方法一：
SQL> create user user1 identified by oracle;
User created.
SQL> grant connect to user1;
Grant succeeded.
SQL> grant select any table to user1;
Grant succeeded.
SQL> grant select any dictionary to user1;
Grant succeeded.
SQL> conn user1/oracle
Connected.
SQL> select * from emp;
select * from emp
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL>
SQL> select * from scott.emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
方法二：
SQL> conn / as sysdba
Connected.
SQL>
SQL> create user user2 identified by oracle;
User created.
SQL> grant connect to user2;
Grant succeeded.
SQL> grant create synonym to user2;
Grant succeeded.
SQL> grant select on scott.emp to user2;
Grant succeeded.
SQL> create or replace synonym user2.emp for scott.emp;
Synonym created.
SQL> conn user2/oracle
Connected.
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7839 KING PRESIDENT 17-NOV-81 5000 10
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
备注：
1.批量授权查询多个表的权限
select 'grant select on '||owner||'.'||object_name||' to user2;' from dba_objects where owner in ('SCOTT') and object_type='TABLE';
2.批量创建同义词
SELECT 'create or replace SYNONYM user2.'||object_name||' FOR '||owner||'.'||object_name||';' from dba_objects where owner='SCOTT' and object_type='TABLE';
总结，方法一用户查询数据的时候仍然要在表名前添加schema才可以查询，方法二使用创建同义词的方法，在查询的时候不需要添加schema，生产上一般使用方法二创建最小查询权限用户。
