1.运行db的sqlplus：sqlplus sys/sys as sysdba （sys/sys为“用户名”/“密码”）
   或配置client的监听后运行Client的sqlplus

2. （可省略）查看当前服务名：SQL> show parameter service_name

3. 修改服务名：SQL> alter system set service_names='orcl' scope=both;

4. 修改listener.ora（红色部分）：
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = E:\Oracle10g)
      (PROGRAM = extproc)
    )
   (SID_DESC =
    (GLOBAL_DBNAME = ORCL)
    (ORACLE_HOME = E:\Oracle10g)
    (SID_NAME = ORCL)
    )
 )
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
      (ADDRESS = (PROTOCOL = TCP)(HOST = onest)(PORT = 1521))
    )
  )

 

转自：https://blog.csdn.net/huronzhu/article/details/37047819