oracle 11g数据库修改字符集
NLS_CHARACTERSET我安装数据库的时候设置为ZHS16GBK，而开发需要的UTF8
据开发反应
向数据库表中插入一条数据的时候，中文就都变了类似于“？（是反问号）”的乱码，
为了能顺利插入成功，故做了此次修改;
查询字符集参数
可以查询以下数据字典或视图查看字符集设置情况
nls_database_parameters、props$、v$nls_parameters
查询结果中NLS_CHARACTERSET表示字符集，NLS_NCHAR_CHARACTERSET表示国家字符集
修改步骤：
SQL> shutdown immediate;
SQL> startup mount;
SQL> alter system enable restricted session;
SQL> alter system set job_queue_processes=0;
SQL> alter database open;
SQL> alter database character set internal_use AL32UTF8(或者是UTF8);
SQL> shutdown immediate;
SQL> startup
SQL>alter system disable restricted session;
再次查看修改好了
SQL> select * from nls_database_parameters;
PARAMETER VALUE
------------------------------ --------------------
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
NLS_CURRENCY $
NLS_ISO_CURRENCY AMERICA
NLS_NUMERIC_CHARACTERS .,
NLS_CHARACTERSET AL32UTF8
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD-MON-RR
NLS_DATE_LANGUAGE AMERICAN
NLS_SORT BINARY
NLS_TIME_FORMAT HH.MI.SSXFF AM
PARAMETER VALUE
------------------------------ --------------------
NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXF
F AM
NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR
NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXF
F AM TZR
NLS_DUAL_CURRENCY $
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE
PARAMETER VALUE
------------------------------ --------------------
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_RDBMS_VERSION 11.2.0.4.0
20 rows selected.
SQL> select userenv('language') from dual;
USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8
