oracle 使用 ROUND 和 EXTRACT 操作日期

SQL> select to_char(sysdate,'yyyy/mm/dd hh24:mi:ss') "date",  2  extract(YEAR FROM SYSDATE) "year",  3  extract(MONTH FROM SYSDATE) "month",  4  extract(DAY FROM SYSDATE) "day",  5  extract(HOUR FROM SYSTIMESTAMP) "hour",  6  extract(MINUTE FROM SYSTIMESTAMP) "minute",  7  extract(SECOND FROM SYSTIMESTAMP) "second"  8  from dual;--HOUR 匹配的结果没有加上时区，因此在中国运行的结果小8小时date                      year   month     day    hour  minute     second------------------- ---------- ------- ------- ------- ------- ----------2012/04/03 18:53:42       2012       4       3   10         53      42.79

?