SQL Server is grouped by date and time period (a group of every three hours)

Data sheet used:

1. Group by date

1. Use convert()function method

--根据年月
select convert(varchar(7),CreatTime,120)日期,COUNT(*) 次数,sum(Money)总数 from Orders
group by convert(varchar(7),CreatTime,120)

According to convertthe first parameter of, the length of the result is set to be more grouped by year, month or day, etc.

2017-09 Length 7 varchar(7)

2017-09-01 Length 10 varchar(10)

--根据年月日
select convert(varchar(10),CreatTime,120)日期,COUNT(*) 次数,sum(Money)总数 from Orders
group by convert(varchar(10),CreatTime,120)

2. First find out the corresponding year, month, day, etc., and then group according to the query field

--或者
select YEAR(CreatTime) 年,month(CreatTime) 月,COUNT(*) 次数,sum(Money)总数 from Orders
group by month(CreatTime),YEAR(CreatTime)
order by 年,月 asc

2. Group according to time period (one group every three hours)

dataname: Returns the character string representing the specified date part of the specified date. One parameter represents the returned format, and the second parameter is the specific value

dw: Day of the week, qq, q: quarter, yy, yyyy: year, mm, m: month, dd, d: day, hh: hour, mi, n: minute ss, s: second, ms: millisecond

select CONVERT(varchar(11),convert(varchar(2),datename(hh,CreatTime) / 3 *3)+':00~'+convert(varchar(2),
row_number() over(order by datename(hh,CreatTime) / 3)*3-1)+':59') 时间段
,COUNT(*)次数,sum(Money)总数 from Orders
group by datename(hh,CreatTime) / 3