mysql - 我怎样才能通过验证来触发删除

Question

我是论坛新手，我有以下问题，我想在删除租赁表位置后进入表电影并使列情况变得可用，但如果我有电影的代码在另一个寄存器的表位置中，我仍然将表膜的列状态保留为租用状态，我该怎么做？

这就是我所做的

TRIGGER `tguDelete` AFTER DELETE ON `locations` FOR EACH ROW UPDATE movies SET situation = 'available' WHERE code_location = OLD.code_location

我想发布 table 的图片，但我是论坛新手请帮助我!

我使用phpmyadmin，而且我是mysql新手

Answer 1

我认为您的触发器定义需要一些工作。例如 - 您想要声明“触发函数”，该函数应在位置上的DELETE操作之后执行> 表。您可以这样做:

DROP TRIGGER IF EXISTS `tguDelete`;
DELIMITER $$
CREATE TRIGGER `tguDelete` AFTER DELETE ON `locations` 
FOR EACH ROW 
-- condition for rows for which the trigger would fire WHEN (OLD.code_location <> 0)
-- DECLARE
   -- if you had things you wanted to declare
BEGIN
   -- here you do the updating of the movies table:
   UPDATE movies SET situation = 'available' WHERE code_location = OLD.code_location;
END;$$
DELIMITER ;

如果您不需要分隔符(即:PHPMyAdmin)，则跳过它们，例如

DROP TRIGGER IF EXISTS `tguDelete`;
CREATE TRIGGER `tguDelete` AFTER DELETE ON `locations` 
FOR EACH ROW 
-- condition for rows for which the trigger would fire WHEN (OLD.code_location <> 0)
-- DECLARE
   -- if you had things you wanted to declare
BEGIN
   -- here you do the updating of the movies table:
   UPDATE movies SET situation = 'available' WHERE code_location = OLD.code_location;
END;