MySQL触发器

DROP TABLE IF EXISTS `zt_bug`;
create table `zt_bug` (
  `bug_id` int(10) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL,
  `content` text NOT NULL,
  `username` int(10) DEFAULT ‘0‘,
  PRIMARY KEY (`id`)

)


DROP TABLE IF EXISTS `zt_info`;
CREATE TABLE `zt_info` (
  `info_id` int(10) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) NOT NULL,
  `account` varchar(255) NOT NULL,
  `status` int(10) DEFAULT ‘0‘,
  `id_n` int(10) NOT NULL,
  `type` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) CHARSET=utf8;


创建触发器

作用：增加zt_bug表记录后自动将记录增加到zt_info表中
delimiter $     //mysql中修改命令结束符delimiter
DROP TRIGGER IF EXISTS bug_info_add_trigger;
CREATE TRIGGER bug_info_add_trigger
AFTER INSERT ON zt_bug
FOR EACH ROW
BEGIN
	insert into zt_info(title, account, id_n, type, status) values (new.title, new.username, new.bug_id, ‘bug‘, 0);
END$
delimiter ;

作用：删除zt_bug表记录后自动将删除zt_info表中对应的记录
delimiter $
DROP TRIGGER IF EXISTS bug_info_delete_trigger;
CREATE TRIGGER bug_info_delete_trigger
AFTER DELETE ON zt_bug
FOR EACH ROW
BEGIN
	DELETE FROM zt_info where info_id = old.bug_id
END$
delimiter ;

作用：g更新zt_bug表记录后自动将更新zt_info表中对应的记录
delimiter $
DROP TRIGGER IF EXISTS bug_info_update_trigger;
CREATE TRIGGER bug_info_update_trigger
AFTER UPDATE ON zt_bug
FOR EACH ROW
BEGIN
	UPDATE zt_info SET title = new.title, account = new.username WHERE info_id = (SELECT bug_id FROM zt_bug where title = new.title);
END$
delimiter ;