如何在Django中将用户从组添加到模型？

Question

I have a Company that has juniors and seniors. I would like to add users by adding groups instead of individually. Imagine I have Group 1, made of 3 seniors, instead of adding those 3 individually, I'd like to be able to just add Group 1, and have the 3 seniors automatically added to the list of seniors. I'm a little stuck in my current implementation:

class Company(django.model):
    juniors = m2m(User)
    seniors = m2m(User)

    junior_groups = m2m(Group)
    senior_groups = m2m(Group)

# currently, I use this signal to add users from a group when a group is added to company
def group_changed(sender, **kwargs):
    if kwargs['action'] != 'post_add': return None

    co = kwargs['instance']
    group_id = kwargs['pk_set'].pop()
    juniors = MyGroup.objects.get(pk=group_id).user_set.all()
    co.juniors = co.juniors.all() | juniors
    co.save()

m2m_changed.connect(...)

The main problem is this looks messy and I have to repeat it for seniors, and potentially other types of users as well.

Is there a more straightforward way to do what I'm trying to do?

Thanks in advance!

Answer 1

are you trying to optimize and avoid having the group object used in your queries ?

if you are ok with a small join query you could use this syntax to get the juniors in company with id = COMP_ID

this way you don't need to handle the users directly and copy them all the time

juniors = User.objects.filter(groups__company_id = COMP_ID , groups__type = Junior)

seniors = User.objects.filter(groups__company_id = COMP_ID , groups__type = Senior)

assuming that

• you add related_name "groups" to your m2m relation between groups and users
• your groups have type which you manage
• you called your foreign-key field 'company' on you Group model

this query can be added as a Property to the company Model , so it give the same programmatic peace of mind