oracle 时间格式的调整

select * from V$NLS_PARAMETERS; 
SQL> alter session set NLS_DATE_LANGUAGE = 'SIMPLIFIED CHINESE'; 
Session altered 
SQL> Select to_char(sysdate,'yyyy-Mon-day') from dual; 
TO_CHAR(SYSDATE,'YYYY-MON-DAY' 
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2009-5月 -星期三 
SQL> alter session set NLS_DATE_LANGUAGE='AMERICAN'; 
Session altered 
SQL> Select to_char(sysdate,'yyyy-Mon-day') from dual; 
TO_CHAR(SYSDATE,'YYYY-MON-DAY' 
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2009-May-wednesday 
SQL>