mysql用戶權(quán)限

授權(quán)該用戶所有權(quán)限，只能本機(jī)登錄: 

grant all  on databasename.tablename to username@localhost Identified by "password"; 

flush privileges; 

注:databasename指數(shù)據(jù)庫名 tablename 表名 全部表可以用* username 用戶名 password 密碼 

授權(quán)該用戶部分權(quán)限，只能某個IP段登錄： 

grant SELECT,INSERT,UPDATE,DELETE,CREATE,DROP on cbc.* to username@'192.168.1.0/255.255.255.0' Identified by "password"; 

取消授權(quán): 

revoke all privileges on *.* from mastert@'%'   

問題：如何關(guān)閉MYSQL某用戶禁止備份還原？