some error of the Oracle connection TNS-03505 OR TNS-12541（原

（原創）配置tnsname是個十分容易的問題，沒什么好說的，以前也從來沒有錯過，不過今天配置的時候出了兩個小問題（這兩個問題是用GUI配置時不會出的，我覺得Java啟動太慢，手工配置tnsname.ora時出現的）
C:\>tnsping 100

TNS Ping Utility for 32-bit Windows: Version 9.2.0.1.0 - Production on 15-OCT-2004 12:38:38

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
F:\oracle\ora92\network\admin qlnet.ora

Used HOSTNAME adapter to resolve the alias
Attempting to contact (DESCRIPTION=(CONNECT_DATA=(SID=*)(SERVICE_NAME=100))(ADDRESS=(PROTOCOL=TCP)(HOST=100)(PORT=1521)))
TNS-12541: TNS:no listener
查看Server端的監聽,lsnrctl status，結果正常

查看tnsname.ora
 100 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.6.100)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = oracas)
    )
  )

完全正確....
*******************************************************************
 或者是
C:\>tnsping 226

TNS Ping Utility for 32-bit Windows: Version 9.2.0.1.0 - Production on 15-OCT-2004 12:40:12

Copyright (c) 1997 Oracle Corporation.  All rights reserved.

Used parameter files:
F:\oracle\ora92\network\admin qlnet.ora

TNS-03505: Failed to resolve name(意思是不存在226在文件tnsname.ora中)
查看tnsname.ora
226 =  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.6.226)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = oracas)
    )
  )
完全正確...

最后分析出導致上述兩個問題的原因都是應為tns前面多了一個空格。。。。。。寒，居然是這種錯誤...
所以大家配置的時候小心細節問題

原文轉自：http://www.kjueaiud.com