mongoDB에서의 join(aggregate)

  @staticmethod
    def aggregate(collection, query):
        return DB.DATABASE[collection].aggregate(query)



def listing():
    user_id = ECTOKEN.get_user_id(object)
    event_category_receive = request.args.get("event_category_give")
    if event_category_receive == "":
        events = DB.list('event', {}, {'_id': False})
        cafes = DB.list('cafe', {}, {'_id': False})
    else:
        events = DB.aggregate('cafe',
                     {'$lookup': {'from': "event", 'localField': "idx", 'foreignField': "idx", 'as': "cafes"}},
                     {'$unwind': 'cafes'},
                     {'$project': {'idx': 1, 'cafe_name': 1, 'cafe_short_info': 1, 'event_category': '$cafes.event_category'}})
        cafes = DB.list('events', {'event_category': event_category_receive}, {'_id': False})

    for cafe in cafes:
        cafe_idx = str(cafe['idx'])
        cafe["count_heart"] = DB.count_documents('heart', {"cafe_idx": cafe_idx, "type": "heart"})
        cafe["heart_by_me"] = bool(DB.find_one('heart', {"cafe_idx": cafe_idx, "type": "heart", "user_id": user_id}, {'_id': False}))
        cafe["bookmark_by_me"] = bool(DB.find_one('heart', {"cafe_idx": cafe_idx, "type": "bookmark", "user_id": user_id}, {'_id': False}))
    return jsonify({"result": "success", 'cafes': cafes, 'events': events, 'event_category': event_category_receive})

lookup으로 조인
파이썬으로 mongoDB 제어하기