cmsmanage/doorcontrol/routers.py

class DoorControlRouter:
    app_label = "doorcontrol"
    db = "doors"

    def db_for_read(self, model, **hints):
        if model._meta.app_label == self.app_label:
            return self.db
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label == self.app_label:
            return self.db
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label == self.app_label:
            return db == self.db
        return None

    def allow_relation(self, obj1, obj2, **hints):
        if (
            obj1._meta.app_label == self.app_label
            or obj2._meta.app_label == self.app_label
        ):
            return True
        return None