ORA-12504:oracle连接错误

这个是我的tnsnames.ora的配置，参考下：

SID_LIST_LISTENER =

(SID_LIST =

(SID_DESC =

(SID_NAME = PLSExtProc)

(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)

(PROGRAM = extproc)

)

(SID_DESC =

(GLOBAL_DBNAME = sidb26)

(ORACLE_HOME = /u01/app/oracle/product/11.2.0/dbhome_1)

(SID_NAME = sidb26)

)

)

LISTENER =

(DESCRIPTION_LIST =

(DESCRIPTION =

(ADDRESS = (PROTOCOL = TCP)(HOST = localhost.localdomain.com)(PORT = 1521))

)

)

客户端配置好服务名后，用PL/SQL Developer连接数据库时，报错：ORA-12504：TNS：监听程序在CONNECT_DATA中未获得SERVICE_NAME。一般这种情况请检查tnsnames.ora文件中TNS是否配置正确，如下所示，SERVICE_NAME 名字弄错了，结果报如上错误：

GSP =

(DESCRIPTION =

(ADDRESS =(PROTOCOL = TCP)(HOST = 172.20.36.79)(PORT = 1521))

(CONNECT_DATA=

(SERVER = DEDICATED)

(SERVER_NAME = gsp)

)

)

修改为

GSP =

(DESCRIPTION =

(ADDRESS =(PROTOCOL = TCP)(HOST = 172.20.36.79)(PORT = 1521))

(CONNECT_DATA=

(SERVER = DEDICATED)

(SERVICE_NAME = gsp)

)

)

你确定你的服务器上得 监听 listener 启动了？

查看下是否启动了，命令行中输入

lsnrctl status

如果没启动则

lsnrctl start

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