轉自：https://blog.csdn.net/a657281084/article/details/49490069
問題：Oracle主服務和監聽器服務已經啟動，使用SQL Plus能夠正常連接，使用PL SQL Developer連接報次錯誤：ORA-12514: TNS: 監聽程序當前無法識別連接描述符中請求的服務。
如圖：
解決：
1.結束OracleOraDb11g_home2TNSListener進程；
2.打開D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1\NETWORK\ADMIN（不同機器目錄可能不同）目錄下的listener.ora文件，添加紅色部分；（添加錯誤的話無法啟動OracleOraDb11g_home2TNSListener服務）
3.啟動OracleOraDb11g_home2TNSListener服務后成功連接。
# listener.ora Network Configuration File: D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1\network\admin\listener.ora
# Generated by Oracle configuration tools.
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = CLRExtProc)
(ORACLE_HOME = D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1)
(PROGRAM = extproc)
(ENVS = "EXTPROC_DLLS=ONLY:D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1\bin\oraclr11.dll")
)
(SID_DESC =
(SID_NAME = ORCL)
(ORACLE_HOME = D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1)
(ENVS = "EXTPROC_DLLS=ONLY:D:\DevInstall\Oracle11gR2\Administrator\product\11.2.0\dbhome_1\bin\oraclr11.dll")
)
)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
)
)
ADR_BASE_LISTENER = D:\DevInstall\Oracle11gR2\Administrator
SID查看請參照此圖：
