select to_char(sysdate, 'mon' , 'NLS_DATE_LANGUAGE = American' ) 日期測試 from dual select to_char(sysdate, 'mon' ) 日期測試 from dual select to_char(sysdate, 'dd-mon-yy' , 'NLS_DATE_LANGUAGE = American' ) 日期測試 from dual select to_date( date_time , 'dd-mon-yy' , 'NLS_DATE_LANGUAGE = American' ) 日期測試 from ( select to_char(sysdate, 'dd-mon-yy' , 'NLS_DATE_LANGUAGE = American' ) date_time from dual )