查看用户权限

show grants for root@host;

授权：

 GRANT ALL PRIVILEGES ON *.* TO 'root'@'host' IDENTIFIED BY  'password';

撤销权限：

REVOKE ALL PRIVILEGES FROM

查看哪些用户在哪些host上有‘GRANT OPTION’权限

select Host,User,Grant_priv from mysql.user where Grant_priv='Y';