set @gourpmi = 5

select cast(floor(cast(时间 as float)2460/gourpmi)gourpmi/60/24 as smalldatetime),SUM(字段),Count(字段)
from tb
group by cast(floor(cast(时间 as float)2460/gourpmi)gourpmi/60/24 as smalldatetime)

SQL 按分钟分组