修改oracle系统参数spfile导致数据库无法启动解决

错误示范：

SQL> alter system set nls_date_format='yyyy-mm-dd 24hh:mi:ss' scope=spfile;
System altered.
我更改了数据库的日期格式后，重启后，数据库打开不了了。
ORA-01821: date format not recognized，有没有人知道怎么改回去。
大意 hh24 写成了24hh

解决步骤：

1.可能需要重配netca，启动监听到实例。

2.startup pfile=/u01/app/oracle/admin/orcl/pfile/init.ora.6272016162851;

ORACLE instance started.

Total System Global Area 672256000 bytes
Fixed Size 2216384 bytes
Variable Size 402656832 bytes
Database Buffers 264241152 bytes
Redo Buffers 3141632 bytes
Database mounted.
Database opened.

3.SQL> create spfile from pfile='/u01/app/oracle/admin/orcl/pfile/init.ora.6272016162851';  （重建spfile）

File created.

4.SQL> shutdown normal;

Database closed.
Database dismounted.
ORACLE instance shut down.

 5.SQL> startup;

ORACLE instance started.

Total System Global Area 672256000 bytes
Fixed Size 2216384 bytes
Variable Size 402656832 bytes
Database Buffers 264241152 bytes
Redo Buffers 3141632 bytes
Database mounted.
Database opened.