我在我的开发机器上本地运行了一个 Oracle 11g 实例，并且可以通过 SqlPlus 直接连接到本地实例：
c:\>sqlplus ace
SQL*Plus: Release 11.2.0.2.0 Production on Mon Mar 11 11:50:20 2013
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Enter password:
Connected to:
Oracle Database 11g Express Edition Release 11.2.0.2.0 - Beta
SQL> select count(*) from my_table ;
COUNT(*)
----------
5297
但我无法通过侦听器连接到它：
c:\>sqlplus -L "user/pw@(DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = XE)))"
SQL*Plus: Release 11.2.0.2.0 Production on Mon Mar 11 11:52:40 2013 …