SELECT sum(sizeamount) as counts
,[ShopID]
,dateadd(hh, - datepart(hour,downloadtime) % 24 ,downloadtime)
FROM [abc].[dbo].[ShopDownloadAmount]
group by shopid, dateadd(hh, - datepart(hour,downloadtime) % 24 ,downloadtime)
order by dateadd(hh, - datepart(hour,downloadtime) % 24 ,downloadtime)

结果如下
36730    2    2009-12-15 00:00:00.000
72342    2    2009-12-16 00:00:00.000
76858    2    2009-12-17 00:00:00.000
34094    2    2009-12-18 00:00:00.000
58178    2    2009-12-19 00:00:00.000

SELECT count(*),
DateAdd(second, -DatePart(second, clientTime) ,
DateAdd(ms, -DatePart(ms, clientTime), clientTime))
FROM dbo.V_COMBINED
WHERE (sessionId = '122b')
AND (type = N'sys_goodaction')
AND (paraName = 'value')
GROUP BY DateAdd(second, -DatePart(second, clientTime) % 5
,DateAdd(ms, -DatePart(ms, clientTime), clientTime))