mysql - 如何使用 where 子句进行 UPSERT

Question

我上网寻找并回答这个问题，但找不到答案。

我想在更新或插入之前检查四列。我无法使用 INSERT...ON DUPLICATE KEY UPDATE 因为它不允许使用 where 子句。所以我尝试使用我创建的以下语句。

"SELECT COUNT(id) INTO @count FROM room_prices WHERE (hotel_di = $hotel_id AND room_id = $room_id AND period_id = $periodId AND meal_plan_id = $mealPlanId) "
                . "IF @count > 0 THEN "
                . "UPDATE room_prices SET price = $price WHERE (hotel_di = $hotel_id AND room_id = $room_id AND period_id = $periodId AND meal_plan_id = $mealPlanId) "
                . "ELSE "
                . "INSERT INTO room_prices (hotel_id, room_id, period_id, meal_plan_id, price) VALUES ($hotel_id, $room_id, $periodId, $mealPlanId, $price) "
                . "END IF"

但是这个也不起作用。它给出了这个错误。

您提交的查询无效。

有什么办法可以做到这一点吗？

Answer 1

从 hotel_id、room_id、period_id、meal_plan_id 上的唯一索引开始:

CREATE UNIQUE INDEX idx_room_prices_4 on room_prices(hotel_id, room_id, period_id, meal_plan_id)

然后您可以使用重复 key 更新:

INSERT INTO room_prices(hotel_id, room_id, period_id, meal_plan_id, price) 
    SELECT $hotel_id, $room_id, $periodId, $mealPlanId, $price
    ON DUPLICATE KEY UPDATE price = $price;