在linux安装oracle时没有更改默认的字符集。
不支持中文
SQL> select * from t
  2  ;

ID
----------------------------------------------------------------
NAME
--------------------------------------------------------------------------------
1d2a
￡?￡?

1.查看系统字符集
select * from v$nls_parameters
select name,value$ from sys.props$ where name='NLS_CHARACTERSET'
NAME
------------------------------------------------------------
VALUE$
--------------------------------------------------------------------------------
NLS_CHARACTERSET
WE8ISO8859P1

（应该改为ZHS16GBK）
select nls_charset_name(1) from dual;
NLS_CHARSET_NAME
----------------
US7ASCII

2.更改字符集合  （参考了eygle的文章）

（过程不可逆  先备份）

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> STARTUP MOUNT;
ORACLE instance started.

Total System Global Area  285212672 bytes
Fixed Size                  1218992 bytes
Variable Size             104859216 bytes
Database Buffers          176160768 bytes
Redo Buffers                2973696 bytes
Database mounted.
SQL> ALTER SESSION SET SQL_TRACE=TRUE;

Session altered.

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 ZHS16GBK;
ALTER DATABASE CHARACTER SET ZHS16GBK
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set

SQL> ALTER DATABASE CHARACTER SET ZHS16GBK;
ALTER DATABASE CHARACTER SET ZHS16GBK
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set

SQL> ALTER DATABASE CHARACTER SET UTF8
  2  ;
ALTER DATABASE CHARACTER SET UTF8
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set

SQL> ALTER DATABASE CHARACTER SET UTF-8
  2  ;
ALTER DATABASE CHARACTER SET UTF-8
                                *
ERROR at line 1:
ORA-00933: SQL command not properly ended

SQL> ALTER DATABASE CHARACTER SET WE8MSWIN1252;

Database altered.

SQL> COMMIT;

Commit complete.

(可以更改 但是还不支持中文)

SQL> SHUTDOWN IMMEDIATE;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup;
ORACLE instance started.

Total System Global Area  285212672 bytes
Fixed Size                  1218992 bytes
Variable Size             104859216 bytes
Database Buffers          176160768 bytes
Redo Buffers                2973696 bytes
Database mounted.
Database opened.

（看来只能重建实例了）