Group by Time Interval

Question

I need to Group my Table into 15 minutes Intervals. I can do that with:

select dateadd(minute, datediff(minute, 0, ts) / 15 * 15, 0), sum (goodpieces) 
from Stat         


        

Answer 1

Create a table with every possible timestamp in 15 minute increments, and do a LEFT JOIN from it to your query above.

SELECT * FROM timestamps LEFT JOIN (SELECT dateadd......) ON timestamps.timestamp = StationCount.ts

If you know your chart always covers a 24 hour period, you only need to create a table with the numbers 0-95, then for each entry add it to the start time of your chart.

SELECT *
  FROM (SELECT dateadd(minute, , number*15) timestamp FROM numbers) timestamps LEFT JOIN
       (SELECT dateadd......) ON timestamps.timestamp = StationCount.ts