Select 在 sql 中每 15 分钟行一次

Question

 DataType 

      SamplingTime  : Datetime
      Value         : Integer



  SamplingTime          Value
2020-06-08 00:03:58.000 ,  1.00
2020-06-08 00:03:59.000 ,  5.00
2020-06-08 00:02:00.000 ,  3.00
2020-06-08 00:01:58.000 ,  1.00
2020-06-08 00:01:44.000 ,  6.00
2020-06-08 00:01:20.000 ,  2.00

I want Output to get ROW in interval of 15 minutes filter in data should give

Sample Output

2020-06-08 00:03:58.000 ,  1.00
2020-06-08 00:02:00.000 ,  3.00
2020-06-08 00:01:44.000 ,  6.00
2020-06-08 00:01:20.000 ,  2.00

Query which i tried for it:

select dateadd(MINUTE,datediff(MINUTE,-15,SamplingTime),15), value 
from RN_QOS_DATA_0001 

This rowset contain info for dataSet:

Answer 1

Are you looking for the earliest row within each fifteen-minute division of the clock?

with data as (
    select *,
        row_number() over (partition by dateadd(second, -1 * (
                               /* how many seconds into 15-minute window */
                               60 * datepart(minute, SamplingTime) % 15
                                  + datepart(second, SamplingTime)
                               ), SamplingTime)
                           order by SamplingTime
        ) as rn
    from T
)
select * from data where rn = 1;