LISTING 6: Query That Uses Solution 1's UDF and Views
SELECT
  starttime,
  endtime,
  dbo.fn_fmtelapsed(DATEDIFF(second, starttime, endtime)) AS elapsed,
  MAX(NOx) AS max_NOx
FROM VStartEnd
  JOIN Samples
    ON sample_ts BETWEEN starttime AND endtime
GROUP BY starttime, endtime