修改ORACLE数据库字符集为ZHS16GBK

import done in AL32UTF8 character set and AL16UTF16 NCHAR character set
import server uses WE8MSWIN1252 character set (possible charset conversion)
export client uses ZHS16GBK character set (possible charset conversion)

SQL> select userenv('language') from dual;
# 采用的是操作系统默认字符集：WE8MSWIN1252，我这里需要将字符集修改为：ZHS16GBK。
USERENV('LANGUAGE')
--------------------------------------------------------------------------------
AMERICAN_AMERICA.WE8MSWIN1252

# 以管理员身份登录
SQL> sqlplus sys as sysdba
# 关闭数据库
SQL> shutdown immediate
SQL> startup
SQL> alter session set sql_trace=true;
SQL> alter system enable restricted session;
SQL> show parameter job_queue_processes;
SQL> alter system set job_queue_processes=0;
SQL> alter system set aq_tm_processes=0;
SQL> alter database open;
SQL> alter database character set INTERNAL_USE ZHS16GBK;

维护完以后需要
SQL>ALTER SYSTEM DISABLE RESTRICTED SESSION;
改变字符集后，原来已有的数据不会改变，只是之后新增的数据会是新的字符集。

引用自：https://www.cnblogs.com/guo-shuai/p/10811554.html