Django many-to-many relationship to self with extra data, how do I select from a certain direction?
- by Jake
I have some hierarchical data where each Set can have many members and can belong to more than one Set(group)
Here are the models:
class Set(models.Model):
...
groups = models.ManyToManyField('self', through='Membership', symmetrical=False)
members = models.ManyToManyField('self', through='Membership', symmetrical=False)
class Membership(models.Model):
group = models.ForeignKey( Set, related_name='Members' )
member = models.ForeignKey( Set, related_name='Groups' )
order = models.IntegerField( default=-1 )
I want to know how to get all the members or all the groups for a Set instance.
I think I can do it as follows, but it's not very logical, can anyone tell me what's going on and how I should be doing it?
# This gives me a set of Sets
# Which seems to be the groups this Set belongs to
set_instance.set_set.all()
# These give me a set of Memberships, not Sets
set_instance.Members.all()
set_instance.Groups.all()
# These they both return a set of Sets
# which seem to be the members of this one
set_instance.members.all()
set_instance.groups.all()
