ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务

  建立了数据库,名为Demo,并且配置了监听,端口为1521,一切正常运行.今天我又建立了个数据库,名为ORCL,和Demo共用一个监听.
现在遇到一个问题,我每一次用sqlplus sys/orcl@orcl as sysdba  登录没有问题,但是我执行SHUTDOWN IMMEDIATE后,再用sqlplus sys/orcl@orcl as sysdba 登录,就不行了,

C:\>sqlplus sys/orcl@orcl as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on 星期二 12月 30 13:02:30 2008

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

ERROR:
ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务


但是用 sqlplus sys/orcl as sysdba 登录就可以,不知道这是什么,另一个库DEMO 一切正常.
为什么用sqlplus sys/orcl@orcl as sysdba 不行,用sqlplus sys/orcl as sysdba 就可以登录呢？listener.ora和tnsnames.ora如下

listener.ora
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = demo)
      (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)
    )
  )

LISTENER =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = Colin)(PORT = 1521))
  )

tnsnames.ora

DEMO =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = Colin)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = demo)
    )
  )

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = Colin)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST=
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

解决办法是把listener.ora改为如下：

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (GLOBAL_DBNAME = demo)
      (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)
      (SID_NAME = demo)
    )
    (SID_DESC =
      (GLOBAL_DBNAME = ORCL)
      (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)
      (SID_NAME = ORCL)
    )
  )

LISTENER =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = Colin)(PORT = 1521))
  )

重启下监听

还有类似的一个问题解决办法：
昨天配置了oracle数据库,出现TNS问题

问题描述:     当配置完listener和tnsname后,在确认listener服务有正常启动的前提下,在sqlplus下尝试连接数据库,返回以下错误: ORA-12514: TNS:监听程序当前无法识别连接描述符中请求的服务 ORA-12514: TNS:listener does not currently know of service requested in connect descriptor 解决方法: 在listener.ora文件中添加以下内容: (SID_DESC = (GLOBAL_DBNAME = orcl) (ORACLE_HOME = D:\oracle\product\10.2.0\db_1) (SID_NAME = orcl) ) 注意:orcl为数据库名,D:\oracle\product\10.2.0\db_1为$ORACLE_HOME的路径,修改后的listener.ora文件内容如下: # listener.ora Network Configuration File: e:\oracle\product\10.1.0\Db_1\network\admin\listener.ora # Generated by Oracle configuration tools. SID_LIST_LISTENER =   (SID_LIST =     (SID_DESC =       (SID_NAME = PLSExtProc)       (ORACLE_HOME = e:\oracle\product\10.1.0\Db_1)       (PROGRAM = extproc)     )   (SID_DESC =     (GLOBAL_DBNAME = orcl)       (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)       (SID_NAME = orcl)     )   ) LISTENER =   (DESCRIPTION_LIST =     (DESCRIPTION =       (ADDRESS_LIST =         (ADDRESS = (PROTOCOL = TCP)(HOST = linewell-d29e66.mshome.net)(PORT = 1521))       )       (ADDRESS_LIST =         (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))       )     )   ) 相关说明: Cause: The listener received a request to establish a connection to a database or other service. The connect descriptor received by the listener specified a service name for a service (usually a database service) that either has not yet dynamically registered with the listener or has not been statically configured for the listener. This may be a temporary condition such as after the listener has started, but before the database instance has registered with the listener. Action: - Wait a moment and try to connect a second time. - Check which services are currently known by the listener by executing: lsnrctl services <listener name> - Check that the SERVICE_NAME parameter in the connect descriptor of the net service name used specifies a service known by the listener. - If an easy connect naming connect identifier was used, check that the service name specified is a service known by the listener. - Check for an event in the listener.log file.