OnlineJudge/oj/db_router.py

class DBRouter(object):
    def db_for_read(self, model, **hints):
        if model._meta.app_label == "submission":
            return "submission"
        return "default"

    def db_for_write(self, model, **hints):
        if model._meta.app_label == "submission":
            return "submission"
        return "default"

    def allow_relation(self, obj1, obj2, **hints):
        return True

    def allow_migrate(self, db, app_label, model=None, **hints):
        if app_label == "submission":
            return db == app_label
        else:
            return db == "default"