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)) 
        ) 
    )