052-155

The user HR owns the EMP table. The user HR grants privileges to the user SCOTT by using this command:
SQL> GRANT SELECT,INSERT,UPDATE ON emp TO scott WITH GRANT OPTION;
The user SCOTT executes this command to grant privileges to the user JIM:
SQL> GRANT SELECT,INSERT,UPDATE ON hr.emp TO jim;
Now, the user HR decides to revoke privileges from JIM using this command:
SQL> REVOKE SELECT,INSERT,UPDATE ON emp FROM jim;
Which statement is true after HR issues the REVOKE command?
A.The command fails because SCOTT still has privileges.
B.The command succeeds and privileges are revoked from JIM.
C.The command fails because HR cannot revoke the privileges from JIM.
D.The command succeeds and only HR has the privilege to perform the SELECT, INSERT, and UPDATE operations on the EMP table.

hr 将 DML 操作 emp 表的权限给 scott,并且 scott 有传递权限,scott 将此权限传递给 jim,此时 hr 想将 jim 的权限收回,出错,因为 hr 没有授予过权限给 jim,此时 jim 可以 DML 操作 EMP 表,当 hr 将 scott 的权限收回时,jim 不能再查询等操作。
系统权限取消时不级联,对象权限取消时是级联的。

原文地址:https://www.cnblogs.com/Babylon/p/8037718.html