oracle日期函数备忘

1.返回下一个星期一对应的日期
  Select NEXT_DAY(sysdate,'星期一') From dual;

2.返回星期几
  select to_char(sysdate,'DAY') as weekday from dual;

3.根据星期几排序
  从星期天开始(1代表星期天)
  select time,to_char(begintime,'d') from t order by to_char(time,'d');
  从星期一开始
  select begintime,trim(to_char(t.begintime, 'DAY')) dd,decode(trim(to_char(t.time, 'DAY')),
                 'MONDAY',
                 1,
                 'TUESDAY',
                 '2',
                 'WEDNESDAY',
                 '3',
                 'THURSDAY',
                 '4',
                 'FRIDAY',
                 '5',
                 'SATURDAY',
                 '6',
                 'SUNDAY',
                 '7') from t
order by 3 ;