#1442 - 无法更新存储 function/trigger 中的 table '*'，因为它已被调用此存储 function/trigger 的语句使用

Question

我真的很不擅长 SQL，但我正在努力使我的数据库尽可能简单和简约。不复制值，而是使用引用和 ID。

现在插入查询后出现错误

1442 - Can't update table 'signed' in stored function/trigger because it is already used by statement which invoked this stored function/trigger

禁用触发器时可以插入查询。但是我的查询只是从 table 'users' 读取，所以不应该有冲突。我阅读了一些关于死锁的内容——查询在使用它或类似的东西时正在锁定 table，因此触发器无法更新行？想法我怎样才能做到这一点？

我简化了我的查询，所以只有重要的东西在那里。

查询：

INSERT INTO signed (time_of_start, player)
    SELECT time_of_game_id, users.user_id 
    FROM time_of_game, users
    WHERE time_of_game.time_of_start = "2017-02-01 12:00:00"
      AND users.steamid = "1234567890123456";

触发器：

CREATE TRIGGER `payment_for_joining` 
AFTER INSERT ON `signed`
FOR EACH ROW 
    UPDATE users  
    SET users.credit = users.credit-1
    WHERE users.user_id = NEW.player

Answer 1

它不允许您更新 table，因为它已经被调用此触发器的 INSERT INTO.. SELECT 查询读取。

另一种方法是禁用触发器并单独更新用户 table，例如：

INSERT INTO signed (time_of_start, player)
SELECT time_of_game_id, users.user_id FROM time_of_game, users
WHERE time_of_game.time_of_start="2017-02-01 12:00:00"
AND users.steamid="1234567890123456";

UPDATE users join time_of_game SET users.credit = users.credit-1
where time_of_game.time_of_start="2017-02-01 12:00:00"
AND users.steamid="1234567890123456";

如果有任何列链接这两个 table，您可以使用 ON 子句添加连接列。

#1442 - 无法更新存储 function/trigger 中的 table '*'，因为它已被调用此存储 function/trigger 的语句使用

#1442 - Can't update table '*' in stored function/trigger because it is already used by statement which invoked this stored function/trigger

mysql

triggers

mysql-error-1442