1 创建用户
SQL> create user dog identified by wangwang;

用户已创建。

2 授权给用户
SQL> grant create session,select any table,create table,create view
  2  to dog;

授权成功。

3 收回权限
SQL> revoke create view from dog;

撤销成功。

4 查看权限
SQL> select * from dba_sys_privs
  2  where grantee='DOG';

GRANTEE                        PRIVILEGE                                ADM
------------------------------ ---------------------------------------- ---
DOG                            CREATE SESSION                           NO
DOG                            SELECT ANY TABLE                         NO
DOG                            CREATE TABLE                             NO

，用自己的权限
SQL> show user
USER 为 "DOG"
SQL> select * from session_privs;

PRIVILEGE
----------------------------------------
CREATE SESSION
CREATE TABLE
SELECT ANY TABLE

5 授权时带有with admin option,可以把该权限赋予其他用户
SQL> grant create view to dog with admin option;

授权成功。
SQL> connect dog/wangwang
已连接。
SQL> grant create view to cat;

授权成功。

6 把脚本DBMS_SPACE_ADMIN执行权限赋予System用户
SQL> grant execute on DBMS_SPACE_ADMIN to system;

授权成功。

SQL> l
  1* grant execute on DBMS_SPACE_ADMIN to system
SQL> select * from dba_tab_privs
  2  where privilege like 'EX%'
  3  and table_name like 'DBMS_SPACE_ADMIN%';

GRANTEE                        OWNER
------------------------------ ------------------------------
TABLE_NAME                     GRANTOR
------------------------------ ------------------------------
PRIVILEGE                                GRA HIE
---------------------------------------- --- ---
SYSTEM                         SYS
DBMS_SPACE_ADMIN               SYS
EXECUTE                                  NO  NO

7 把某表的权限授予所有用户
SQL> grant select on risenet_jxfgw.risenet_employee to public;

授权成功。

8.对象权限的回收是级连的，系统权限的回收不是级连的。怎么理解呢？
 对象权限：如表对象的权限 grant select on emp to dog with admin option. 当用户dog同样把权

限给用户cat,grant select on emp to cat with admin option .当管理员sys用户收回用户dog的权限

，用户cat也没有查询emp表的权限了。

系统权限：如表对象的权限 grant select any table to dog with admin option. 当用户dog同样把

权限给用户cat,grant select any table to cat with admin option .当管理员sys用户收回用户dog

的权限，用户cat还可以查询任一表的权限。