在安装oralce时没有配置全局数据库，安装完成后，创建了一个oracle数据库，但是在使用PL/SQL连接时，出现如下错误：

??? ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务

?解决方法（引自http://timke.blog.163.com/blog/static/101587306201042695856670/）：

??? 修改

listener.ora

??? SID_LIST_LISTENER =
?????? (SID_LIST =
????????? (SID_DESC =
??????????? ?(SID_NAME = PLSExtProc)
???????????? (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)
??????????? ?(PROGRAM = extproc)
????????? ?)
???????? ?(SID_DESC =
????????????? (GLOBAL_DBNAME = oracle)
???????????? (ORACLE_HOME = D:\oracle\product\10.2.0\db_1)??
???????????? (SID_NAME = oracle)
??????? ? )
?????? )

LISTENER =
? (DESCRIPTION_LIST =
??? (DESCRIPTION =
????? (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1))
????? (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
??? )
? )

将红色部分添加到listener.ora中，重启监听器服务。

?