触发器的操作

##触发器的操作###创建执行一条语句的触发器CREATE TRIGGER trigger_nameBEFORE|AFTER trigger_eventON table_name FOR EACH ROWtrigger_STMT(有关触发事件的操作)eg：CREATE TRIGGER trigger_diarytimeBERORE INSERTON t_dept FOR EACH ROWINSERT INTO t_diaryVALUES(NULL,'t_dept',now());校验INSERT INTO t_deptVALUES(1,'CJIKOAD','SGANG');SELECT *FROM t_diary;注意：只要在表t_dept上执行INSERT操作，就会在t_diary表上执行INSERT INTO t_diary VALUES(NULL,'t_dept',now());#创建执行多条语句的触发器DELIMITER $$CREATE TRIGGER trigger_nameBEFORE|AFTER trigger_eventON table_name FOR EACH ROWBEGINtrigger_STMT1;trigger_STMT2;......trigger_STMTn;END$$DELIMITER;eg:DELIMITER $$CREATE TRIGGER trigger_diarytimeAFTER INSERTON t_dept FOR EACH ROWBEGININSERT INTO t_diaryVALUES(NULL,'t_dept',now());INSERT INTO t_diaryVALUES(NULL,'t_dept',now());END$$DELIMITER;#查看触发器SHOW TRIGGER;SELECT * FROM triggers;SELECT * FROM triggersWHERE TRIGGER_NAME='trigger_name';#删除触发器DROP TRIGGER trigger_name;