dblink 使用说明

转载自：http://apple-wxs.javaeye.com/blog/281072

 

如果想从主机A 操作主机B 上的数据，可以在主机A上建立一个dblink，link到主机B上，从而操作主机B上的数据。

主机A的tnsnames.ora中配置了主机B的信息

TEST =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.134)(PORT = 1521))
    (CONNECT_DATA =
      (SERVICE_NAME = bs)
      (INSTANCE_NAME = bs)
    )
  )

TEST =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.134)(PORT = 1521))
    (CONNECT_DATA =
      (SERVICE_NAME = bs)
      (INSTANCE_NAME = bs)
    )
  )

注：sid：TEST   服务名：bs（通过sid能知道连接的IP,端口）

建立dblink的语法：
create database link link名
connect to 登陆主机B的用户名（没有引号） identified by 登陆主机B的密码
using '主机B在主机A中的tnsnames.ora中配置的sid';

--删除dblink
drop database link link_test;
--建立dblink
create database link link_test
connect to apple_wxs identified by apple_wxs
using 'TEST';
--查询主机B 上的XXX_t表
select * from XXX_t@link_test;

--删除dblink
drop database link link_test;
--建立dblink
create database link link_test
connect to apple_wxs identified by apple_wxs
using 'TEST';
--查询主机B 上的XXX_t表
select * from XXX_t@link_test;

主机A上的tnsnames.ora中没有配置主机B的sid或不知道的情况

CREATE PUBLIC DATABASE LINK  link名
CONNECT TO username IDENTIFIED BY password
USING '(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.2.134)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = bs)
)
)';