主要是原来的是gbk的，放到utf8下面，各种长度不够

以下是调整过程：

//查看Pdb

show pdbs;

//删除pdb

drop pluggable database testpdb including datafiles;

//创建pdb

create pluggable database testpdb admin user testpdb identified by testpdb file_name_convert=('/opt/oracle/oradata/ORCLCDB/pdbseed/','/oracle/oradata/testpdb/');

//打开数据库

alter pluggable database testpdb open;

//确认字符集

alter session set container=testpdb;

select userenv('language') from dual;

//修改字符集

alter pluggable database testpdb close immediate instances=all;

alter pluggable database testpdb open read write restricted;

alter database character set internal_use zhs16gbk;

alter pluggable database testpdb close immediate;



--启动pdb确认

alter pluggable database testpdb open instances=all;

alter session set container=testpdb;

select userenv('language') from dual;  <<<<<<<<<<此时字符集已经修改



//切换到cdb

alter session set container=CDB$ROOT;

alter pluggable database all save state;