mysql触发器怎么输出_mysql触发器怎么编写?

-- 1建表

CREATE TABLE test_update_trigger (

id int(10) NOT NULL AUTO_INCREMENT,

age varchar(10) DEFAULT NULL,

PRIMARY KEY (id)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 comment '测试触发器';

CREATE TABLE test_log (

id int(10) NOT NULL AUTO_INCREMENT,

`update_id` int(10) not null default 0 comment '修改id',

log_text varchar(100) DEFAULT NULL,

PRIMARY KEY (id),

key(update_id)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 comment '日志';

-- 2插入数据

insert into test_update_trigger values(1,10),(2,20);

-- 3设置触发器

create trigger tri_test_update

after update on test_update_trigger

for each row

begin

insert into test_log(update_id,log_text) values(NEW.id,concat(cast(NEW.age as char),'修改为：',cast(OLD.age as char)));

end

-- 4修改

update test_update_trigger set age=30 where id=2;

-- 5查询结果

select * from test_log;

id update_id log_text

1 2 30修改为：20