http://mysqlserverteam.com/mysql-8-0-grouping-function/
origin - http://www.pipiscrew.com/2017/05/mysql-v8-0-grouping-function/ mysql-v8-0-grouping-function
http://mysqlserverteam.com/mysql-8-0-grouping-function/
origin - http://www.pipiscrew.com/2017/05/mysql-v8-0-grouping-function/ mysql-v8-0-grouping-function