环境描述：
Linux 7.0 + Oracle 12C
问题描述：
将数据库NLS_CHARACTERSET与NLS_CHARACTERSET修改：
NLS_CHARACTERSET（是数据库字符集）由AL32UTF8 修改为ZHS16GBK
NLS_NCHAR_CHARACTERSET(是国家字符集) 由AL16UTF16 修改为UTF8
解决办法：
代码：
conn /as sysdba
shutdown immediate;
startup mount
ALTER SESSION SET sql_TRACE=TRUE;
ALTER SYSTEM ENABLE RESTRICTED SESSION;
ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
ALTER SYSTEM SET AQ_TM_PROCESSES=0;
ALTER DATABASE OPEN;
----NLS_CHARACTERSET是数据库字符集
ALTER DATABASE CHARACTER SET ZHS16GBK;
ALTER DATABASE CHARACTER SET INTERNAL_USE ZHS16GBK;
--NLS_NCHAR_CHARACTERSET是国家字符集
ALTER DATABASE NATIONAL CHARACTER SET INTERNAL_USE UTF8;
ALTER SESSION SET sql_TRACE=FALSE;
select * from v$nls_parameters;
SELECT parameter,value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET';
shutdown immediate;
startup
shutdown immediate;
startup mount
ALTER SESSION SET sql_TRACE=TRUE;
ALTER SYSTEM ENABLE RESTRICTED SESSION;
ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
ALTER SYSTEM SET AQ_TM_PROCESSES=0;
ALTER DATABASE OPEN;
----NLS_CHARACTERSET是数据库字符集
ALTER DATABASE CHARACTER SET ZHS16GBK;
ALTER DATABASE CHARACTER SET INTERNAL_USE ZHS16GBK;
--NLS_NCHAR_CHARACTERSET是国家字符集
ALTER DATABASE NATIONAL CHARACTER SET INTERNAL_USE UTF8;
ALTER SESSION SET sql_TRACE=FALSE;
select * from v$nls_parameters;
SELECT parameter,value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET';
shutdown immediate;
startup
操作如下：
sql> conn / as sysdba
Connected.
sql> SELECT parameter,value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET';
PARAMETER
----------------------------------------------------------------
VALUE
----------------------------------------------------------------
NLS_CHARACTERSET
AL32UTF8
NLS_NCHAR_CHARACTERSET
AL16UTF16
sql> conn / as sysdba
Connected.
sql> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
sql> startup mount
ORACLE instance started.
Total System Global Area 4999610368 bytes
Fixed Size 5293944 bytes
Variable Size 1258293384 bytes
Database Buffers 3724541952 bytes
Redo Buffers 11481088 bytes
Database mounted.
sql> ALTER SESSION SET sql_TRACE=TRUE;Session altered.
sql> ALTER SYSTEM ENABLE RESTRICTED SESSION;
System altered.
sql> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
System altered.
sql> ALTER SYSTEM SET AQ_TM_PROCESSES=0;
System altered.
sql> alter database open;
Database altered.
sql> ALTER DATABASE CHARACTER SET ZHS16GBK;
ALTER DATABASE CHARACTER SET ZHS16GBK * ERROR at line 1: ORA-12712: new character set must be a superset of old character set sql> ALTER DATABASE CHARACTER SET INTERNAL_USE ZHS16GBK; Database altered. sql> ALTER DATABASE NATIONAL CHARACTER SET INTERNAL_USE UTF8; Database altered. sql> ALTER SESSION SET sql_TRACE=FALSE; Session altered. sql> SELECT parameter,value FROM v$nls_parameters WHERE parameter LIKE '%CHARACTERSET'; PARAMETER ---------------------------------------------------------------- VALUE ---------------------------------------------------------------- NLS_CHARACTERSET ZHS16GBK NLS_NCHAR_CHARACTERSET UTF8 sql> shutdown immediate; Database closed. Database dismounted. ORACLE instance shut down. sql> startup ORACLE instance started. Total System Global Area 4999610368 bytes Fixed Size 5293944 bytes Variable Size 1258293384 bytes Database Buffers 3724541952 bytes Redo Buffers 11481088 bytes Database mounted. Database opened. 原文链接：https://www.f2er.com/oracle/212884.html
