network\admin\tnsnames.ora)。TNS_ADMIN=D:\oracle\product\11.2.0\client_1\network\admin,重啟 PLSQL Developer。tnsnames.ora 確保服務配置正確:ORCL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl)
)
)ORCL,輸入用戶名/密碼測試連接。ORA-12154: TNS:could not resolve the connect identifier specified → tnsnames.ora 中服務名拼寫錯誤,或 TNS_ADMIN 指向錯誤目錄。ORA-12541: TNS:no listener → 目標主機 1521 端口不可達,檢查防火牆、Listener 狀態。