How do I calculate amount of time in each week between two dates - SQL Server - sql

Question

[EDITED TO SIMPLIFY]
I have 500+ records. All of which have a reference number, a start date, an end date and a total machining time.
Ref StartDate EndDate MachineTimeHours
123 24/01/2020 30/01/2020 28
321 25/02/2020 27/02/2020 18
Starting at the start date, I need to calculate how many machining hours fall into 1 week and how many fall into the next.
Our working days are Monday to Thursday 8 Hours & Friday 4 Hours.
Ref 321 has a start of 25/2 which is a Tuesday and a finish date of 27/2 which is a Thursday in the same week. This will calculate as all 18 hours being in the same week.
Ref 123 has a start of 24/01. This is a Friday in Week 4 of 2020.
Based on my rules, that would be 4 hours in week 4 and 24 Hours in week 5.
I have a table called 'DatesList' which has all days on it (as well as week number and working hours).
I need my table to list each record for each week and I'll do the grouping on a separate report.
In effect I'd like
Ref StartDate EndDate MachineTimeHours Week Hours
123 24/01/2020 30/01/2020 28 4 4
123 24/01/2020 30/01/2020 28 5 24
321 25/02/2020 27/02/2020 18 9 18

Answer 1

You can start with creating some reference tables.
For the example those are just temporary tables.
Reference data:
--
-- Reference tables
--
CREATE TABLE #ref_calendar
(
CalDate DATE PRIMARY KEY,
DayOfWeek SMALLINT NOT NULL,
WeekNr SMALLINT NOT NULL,
IsHoliday BIT NOT NULL DEFAULT 0
);
DECLARE #year int = 2020;
SET DATEFIRST 1; -- 1: monday start
;WITH RCTE_DATES AS
(
SELECT
DATEFROMPARTS(#year, 1, 1) AS caldate
UNION ALL
SELECT dateadd(day, 1, caldate)
FROM RCTE_DATES
WHERE caldate <= DATEFROMPARTS(#year, 12, 31)
)
INSERT INTO #ref_calendar (CalDate, DayOfWeek, WeekNr)
SELECT
caldate,
DATEPART(weekday, caldate) AS DayOfWeek,
DATEPART(week, caldate) AS WeekNr
FROM rcte_dates c
WHERE NOT EXISTS
(
SELECT 1
FROM #ref_calendar ref
WHERE ref.CalDate = c.caldate
)
OPTION (MAXRECURSION 366);
CREATE TABLE #ref_workhours
(
Id INT IDENTITY(1,1) PRIMARY KEY,
DayOfWeek SMALLINT NOT NULL,
WorkHours DECIMAL(4,2) NOT NULL,
ActiveFrom DATE NOT NULL DEFAULT GetDate(),
ActiveTill DATE
);
INSERT INTO #ref_workhours
(DayOfWeek, WorkHours) VALUES
(1, 8.0), (2, 8.0), (3, 8.0), (4, 8.0), (5, 4.0),
(6, 0), (7, 0);
Some sample data:
--
-- Sample data
--
CREATE TABLE YourDateRangeTable
(
Id INT IDENTITY(1,1) PRIMARY KEY,
JobNumber INT NOT NULL,
PartNumber VARCHAR(8) NOT NULL,
Machine CHAR(3) NOT NULL,
StartDate DATE NOT NULL,
EndDate DATE NOT NULL
);
INSERT INTO YourDateRangeTable
(JobNumber, PartNumber, Machine, StartDate, EndDate) values
(12345, 'XYZ321', 'DL8', '2020-01-24', '2020-01-30');
Then you can run a query that uses the reference tables.
SELECT JobNumber, PartNumber, Machine
, YEAR(cal.CalDate) AS [Year]
, cal.WeekNr AS [Week]
, SUM(w.WorkHours) AS [Hours]
FROM YourDateRangeTable t
JOIN #ref_calendar cal
ON cal.CalDate >= t.StartDate
AND cal.CalDate < t.EndDate
JOIN #ref_workhours w
ON w.DayOfWeek = cal.DayOfWeek
GROUP BY JobNumber, PartNumber, Machine
, YEAR(cal.CalDate), cal.WeekNr;
Returns:
JobNumber PartNumber Machine Year Week Hours
12345 XYZ321 DL8 2020 4 4.00
12345 XYZ321 DL8 2020 5 24.00
A test on db<>fiddle here

Answer 2

You can get all the detes of two given date and also weeknumber and a case statement for the working hour. Based on the result from the inner query write an outer query which will give the sum of total working hour.
Here is the given query.
DECLARE #MinDate DATE = '20200124',
#MaxDate DATE = '20200130'
--Fri Week 4 = 4 hours
--Mon Week 5 = 8 hours
--Tue Week 5 = 8 hours
--Wed Week 5 = 8 hours
Select WeekNo, SUM(WorkingHour) as TotalWorkingHour from(
Select [DATE], DATEPART(WEEK, [DATE]) - DATEPART(WEEK, DATEADD(MM, DATEDIFF(MM,0,[DATE]), 0))+ 1 as WeekNo,
DATENAME(weekday, [DATE]) as WeekDay, Case DATENAME(weekday, [DATE])
when 'Friday' then 4
when 'Monday' then 8
when 'Tuesday' then 8
when 'Wednesday' then 8
else 0
end as WorkingHour from(
SELECT TOP (DATEDIFF(DAY, #MinDate, #MaxDate) + 1)
Date = DATEADD(DAY, ROW_NUMBER() OVER(ORDER BY a.object_id) - 1, #MinDate)
FROM sys.all_objects a
CROSS JOIN sys.all_objects b
)a
)b group by WeekNo
It will give the result as below:
WeekNo TotalWorkingHour
------------------------
4 4
5 24
You can find the demo Here.