oracle 獲取時間

1、獲取當前時間的前24小時的各小時時間段

select
    to_char(to_date(to_char(sysdate - (rownum - 1) / 24,'yyyy-mm-dd hh24')
                        || ':00:00','yyyy-mm-dd hh24:mi:ss'),'yyyy-mm-dd hh24:mi:ss') totaldate
from
    dual
connect by
    rownum <= 24
order by
    totaldate desc

 

2、獲取某天的0點到24點的各小時時間段

select
    TO_CHAR(to_date('2019-01-28','yyyy-mm-dd') + (rownum - 1) / 24,'yyyy-mm-dd hh24:mi:ss') TIMES
from
    DUAL
connect by
    level <= 24

 3、獲取0點到當前時間的小時段

select
    TO_CHAR(to_date('2019-01-28','yyyy-mm-dd') + (rownum - 1) / 24,'yyyy-mm-dd hh24:mi:ss') TIMES
from
    DUAL
connect by
    level <=  to_char(sysdate + 1 / 24,'hh24')