mirror of
https://github.com/django/django.git
synced 2024-11-20 00:14:08 +00:00
0fec0a5d70
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10550 bcc190cf-cafb-0310-a4f2-bffc1f526a37
84 lines
2.4 KiB
Python
84 lines
2.4 KiB
Python
from django.db import models
|
|
|
|
# No related name is needed here, since symmetrical relations are not
|
|
# explicitly reversible.
|
|
class SelfRefer(models.Model):
|
|
name = models.CharField(max_length=10)
|
|
references = models.ManyToManyField('self')
|
|
related = models.ManyToManyField('self')
|
|
|
|
def __unicode__(self):
|
|
return self.name
|
|
|
|
class Tag(models.Model):
|
|
name = models.CharField(max_length=10)
|
|
|
|
def __unicode__(self):
|
|
return self.name
|
|
|
|
# A related_name is required on one of the ManyToManyField entries here because
|
|
# they are both addressable as reverse relations from Tag.
|
|
class Entry(models.Model):
|
|
name = models.CharField(max_length=10)
|
|
topics = models.ManyToManyField(Tag)
|
|
related = models.ManyToManyField(Tag, related_name="similar")
|
|
|
|
def __unicode__(self):
|
|
return self.name
|
|
|
|
# Two models both inheriting from a base model with a self-referential m2m field
|
|
class SelfReferChild(SelfRefer):
|
|
pass
|
|
|
|
class SelfReferChildSibling(SelfRefer):
|
|
pass
|
|
|
|
__test__ = {"regressions": """
|
|
# Multiple m2m references to the same model or a different model must be
|
|
# distinguished when accessing the relations through an instance attribute.
|
|
|
|
>>> s1 = SelfRefer.objects.create(name='s1')
|
|
>>> s2 = SelfRefer.objects.create(name='s2')
|
|
>>> s3 = SelfRefer.objects.create(name='s3')
|
|
>>> s1.references.add(s2)
|
|
>>> s1.related.add(s3)
|
|
|
|
>>> e1 = Entry.objects.create(name='e1')
|
|
>>> t1 = Tag.objects.create(name='t1')
|
|
>>> t2 = Tag.objects.create(name='t2')
|
|
>>> e1.topics.add(t1)
|
|
>>> e1.related.add(t2)
|
|
|
|
>>> s1.references.all()
|
|
[<SelfRefer: s2>]
|
|
>>> s1.related.all()
|
|
[<SelfRefer: s3>]
|
|
|
|
>>> e1.topics.all()
|
|
[<Tag: t1>]
|
|
>>> e1.related.all()
|
|
[<Tag: t2>]
|
|
|
|
# The secret internal related names for self-referential many-to-many fields
|
|
# shouldn't appear in the list when an error is made.
|
|
>>> SelfRefer.objects.filter(porcupine='fred')
|
|
Traceback (most recent call last):
|
|
...
|
|
FieldError: Cannot resolve keyword 'porcupine' into field. Choices are: id, name, references, related, selfreferchild, selfreferchildsibling
|
|
|
|
# Test to ensure that the relationship between two inherited models
|
|
# with a self-referential m2m field maintains symmetry
|
|
>>> sr_child = SelfReferChild(name="Hanna")
|
|
>>> sr_child.save()
|
|
|
|
>>> sr_sibling = SelfReferChildSibling(name="Beth")
|
|
>>> sr_sibling.save()
|
|
>>> sr_child.related.add(sr_sibling)
|
|
>>> sr_child.related.all()
|
|
[<SelfRefer: Beth>]
|
|
>>> sr_sibling.related.all()
|
|
[<SelfRefer: Hanna>]
|
|
|
|
"""
|
|
}
|