Add user to group to specific database does not work

Using Django Using the ORM
1

Hai,
I am struggling to make the following code works for me.

user = User.objects.using(data[‘db_name’]).get(pk=1)
group = Group.objects.using(data[‘db_name’]).get(pk=2)
user.groups.add(group)

I can see that Django creates one record to auth_user_groups in the default database but not in the data[‘db_name’]) database. Interestingly, user and group objects are coming from data[‘db_name’] database.

Can anyone advise me how to add new record to data[‘db_name’] database successfully?

2

The groups in the expression user.groups.add(group) is a manager, similar to objects.

Try using using in that expression. (e.g., user.groups.using(...).add(group))

Actually, I’m surprised that the user.groups.add works when either user or group aren’t in the default database.

3

Hai,
Thanks.

Just to confirm the above code works but I have custom db route that unexpectedly creates related table records to default database and not the database of parent object. I ended up changing my db route’s write function to get the correct database name.

user.groups.add(group)

So when db_for_write function gets called I get database name from **hint which is the same database as user object and that is what I needed.

def db_for_write(self, model, **hints):

        if hints.get('instance') is not None:
          _instance = hints['instance']
          return _instance._state.db
        else:
          return get_current_db_name()


def get_current_db_name():
        return getattr(THREAD_LOCAL, "DB", None)