T-SQL - Minutes per hour between two datetimes - sql-server

Question

I have to following data:
| tid | startdate | enddate |
| 1 | 2016-12-26 12:30 | 2016-12-26 15:30 |
| 2 | 2016-12-26 13:15 | 2016-12-26 15:15 |
I would like to create a result with the hour number and then the amount of minutes the date time falls within that hour.
Example result:
| tid | hour | minutes_in |
| 1 | 12 | 30 |
| 1 | 13 | 60 |
| 1 | 14 | 60 |
| 1 | 15 | 30 |
| 2 | 13 | 45 |
| 2 | 14 | 60 |
| 2 | 15 | 15 |
Any suggestions?

Answer 1

First You need a numbers table to get your hours from 0 - 23, which can be fairly easily created on the fly with a table value constructor:
SELECT N
FROM (VALUES
(0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12),
(13),(14),(15),(16),(17),(18),(19),(20),(21),(22),(23)
) n (N);
Then you can join this to your original data to split rows out into the number required. Then you just need a case expression to apply the correct logic for calculating the minutes:
WITH Numbers (Number) AS
( SELECT N
FROM (VALUES
(0),(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12),
(13),(14),(15),(16),(17),(18),(19),(20),(21),(22),(23)
) n (N)
), SampleData (tid, StartDate, EndDate) AS
( SELECT tid, CONVERT(DATETIME2, StartDate), CONVERT(DATETIME2, EndDate)
FROM (VALUES
(1, '2016-12-26 12:30', '2016-12-26 15:30'),
(2, '2016-12-26 13:15', '2016-12-26 15:15')
) d (tid, StartDate, EndDate)
)
SELECT d.tid,
[Hour] = n.Number,
Minutes_in = CASE
-- SPECIAL CASE: START HOUR = END HOUR
WHEN DATEPART(HOUR, d.StartDate) = DATEPART(HOUR, d.EndDate)
THEN DATEDIFF(MINUTE, d.StartDate, d.EndDate)
-- FULL HOURS IN BETWEEN START AND END
WHEN n.Number > DATEPART(HOUR, d.StartDate)
AND n.Number < DATEPART(HOUR, d.EndDate) THEN 60
-- START HOUR
WHEN n.Number = DATEPART(HOUR, d.StartDate)
THEN 60 - DATEPART(MINUTE, d.StartDate)
-- END HOUR
WHEN n.Number = DATEPART(HOUR, d.EndDate)
THEN DATEPART(MINUTE, d.EndDate)
END
FROM SampleData d
INNER JOIN Numbers n
ON n.Number >= DATEPART(HOUR, d.StartDate)
AND n.Number <= DATEPART(HOUR, d.EndDate);
ADDENDUM
If you need to span days, then you could alter the logic slightly, generate a larger set of numbers to cover more hours difference, then rather than joining on the hour of the day, join the numbers on the hours difference from the start datetime to the end datetime:
SELECT *
FROM SampleData d
INNER JOIN Numbers n
ON n.Number <= DATEDIFF(HOUR, d.StartDate, d.EndDate)
This means where the range crosses over days, then there is no issue, the hours just keep incrementing. e.g.
WITH Numbers (Number) AS
( SELECT ROW_NUMBER() OVER(ORDER BY N1.N) - 1
FROM (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N1(N)
CROSS JOIN (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N2 (N)
CROSS JOIN (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N3 (N)
CROSS JOIN (VALUES (1),(1),(1),(1),(1),(1),(1),(1),(1),(1)) N4 (N)
), SampleData (tid, StartDate, EndDate) AS
( SELECT tid, CONVERT(DATETIME2, StartDate), CONVERT(DATETIME2, EndDate)
FROM (VALUES
(1, '2016-12-26 12:30', '2016-12-26 15:30'),
(2, '2016-12-26 13:15', '2016-12-26 15:15'),
(3, '2016-12-26 13:15', '2016-12-27 15:15')
) d (tid, StartDate, EndDate)
)
SELECT d.tid,
[Date] = CONVERT(DATE, d.StartDate),
[Hour] = CONVERT(TIME(0), DATEADD(HOUR, DATEPART(HOUR, d.StartDate) + n.Number, 0)),
Minutes_in = CASE
-- SPECIAL CASE: START HOUR = END HOUR
WHEN DATEPART(HOUR, d.StartDate) = DATEPART(HOUR, d.EndDate)
AND DATEDIFF(DAY, d.StartDate, d.EndDate) = 0
THEN DATEDIFF(MINUTE, d.StartDate, d.EndDate)
-- START HOUR
WHEN n.Number = 0
THEN 60 - DATEPART(MINUTE, d.StartDate)
-- END HOUR
WHEN n.Number = DATEDIFF(HOUR, d.StartDate, d.EndDate)
THEN DATEPART(MINUTE, d.EndDate)
-- FULL HOURS IN BETWEEN START AND END
ELSE 60
END
FROM SampleData d
INNER JOIN Numbers n
ON n.Number <= DATEDIFF(HOUR, d.StartDate, d.EndDate)
ORDER BY d.tid, n.Number;

