--查看oracle数据库字符集：
select userenv('language') from dual;

查询结果：

SIMPLIFIED CHINESE_CHINA.AL32UTF8

--修改oracle数据库字符集：（在SQL Plus中）

sql> conn / as sysdba;
sql> shutdown immediate;<!--IWMS_AD_BEGIN-->

?

total system global area? 135337420 bytes
fixed size????????????????????????? 452044 bytes
variable size???????????????????? 109051904 bytes
database buffers????????????? 25165824 bytes
redo buffers????????????????????? 667648 bytes
database mounted.

sql> alter system enable restricted session;

system altered.

sql> alter system set? job_queue_processes=0;

system altered.

sql> alter system set? aq_tm_processes=0;

system altered.

sql> alter database open;

database altered.

sql> alter database character set internal_use JA16SJIS;

sql> shutdown immediate;

sql> startup;