列级安全

我需要一种隐藏表中特定列的解决方案。我们有些人需要针对此数据库（特别是其中一些带有机密信息的表）生成报告，但不允许查看薪水或ssn等项目。是否可以为用户过滤特定的列？

只要涉及的用户还没有访问基表的权限，就可以使用普通视图执行此操作。

例如：

SQL> create user reportuser identified by reportuser;

User created.

SQL> grant create session to reportuser;

Grant succeeded.

SQL> grant create synonym to reportuser;

Grant succeeded.

SQL> select user from dual;

USER
------------------------------
PHIL

SQL> create table basetable
(
  id number primary key,
  viewable varchar2(30),
  secret varchar2(30)
);

Table created.

SQL> insert into basetable values ( 1, 'hello world','this is secret' );

1 row created.

SQL> commit;

Commit complete.

SQL> create view reportview
as
select id, viewable
from basetable;

View created.

SQL> grant select on reportview to reportuser;

Grant succeeded.

SQL> conn reportuser/reportuser
Connected.
SQL> select * from phil.basetable;
select * from phil.basetable
                   *
ERROR at line 1:
ORA-00942: table or view does not exist

SQL> select secret from phil.basetable;
select secret from phil.basetable
                        *
ERROR at line 1:
ORA-00942: table or view does not exist

SQL> select * from phil.reportview;

        ID VIEWABLE
---------- ------------------------------
         1 hello world

SQL>

如果您撤消对相关表的权限并创建视图，并为每个与原始表具有相同名称的用户视图创建同义词，则该视图应该是透明的。

例如：

SQL> select user from dual;

USER
------------------------------
REPORTUSER

SQL> create synonym basetable for phil.reportview;

Synonym created.

SQL> select * from basetable;

        ID VIEWABLE
---------- ------------------------------
         1 hello world

SQL>

您也可以使用Virtual Private Database来做到这一点，但是我认为这是一个昂贵的额外许可选项。您使用DBMS_RLS来配置所需的相关安全策略。