我希望保护一些行不被删除,而且我更喜欢使用触发器而不是应用程序的逻辑来实现。我正在使用MySQL数据库。
我的想法是这样的:
DELIMITER $$
DROP TRIGGER `preserve_permissions`$$
USE `systemzarzadzaniareporterami`$$
CREATE TRIGGER `preserve_permissions`
AFTER DELETE ON `permissions`
FOR EACH ROW
BEGIN
IF old.`userLevel` = 0 AND old.`permissionCode` = 164 THEN
INSERT INTO `permissions` SET `userLevel`=0, `permissionCode`=164;
END IF;
END$$
DELIMITER ;
但是当我使用delete时,它会给我一个错误:
DELETE FROM `systemzarzadzaniareporterami`.`permissions`
WHERE `userLevel` = 0 AND `permissionCode` = 164;
Error Code: 1442. Can't update table 'permissions' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
有没有其他方法可以做这件事?