1：以sysdba登陆系统，首先创建一个用户
SQL> conn /
as sysdba
Connected.
SQL
>
create user yshy identified by yshy;
User created.
SQL
>
grant connect to yshy;
Grant succeeded.
SQL
>
grant resource to yshy;
Grant succeeded.
SQL
>
grant create synonym to yshy;
Grant succeeded.
SQL
>
2：切换到yshy用户，并创建同义词针对scott.emp
SQL> conn yshy/
yshy
Connected.
SQL
> create synonym y_emp
for
scott.emp;
Synonym created.
3：查询同义词，提示表或视图不存在。
SQL>
select
*
from y_emp;
select
*
from y_emp
*
ERROR at line
1
:
ORA
-
00942
: table or view does not exist
SQL
>
4：登陆scott把emp表的查询权限授权给yshy用户。
SQL> conn scott/
tiger
Connected.
SQL
> grant
select
on emp to yshy;
Grant succeeded.
SQL
> conn yshy/
yshy;
Connected.
SQL
>
select
* from y_emp;
【删除同义词】
DROP [PUBLIC] SYNONYM [schema.]sysnonym_name
