最近在做项目中 遇到了oracle数据库中查出来汉字全是乱码，因为字符集不一致，所以要修改自己oracle的字符集，具体步骤如下：
通过ORACLE的SQL PLUS命令窗口改
在SQL*PLUS 中，以DBA登录
conn 用户名 as sysdba
然后执行以下命令
>shutdown immediate; (把database停了)
>startup mount; (把database重开去可更改情況)
>alter system enable restricted session;
>alter system set job_queue_processes=0;
>alter system set aq_tm_processes=0;
>alter database open;
>alter database character set utf8;
执行上面这行可能会报错:
ALTER DATABASE CHARACTER SET ZHS16GBK ERROR at line 1:
ORA-12712: new character set must be a superset of old character set
解决办法:
>ALTER DATABASE character set INTERNAL_USE utf8;
>shutdown immediate;
>startup; (重开正常oracle)
最后在注册表找到：
HKEY_LOCAL_MACHINE -> SOFTWARE ->Oracle->KEY_XE-> 右边窗体点击 NLS_LANG -> 将目标字符集写在里面即可 "AMERICAN_AMERICA.UTF8" ->OK ->CLOSE REGISTRY
重启监听和服务