授权所有的数据库和表给所有的用户
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'passwd' WITH GRANT OPTION;

授权所有的数据库(db)的表(table)给所有的用户
GRANT ALL PRIVILEGES ON db.table TO 'root'@'%' IDENTIFIED BY 'passwd' WITH GRANT OPTION;

刷新数据库
flush privileges;

查询表权限
select User, host from mysql.user;