related_name argument not working as expected in Django model?
Question:
I recently got a ForeignKey clash in my Django model. I have the need to have two foreign keys (owner, assigned_to) ultimately pointing to the same model (a user).
From what I understand I need a related_name argument to solve that problem. So I did that:
assigned_to = models.ForeignKey(TaskUser, blank=True, null=True, related_name='user_assignment')
and
owner = models.ForeignKey(TaskUser, related_name="user_ownership"
But I’m still getting an error:
tasks.task: Accessor for field 'owner' clashes with related field 'TaskUser.user
_ownership'. Add a related_name argument to the definition for 'owner'.
tasks.task: Reverse query name for field 'owner' clashes with related field 'TaskUser.user_ownership'. Add a related_name argument to the definition for 'owner'.
Why am I still getting this error?
There is one catch, owner is in a super class (BaseWidget) and assigned_to is in a sub class (Task). Are there issues with using related_name in an inheritance relationship? Do I need to just override the inheritance of owner and redefine related_name in the sub class instead? I’d appreciate any help!
Answers:
If you are using related_name in abstract base class you need to use a ‘%(app_label)s’ and ‘%(class)s’ in it.
Its mentioned in django doc
If you have ForeignKey relationships in an abstract base class every class inheriting from it will have this relationship. As a result of this you must not ‘hardcode’ its related_name, because all sub classes will try to create the same accessor on the realted class (TaskUser in this case).
You should better do something like:
owner = models.ForeignKey(TaskUser, related_name="%(app_label)s_%(class)s_ownership")
See the django docs on this.
I recently got a ForeignKey clash in my Django model. I have the need to have two foreign keys (owner, assigned_to) ultimately pointing to the same model (a user).
From what I understand I need a related_name argument to solve that problem. So I did that:
assigned_to = models.ForeignKey(TaskUser, blank=True, null=True, related_name='user_assignment')
and
owner = models.ForeignKey(TaskUser, related_name="user_ownership"
But I’m still getting an error:
tasks.task: Accessor for field 'owner' clashes with related field 'TaskUser.user
_ownership'. Add a related_name argument to the definition for 'owner'.
tasks.task: Reverse query name for field 'owner' clashes with related field 'TaskUser.user_ownership'. Add a related_name argument to the definition for 'owner'.
Why am I still getting this error?
There is one catch, owner is in a super class (BaseWidget) and assigned_to is in a sub class (Task). Are there issues with using related_name in an inheritance relationship? Do I need to just override the inheritance of owner and redefine related_name in the sub class instead? I’d appreciate any help!
If you are using related_name in abstract base class you need to use a ‘%(app_label)s’ and ‘%(class)s’ in it.
Its mentioned in django doc
If you have ForeignKey relationships in an abstract base class every class inheriting from it will have this relationship. As a result of this you must not ‘hardcode’ its related_name, because all sub classes will try to create the same accessor on the realted class (TaskUser in this case).
You should better do something like:
owner = models.ForeignKey(TaskUser, related_name="%(app_label)s_%(class)s_ownership")
See the django docs on this.