Reporting on time information using start and end time - sql

Question

Is it possible to create a report that sums hours for a day grouped by an Id using a start and end time stamp?
I need to be able to split time that spans days and take part of that time and sum to the correct date group.
NOTE: The date ids are to a date dimension table.
------------------------------------------------------------------------------
TaskId | StartDateId | EndDateId | StartTime | EndTime
------------------------------------------------------------------------------
2 | 20190317 | 20190318 | 2019-03-17 16:30:00 | 2019-03-18 09:00:00
------------------------------------------------------------------------------
1 | 20190318 | 20190318 | 2019-03-18 09:00:00 | 2019-03-18 16:30:00
------------------------------------------------------------------------------
2 | 20190318 | 20190319 | 2019-03-18 16:30:00 | 2019-03-19 09:00:00
------------------------------------------------------------------------------
So based on this, the desired report output would be:
-------------------------
Date | Task | Hours
-------------------------
2019-03-17 | 2 | 7.5
-------------------------
2019-03-18 | 1 | 7.5
-------------------------
2019-03-18 | 2 | 16.5
-------------------------
...
The only working solution I have managed to implement is splitting records so that no record spans multiple days. I was hoping to find a report query solution, rather than an ETL base based solution.

Answer 1

I have tried to simulate your problem here: https://rextester.com/DEV45608 and I hope it helps you :) (The CTE GetDates can be replaced by your date dimension)
DECLARE #minDate DATE
DECLARE #maxDate DATE
CREATE TABLE Tasktime
(
Task_id INT,
Start_time DATETIME,
End_time DATETIME
);
INSERT INTO Tasktime VALUES
(2,'2019-03-17 16:30:00','2019-03-18 09:00:00'),
(1,'2019-03-18 09:00:00','2019-03-18 16:30:00'),
(2,'2019-03-18 16:30:00','2019-03-19 09:00:00');
SELECT #mindate = MIN(Start_time) FROM Tasktime;
SELECT #maxdate = MAX(End_time) FROM Tasktime;
;WITH GetDates AS
(
SELECT 1 AS counter, #minDate as Date
UNION ALL
SELECT counter + 1, DATEADD(day,counter,#minDate)
from GetDates
WHERE DATEADD(day, counter, #minDate) <= #maxDate
)
SELECT counter, Date INTO #tmp FROM GetDates;
SELECT
g.Date,
t.Task_id,
SUM(
CASE WHEN CAST(t.Start_time AS DATE) = CAST(t.End_time AS DATE) THEN
DATEDIFF(second, t.Start_time, t.End_time) / 3600.0
WHEN CAST(t.Start_time AS DATE) = g.Date THEN
DATEDIFF(second, t.Start_time, CAST(DATEADD(day,1,g.Date) AS DATETIME)) / 3600.0
WHEN CAST(t.End_time AS DATE) = g.Date THEN
DATEDIFF(second, CAST(g.Date AS DATETIME), t.End_time) / 3600.0
ELSE
24.0
END) AS hours_on_the_day_for_the_task
from
#tmp g
INNER JOIN
Tasktime t
ON
g.Date BETWEEN CAST(t.Start_time AS DATE) AND CAST(t.End_time AS DATE)
GROUP BY g.Date, t.Task_id

Answer 2

The Desired Date can be joined to the date dimension and return the "calendar date" and you can show that date in the report.
As for the HOURS.. when you are retrieving your dataset in SQL, just do this.. it is as simple as:
cast(datediff(MINUTE,'2019-03-18 16:30:00','2019-03-19 09:00:00') /60.0 as decimal(13,1)) as 'Hours'
So in your case it would be
cast(datediff(MINUTE,sometable.startdate,sometable.enddate) /60.0 as decimal(13,1)) as 'Hours'
Just doing a HOUR will return the whole hour.. and dividing by 60 will return a whole number. Hence the /60.0 and the cast