * Kept the __unicode__ methods in classes that specifically test it under Python 2
33 lines
994 B
Python
33 lines
994 B
Python
"""
|
|
11. Relating an object to itself, many-to-one
|
|
|
|
To define a many-to-one relationship between a model and itself, use
|
|
``ForeignKey('self')``.
|
|
|
|
In this example, a ``Category`` is related to itself. That is, each
|
|
``Category`` has a parent ``Category``.
|
|
|
|
Set ``related_name`` to designate what the reverse relationship is called.
|
|
"""
|
|
|
|
from django.db import models
|
|
from django.utils.encoding import python_2_unicode_compatible
|
|
|
|
|
|
@python_2_unicode_compatible
|
|
class Category(models.Model):
|
|
name = models.CharField(max_length=20)
|
|
parent = models.ForeignKey('self', blank=True, null=True, related_name='child_set')
|
|
|
|
def __str__(self):
|
|
return self.name
|
|
|
|
@python_2_unicode_compatible
|
|
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 __str__(self):
|
|
return self.full_name
|