PLSQL不好用，提示ora-12514 错误解决方法

我的PLSQL不好用，提示ora-12514错误时

我分两步干的：

1：用户名，密码，不写，提示错误后，cancel登陆

tools->preference左侧选->connection,右侧Oracle Home 里面选择OraDb10g_home1。

2：找到%oracle_home%NETWORK/ADMIN/LISTENER.ORA

修改如下：添加一段代码

# listener.ora Network Configuration File: D:/oracle/oracle10g/network/admin/listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = D:/oracle/oracle10g)
(PROGRAM = extproc)
)
(SID_DESC =

(GLOBAL_DBNAME = ORCL)

(ORACLE_HOME = D:/oracle/oracle10g)

(SID_NAME = ORCL)

)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
)
)
)