mysql 触发事件指导一下

#因为考虑查询速度,我在order1表中重复了 project_info 表中的部分字段
#project_info表,order1表 是关联的
#所以project_info表的特定字段内容改变时,order1表中(一对多外键)关联数据行的相同字段内容应同时更改
#但是代码不会写,请帮写一下
CREATE TRIGGER update_info AFTER UPDATE ON project_info.name project_info.title 
FOR EACH ROW BEGIN
 UPDATE order1 SET order1.name='', order1.title =''

END;

加在特定的列上的话，参考

CREATE TRIGGER `update_info` AFTER UPDATE ON project_info FOR EACH ROW
BEGIN
   IF !(NEW.name <=> OLD.name) || !(NEW.title <=> OLD.title)  THEN
        UPDATE order1
        SET  name= NEW.name
           , title= NEW.title
        WHERE id = NEW.id;

   END IF;
END
/

参考

CREATE TRIGGER `update_info` AFTER UPDATE ON project_info FOR EACH ROW
BEGIN
    UPDATE order1
    SET  name= NEW.name
       , title= NEW.title
    WHERE id = NEW.id;
END
/