查看用户当前权限
show grants;
查看其他 MySQL 用户权限：
show grants for ‘<username>‘@‘<host>‘;
授权
grant <privileges> on <databasename.tablename> to ‘<username>‘@‘<host>‘ identified by ‘<123>‘;
identified by非必须。
撤销权限
revoke <privileges> on <databasename.tablename> from ‘<username>‘@‘<host>‘;
privileges：
全部权限：all privileges
其他权限参考：
https://www.cnblogs.com/fslnet/p/3143344.html
http://blog.csdn.net/wulantian/article/details/38230635
