oracle链接的配置--product\11.2.0\client_1\network\admin\tnsnames.ora

oracle客户端安装路径\product\11.2.0\client_1\network\admin\tnsnames.ora
其内容如下：

# tnsnames.ora Network Configuration File: E:\Oracle11g-client2-manager\product\11.2.0\client_1\NETWORK\ADMIN\tnsnames.ora
# Generated by Oracle configuration tools.

DEV =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.71)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = DEV)
)
)

CESHISTU =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.71)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)

MYORCL =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)

以这个为例：
CESHISTU =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.71)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)
这里CESHISTU是服务名，我干脆叫它连接的别名，因为特很容易和数据库实例名混淆。
这个名字可以随便起，它最终在pl/sql的第三个下拉框数据库显示，而真正确定
连接哪个数据库的是SERVICE_NAME = orcl。这个orcl才是数据库实例名。它的连接地址
是：(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.30.71)(PORT = 1521))。

这些东西当然有相关的管理客户端去设置，否则每个人都要学习这个文件的配置，那就
太不人性化了。你可以在配置和移植工具里的Net Manager里配置这些内容，其实质就是
在这个文件写这些东西，所以你明白原理以后，配置会更快，更准确。