按日期(小时)的SQL组

Question

我有一个带有"日期"列的表.我想按小时分组到特定日期.

Answer 1

你也可以这样做:

SELECT TRUNC(datecol, 'HH24') FROM mytable
GROUP BY TRUNC(datecol, 'HH24');

Answer 2

Select TO_CHAR(date,'HH24')
from table
where date = TO_DATE('20110224', 'YYYYMMDD')
group by TO_CHAR(date,'HH24')

Answer 3

select to_char(datecol,'HH24') thehour, count(*) count_in_hour
from tbl
where datecol = date '20110224'
group by to_char(datecol,'HH24')
order by thehour asc