Oracle连接出现ora-12154无法解析指定的连接标识符

配置好rac后,两个节点用tnsping都可以ping通,但用sqlplus连接都出现以下错误,不知道哪里出了问题
[oracle@rac2 admin]$ lsnrctl status
LSNRCTL for Linux: Version 9.2.0.4.0 - Production on 04-MAR-2008 08:32:26
Copyright (c) 1991, 2002, Oracle Corporation.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 9.2.0.4.0 - Production
Start Date                04-MAR-2008 08:29:03
Uptime                    0 days 0 hr. 3 min. 22 sec
Trace Level               off
Security                  OFF
SNMP                      OFF
Listener Parameter File   /home/oracle/9.2.0.4/work/admin/listener.ora
Listener Log File         /home/oracle/9.2.0.4/work/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=rac2)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "esal" has 2 instance(s).
  Instance "rac1", status READY, has 1 handler(s) for this service...
  Instance "rac2", status READY, has 1 handler(s) for this service...
The mand pleted suessfully
[oracle@rac2 admin]$ lsnrctl service
LSNRCTL for Linux: Version 9.2.0.4.0 - Production on 04-MAR-2008 08:32:32
Copyright (c) 1991, 2002, Oracle Corporation.  All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=rac2)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0
         LOCAL SERVER
Service "esal" has 2 instance(s).
  Instance "rac1", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         REMOTE SERVER
         (address=(protocol=tcp)(host=rac1)(port=1521))
  Instance "rac2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
The mand pleted suessfully
[oracle@rac2 admin]$ sqlplus cy/zh@esal
SQLPlus: Release 9.2.0.4.0 - Production on Tue Mar 4 08:32:45 2008
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.
ERROR:
ORA-12154: TNS:could not resolve service name

Enter user-name:
ERROR:
ORA-01017: invalid username/password; logon denied

Enter user-name: cy/zh@rac1
ERROR:
ORA-12154: TNS:could not resolve service name

SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQLPlus
[oracle@rac2 admin]$ sqlplus cy/zh@rac2
SQLPlus: Release 9.2.0.4.0 - Production on Tue Mar 4 08:32:59 2008
Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.
ERROR:
ORA-12154: TNS:could not resolve service name

Enter user-name:

按照如下过程，一般都能解决
在虚拟机内开cmd，用lsnrctl status查看监听器监听的服务
如看到监听服务“orcl”，那在本机的tns配置中(SERVICE_NAME = orcl)必须写orcl；如果想要自定义，则在虚拟机内的listener配置中就要加入自定义服务名，记得要重启监听服务lsnrctl reload
形成的配置文件如下
虚拟机listener

SID_LIST_LISTENER = 
 (SID_LIST = 
  (SID_DESC = 
   (GLOBAL_DBNAME = test)   自定义服务名 
   (ORACLE_HOME = E:oracleproduct10.2.0db_1) db_home 
   (SID_NAME = test)   
  ) 
  (SID_DESC = 
   (PROGRAM = extproc) 
   (SID_NAME = PLSExtProc) 
   (ORACLE_HOME = E:oracleproduct10.2.0db_1) ##这个服务保证你可以使用外部过程，如C程序 
  ) 
 )

本机tns

ORCL_XNJ = 
 (DESCRIPTION = 
  (ADDRESS_LIST = 
   (ADDRESS = (PROTOCOL = TCP)(HOST = 182.12.15.232)(PORT = 1521)) 
  ) 
  (CONNECT_DATA = 
   (SERVICE_NAME = test) 与自定义服务名对应 
  ) 
 )

连接，问题解决！
记住，一定从最简单的原因找起，不要一上去就看到网上的什么改process数、注册表之类的，要想想本机能连为什么通过网络就不行，还是定位问题。
VS2008连接oracle 出现错误 ora-12154 tns 无法解析指定的连接标示符

在保证你的代码没有错误的前提下
（一）检查OracleOraDb10g_home1TNSListener 服务有没有启动，即监听服务
（二）检查tnsnames.ora是否添加连接串（建议用SQLPLUS或者pl/sql测试），其路径一般是%Oracle_home%product10.2.0db_1NETWORKADMINtnsnames.ora

其它网友的补充

今天装oracle安装都完成了，但出现了“ORA-12154 TNS”的错误，最开始以为是oracle安装处了问题，但后来发现并不是，因为用SQL Plus可以登录，只是用plsql登录时才出现这错，用360完全卸载了qlsql后，从新装了次，还是那错，郁闷。。。后来又把数据库删掉重新建立，还是不行，整了半天，自己都整晕了，算了，重头再来吧。。。
百度下很多安装图解，按着来就成

oracle服务端安装图解

oracle客户端安装图解

oracle完全卸载

或者直接在注册表中按F3搜索oracle，删除注册文件，不过貌似文件有点多，操作有点慢，建议用上边链接的方法

了下要注意的几点

1.安装服务端是一般选“基本安装”就行
2.使用PLSQL Developer时,“ORA-12154 TNS无法解析指定的连接标识符”的问题
安装时报后边的错“warning some oracle versions cannot connect from a path with parentheses”，这错原来提示了，不能有括号，修改了安装路径就没有问题了
相应的上边的“ORA-12154 TNS无法解析指定的连接标识符”错也没啦，有点晕，没整明白，但确实好啦
3.“ORA-12154 TNS无法解析指定的连接标识符”按照网上的方法有两种，但我试了，在我这都不好使，下边贴出来，没准儿啥时候可以用
1.解决办法，修改PLSQL Developer的选项设置
 
客户端、服务器端Oracle软件装好之后，用PLSQL Devloper登录时，点击取消，进入PLSQL Developer主界面，菜单Tools-Preferences，在设置窗口中，选择Oracle-Connection，对应设置窗口中，找到Oracle Home，选择OraDb10g_home1，保存设置，重新登录PLSQL Developer即可

2.修改D:\oracle\product\10.2.0\db_1\NETWORK\ADMIN路径下的tnsnames.ora文件
###### 一般的配置 ##################################

ORALOCAL =
 (DESCRIPTION =
  (ADDRESS_LIST =
   (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
  )
  (CONNECT_DATA =
   (SERVER = DEDICATED)
   (SERVICE_NAME = oralocal)
  )
 )

以上答案供参考