授權
權限種類
privileges: select, insert, update, delete, all privileges
授權語句
grant <privilege list>
on <relation name or view name>
to <user list>
其中<user list>可以是：public, user-id, role
grant select on student to Amit
grant select(ID) on student to Satoshi
權限回收
revoke <privilege list>
on <relation name or view name>
from <user list>
revoke select on department from Amit
revoke select(budget) on department from Satoshi
權限授予圖
大多數(shù)數(shù)據(jù)庫中开仰，級聯(lián)是默認行為拟枚。
可以通過如下語句防止級聯(lián)：
revoke select on department from Amit, Satoshi restrict;
以下語句顯式指定級聯(lián)回收：
revoke select on department from Amit, Satoshi cascade;
以下語句僅僅回收用戶再授權的權限：
revoke grant option for select on department from Amit;
roles
create role Instructor;
grant Instructor to Mr.Wang; 將role授予用戶
grant select on takes to Instrucor; 授予role以takes關系上的select權限
create role dean;
grant Instructor to dean; 將role授予其他role
權限的轉移
獲得了某些形式權限的用戶可能被允許將此授權傳遞給其他用戶薪铜。默認方式下：被授予權限的用戶/role無權再授予。
允許其再授予：grant select on department to Amit with grant option
