近日在ORACLE上做实验，手工创建一个数据库，报了以下错误，无论怎么改字符集都不起作用？不知是什么原因引起的？
CREATE DATABASE mandb
USER SYS IDENTIFIED BY a
USER SYSTEM IDENTIFIED BY a
LOGFILE GROUP 1 ('/u01/ora10g/oradata/redo01.log') SIZE 50M,
GROUP 2 ('/u01/ora10g/oradata/mandb/redo02.log') SIZE 50M,
GROUP 3 ('/u01/ora10g/oradata/redo03.log') SIZE 50M
MAXLOGFILES 5
MAXLOGMEMBERS 5
MAXLOGHISTORY 1
MAXDATAFILES 100
MAXINSTANCES 1
CHARACTER SET AL32UTF8
NATIONAL CHARACTER SET AL32UTF8
DATAFILE '/u01/ora10g/oradata/system01.dbf' SIZE 200M
EXTENT MANAGEMENT LOCAL
SYSAUX DATAFILE '/u01/ora10g/oradata/sysaux01.dbf' SIZE 200M
DEFAULT TABLESPACE tbsp1
DEFAULT TEMPORARY TABLESPACE temp1
TEMPFILE '/u01/ora10g/oradata/temp01.dbf'
SIZE 20M
UNDO TABLESPACE undo1
DATAFILE '/u01/ora10g/oradata/undotbs01.dbf'
SIZE 100MAUTOEXTEND ON MAXSIZE UNLIMITED;
// *
ERROR at line 14:
ORA-12714: invalid national character set specified
oerr ora 12714
12714, 00000, "invalid national character set specified"
// *Cause: Only UTF8 and AL16UTF16 are allowed to be used as the national
// character set
// *Action: Ensure that the specified national character set is valid
