在安装完Oracle10g后，使用PL/SQL工具连接，提示如下的问题：
ORA-12514: TNS: 监听程序当前无法识别连接描述符中请求的服务
 
 
解决办法是手动修改监听配置文件：
 
# listener.ora Network Configuration 
File: d:\oracle\product\10.2.0\client_1\network\admin\listener.ora 

# Generated 
by Oracle configuration tools. 


SID_LIST_LISTENER = 

    (SID_LIST = 

        (SID_DESC = 

            (SID_NAME = PLSExtProc) 

            (ORACLE_HOME = d:\oracle\product\10.2.0\client_1) 

            (PROGRAM = extproc) 

        ) 

        (SID_DESC =    
            (GLOBAL_DBNAME = ORCL)    
            (ORACLE_HOME = G:\oracle\product\10.2.0\db_1)        
            (SID_NAME = ORCL)    
        )    
    ) 

LISTENER = 

    (DESCRIPTION_LIST = 

        (DESCRIPTION = 

            (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.100)(PORT = 1521)) 

            (ADDRESS = (PROTOCOL = IPC)(
KEY = EXTPROC0)) 

        ) 

    )
 
其中红色粗体部分是添加部分。
 
以上是在一台机器上既安装了Oracle服务器，又安装了客户端的情况。
 
 
下面是仅仅在一台机器上安装了服务器，并且是在服务器本机上安装PLSQL使用Oracle数据库的情况：
# listener.ora Network Configuration File: E:\oracle\product\10.2.0\db_1\network\admin\listener.ora 

# Generated by Oracle configuration tools. 


SID_LIST_LISTENER = 

    (SID_LIST = 

        (SID_DESC = 

            (SID_NAME = PLSExtProc) 

            (ORACLE_HOME = E:\oracle\product\10.2.0\db_1) 

            (PROGRAM = extproc) 

        ) 

        (SID_DESC =         
            (GLOBAL_DBNAME = ORCL)         
            (ORACLE_HOME = E:\oracle\product\10.2.0\db_1)                 
            (SID_NAME = ORCL)         
        )         

    ) 


LISTENER = 

    (DESCRIPTION_LIST = 

        (DESCRIPTION = 

            (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1)) 

            (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) 

        ) 

    )