Count number of occurrences per hour between two dates SQL Server - sql-server

Question

I've created a temp table #MB that has a record ID (119 rows), start and end date (partial screenshot of the list is below):
I'm trying to get a count of occurrences that happened each hour for each record ID during the start and end date (or number of occurrences each hour when ID was active between two dates).
I've used this code:
SELECT *
FROM
(SELECT
ISNULL(CAST(part AS VARCHAR(5)), 'Total') AS part,
COUNT(*) AS part_count
FROM
(SELECT DATEPART([HOUR], [Start]) AS part
FROM #MB) grp
GROUP BY
GROUPING SETS((part),())
) pre
PIVOT
(MAX(part_count)
FOR part IN ([0], [1], [2], [3], [4], [5], [6], [7], [8],
[9], [10], [11], [12], [13], [14], [15], [16],
[17], [18], [19], [20], [21], [22], [23], Total)
) pvt;
but it counts only records based on the start date (don't count each hour between two dates) and I stuck on how to generate occurrences per hour for each ID between two dates that I can later use to pre-aggregate and pivot.

Answer 1

first, you need to generate the list of rows for each hour
here i am using a recursive cte query to do it
; with MB as
(
select ID, [Start], [End], [Date] = [Start]
from #MB
union all
select ID, [Start], [End], [Date] = dateadd(hour, 1, convert(date, c.[Date]))
from MB c
where dateadd(hour, 1, c.[Date]) < [End]
)
select *
from MB
so in your pivot query , just change to this
; with MB as
(
select ID, [Start], [End], [Date] = [Start]
from #MB
union all
select ID, [Start], [End], [Date] = DATEADD(HH,DATEPART(HH,[Start]),CAST(CAST([Start] AS DATE) AS DATETIME))
from MB c
where dateadd(hour, 1, c.[Date]) < [End]
)
SELECT *
FROM (
SELECT ISNULL(CAST(part AS VARCHAR(5)), 'Total') AS part,
COUNT(*) AS part_count
FROM (
SELECT DATEPART([HOUR], [Date]) AS part
FROM MB -- changed to the cte
) grp
GROUP BY
GROUPING SETS((part),())
) pre
PIVOT (MAX(part_count) FOR part IN (
[0],[1],[2],[3],[4],[5],[6],[7],[8],
[9],[10],[11],[12],[13],[14],[15],[16],
[17],[18],[19],[20],[21],[22],[23], Total)) pvt;