MySQL中的触发器应用

直接上代码:

/*
数据库 - udi_ems_test
*********************************************************************
内容:在plan_material_summary_info总表中删除数据前,对当前数据进行备份,保存至plan_material_summary_info_backup中
*/
DELIMITER $$
USE `udi_ems_test`$$
DROP TRIGGER IF EXISTS `plan_material_summary_info_trigger`$$
CREATE
    /*!50017 DEFINER = 'root'@'%' */
    TRIGGER `plan_material_summary_info_trigger` BEFORE DELETE ON `plan_material_summary_info`
    FOR EACH ROW BEGIN
     INSERT INTO plan_material_summary_info_backup SELECT * FROM plan_material_summary_info WHERE id=old.id;
    END;
$$
DELIMITER ;
具体讲解如下地址:
1.http://blog.sina.com.cn/s/blog_62b080970100nxw1.html(删除前备份数据)
2.https://www.cnblogs.com/duodushu/p/5446384.html(触发器资料)
3.https://blog.csdn.net/tonysong111073/article/details/99286229(实例)