Answer 2

Method -I
You can achieve this with a UDF (Another Simplest Way)
Lets build schema of your provided data
CREATE TABLE #TAB ( TID INT, STARTDATE DATETIME, ENDDATE DATETIME)
INSERT INTO #TAB
SELECT 1,'2016-12-26 12:30','2016-12-26 15:30'
UNION ALL
SELECT 2,'2016-12-26 13:15','2016-12-26 15:15'
Create one UDF to generate values between from and To
ALTER FUNCTION [dbo].[FN_GENERATE] (#FROM_NBR INT, #TO_NBR INT)
RETURNS
#RESULT TABLE(HR INT)
AS
BEGIN
;WITH CTE AS
(
SELECT #FROM_NBR AS FROM_NBR,#TO_NBR AS TO_NBR
UNION ALL
SELECT FROM_NBR+1 ,TO_NBR FROM CTE WHERE FROM_NBR<TO_NBR
)
INSERT INTO #RESULT
SELECT FROM_NBR FROM CTE
RETURN
END
Now query for data by calling the function.
;WITH CTE AS (
SELECT TID,STARTDATE,ENDDATE,DATEPART(HH,STARTDATE) FROM_HR , DATEPART(HH,ENDDATE) TO_HR FROM #TAB T
)
SELECT C1.TID,F.HR, COALESCE(DATEPART(MINUTE,FRM_HR_MINUTS.STARTDATE),DATEPART(MINUTE,TO_HR_MINUTS.ENDDATE),60 )
FROM CTE C1
CROSS APPLY
(
SELECT * FROM DBO.[FN_GENERATE] (C1.FROM_HR, C1.TO_HR)
)AS F
LEFT JOIN CTE FRM_HR_MINUTS ON C1.TID= FRM_HR_MINUTS.TID AND DATEPART(HH,FRM_HR_MINUTS.STARTDATE)= F.HR
LEFT JOIN CTE TO_HR_MINUTS ON C1.TID= TO_HR_MINUTS.TID AND DATEPART(HH,TO_HR_MINUTS.ENDDATE)= F.HR
Edit :
Method - II
Without using UDF & using MASTER.DBO.SPT_VALUES
;WITH CTE AS (
--PREPARING START HR, END HR, START_MIN, END_MIN FROM #TAB
SELECT TID,STARTDATE,ENDDATE
,DATEPART(HH,STARTDATE) FROM_HR
, DATEPART(HH,ENDDATE) TO_HR
, DATEPART(MINUTE, STARTDATE) AS STARTMIN
, DATEPART(MINUTE, ENDDATE) ENDMIN
FROM #TAB T
)
SELECT TID
, NUMBER AS HRS
--if Outer APply produce Null Display Minutes from CTE else 60 Mins
, CASE ISNULL(OA.FRM_MINS, C1.STARTMIN) + ISNULL(TO_MINS,C1.ENDMIN)
WHEN 0
THEN 60
ELSE ISNULL(OA.FRM_MINS, C1.STARTMIN) + ISNULL(TO_MINS,C1.ENDMIN)
END AS MINS
FROM CTE C1
OUTER APPLY --JOINING NUMBERS BETWEEN FROM_HR & TO_HR using MASTER.DBO.SPT_VALUES
(
SELECT NUMBER
--IF FROM_HR matched NULL Else 0
, CASE C1.FROM_HR WHEN NUMBER THEN NULL ELSE 0 END AS FRM_MINS
--IF TO_HR matched NULL Else 0
,CASE C1.TO_HR WHEN NUMBER THEN NULL ELSE 0 END AS TO_MINS
FROM MASTER.DBO.SPT_VALUES
WHERE [type]='P' AND number>0 AND number BETWEEN FROM_HR AND TO_HR
)AS OA