Im having trouble with a model classs which has a onetoone relation with the User model, this the conflictive part:
class UserInteraction(models.Model):
user = models.OneToOneField(User, related_name="interactions", on_delete=models.CASCADE)
users_follows = models.ManyToManyField('self', through='UserFollow', blank=True, symmetrical=False, related_name='user_follows')
users_likes = models.ManyToManyField('self', through='UserLike', blank=True, symmetrical=False, related_name='user_likes')
When I try to get the follows/likes by doing user.interactions.user_follows
or user.interactions.user_likes
I get the following error:
In [18]: u = User.objects.get(id=1)
In [19]: u.interactions.users_likes.all()
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
Input In [19], in <module>
----> 1 u.interactions.users_likes.all()
File ~\...\django\db\models\fields\related_descriptors.py:536, in ReverseManyToOneDescriptor.__get__(self, instance, cls)
533 if instance is None:
534 return self
--> 536 return self.related_manager_cls(instance)
File ~\...\django\db\models\fields\related_descriptors.py:826, in create_forward_many_to_many_manager.<locals>.ManyRelatedManager.__init__(self, instance)
824 self.prefetch_cache_name = rel.field.name
825 self.source_field_name = rel.field.m2m_field_name()
--> 826 self.target_field_name = rel.field.m2m_reverse_field_name()
827 self.symmetrical = rel.symmetrical
828 else:
File ~\...\django\db\models\fields\related.py:1598, in ManyToManyField._get_m2m_reverse_attr(self, related, attr)
1596 setattr(self, cache_attr, getattr(f, attr))
1597 break
-> 1598 return getattr(self, cache_attr)
AttributeError: 'ManyToManyField' object has no attribute '_m2m_reverse_name_cache'
Here is the follower and like models used for through in the fk:
class UserFollow(TimeStampBase):
follower = models.ForeignKey(User, on_delete=models.CASCADE, related_name='follower')
followed = models.ForeignKey(User, on_delete=models.CASCADE, related_name='followed')
class Meta:
constraints = [
models.UniqueConstraint(
name="%(app_label)s_%(class)s_unique_relationships",
fields=["followed", "follower"],
),
models.CheckConstraint(
name="%(app_label)s_%(class)s_prevent_self_follow",
check=~models.Q(follower=models.F("followed")),
),
]
def __str__(self):
return f'{self.follower} follows {self.followed}'
class UserLike(TimeStampBase):
liker = models.ForeignKey(User, on_delete=models.CASCADE, related_name='liker')
liked = models.ForeignKey(User, on_delete=models.CASCADE, related_name='liked')
class Meta:
constraints = [
models.UniqueConstraint(
name="%(app_label)s_%(class)s_unique_relationships",
fields=["liked", "liker"],
),
models.CheckConstraint(
name="%(app_label)s_%(class)s_prevent_self_follow",
check=~models.Q(liker=models.F("liked")),
),
]
def __str__(self):
return f'{self.liker} likes {self.liked}'
In the admin everything works fine, what im doing wrong?
CodePudding user response:
The ForeignKey fields in through models need to reference the model that contains the ManyToManyField and not the model in the OneToOneField - UserInteraction
and not User
class UserFollow(TimeStampBase):
follower = models.ForeignKey(UserInteraction, on_delete=models.CASCADE, related_name='follower')
followed = models.ForeignKey(UserInteraction, on_delete=models.CASCADE, related_name='followed')
...
class UserLike(TimeStampBase):
liker = models.ForeignKey(UserInteraction, on_delete=models.CASCADE, related_name='liker')
liked = models.ForeignKey(UserInteraction, on_delete=models.CASCADE, related_name='liked')
...