def get_last_tid(self):
        try:
            spec = {'tid': {'$gt': 0}}
            sort = [('tid', -1)]
            row = self.db.docs.find_one(spec, sort=sort)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return row['tid']
        return 0
def activate(self):
        """
        Syntax sugar that helps at django shell with fast tenant changing

        Usage:
            Tenant.objects.get(schema_name='test').activate()
        """
        connection = connections[get_tenant_database_alias()]
        connection.set_tenant(self)