oracle修改字符集utf8 乱码问题

查询服务端字符集
SELECT * FROM NLS_DATABASE_PARAMETERS;

设置客户端windows字符集环境变量NLS_LANG
AMERICAN_AMERICA.UTF8

然后再导入数据

重新打开plsql客户端。

下面是修改字符集
1.关闭数据库

sql>shutdown immediate

2.启动到mount

sql>startup mount;

---下面参数为内存中修改，重启后参数还原
alter session set sql_trace=true;

sql>alter system enable restricted session;

sql>alter system set job_queue_processes=0;

sql>alter system set aq_tm_processes=0;

sql>alter database open;

--这里可以从父集到子集

sql>alter database character set AL32UTF8;

sql>alter database national character set AL16UTF16;

--如果是从子集到父集，需要使用internal_use参数，跳过超子集检测（不然报ORA-12712: new character set must be a superset of old character set和ORA-12717: Cannot issue ALTER DATABASE NATIONAL CHARACTER SET when NCLOB, NCHAR or NVARCHAR2 data exists）

sql>alter database character set internal_use AL32UTF8;

sql>alter database national character set internal_use AL16UTF16;

sql>shutdown immediate;

sql>startup;