Q:sqlplus连接时报:ORA-12560: TNS:protocol adapter error
A:1:cmd命令行上:
C:\> set ORACLE_SID=orcl
orcl是设置的instance名字
在命令行上连接sqlplus如下:
C:\Documents and Settings\ldwtxwh>sqlplus

SQL*Plus: Release 10.1.0.2.0 - Production on 星期日 12月 20 18:22:28 2009

Copyright (c) 1982, 2004, Oracle. All rights reserved.

Enter user-name: system
Enter password:

Connected to:
Oracle Database 10g Enterprise Edition Release 10.1.0.2.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL>
ok!连接完毕

2:C:\Documents and Settings\ldwtxwh>sqlplus

SQL*Plus: Release 10.1.0.2.0 - Production on 星期日 12月 20 18:33:31 2009

Copyright (c) 1982, 2004, Oracle. All rights reserved.

Enter user-name: sys@orcl SYSDBA
Enter password:

Connected to:

Oracle Database10gEnterpriseEdition Release10.2.0.1.0 - Production

With the Partitioning, OLAP and Data Mining options

SQL>
ok!连接完毕
现在用你的sqlplus就可以连接登陆了.