C:\Users\yan>sqlplus / as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Sun Nov 12 12:04:24 2017

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

ERROR:
ORA-12560: TNS:protocol adapter error

進入Oracle安裝目錄執行：

C:\Users\yan>cd /d D:\oraclexe\app\oracle\product\11.2.0\server\bin

D:\oraclexe\app\oracle\product\11.2
 
.0\server\bin>sqlplus / as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Sun Nov 12 12:07:31 2017

Copyright (c) 1982, 2010, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - Production

SQL>

ERROR: ORA-12560: TNS:protocol adapter error