I have a table with, for example this data:
ID |start_date |end_date |amount
---|------------|-----------|--------
1 |2019-03-21 |2019-05-09 |10000.00
2 |2019-04-02 |2019-04-10 |30000.00
3 |2018-11-01 |2019-01-08 |20000.00
I would like te get the splitted records back with the correct calculated amount based on the year/month.
I expect the outcome to be like this:
ID |month |year |amount
---|------|-------|--------
1 |3 | 2019 | 2200.00
1 |4 | 2019 | 6000.00
1 |5 | 2019 | 1800.00
2 |4 | 2019 |30000.00
3 |11 | 2018 | 8695.65
3 |12 | 2018 | 8985.51
3 |1 | 2019 | 2318.84
What would be the best way to achieve this? I think you would have to use DATEDIFF to get the number of days between the start_date and end_date to calculate the amount per day, but I'm not sure how to return it as records per month/year.
Tnx in advance!
This is one idea. I use a Tally to create a day for every day the amount is relevant for for that ID. Then, I aggregate the value of the Amount divided by the numbers of days, which is grouped by Month and year:
CREATE TABLE dbo.YourTable(ID int,
StartDate date,
EndDate date,
Amount decimal(12,2));
GO
INSERT INTO dbo.YourTable (ID,
StartDate,
EndDate,
Amount)
VALUES(1,'2019-03-21','2019-05-09',10000.00),
(2,'2019-04-02','2019-04-10',30000.00),
(3,'2018-11-01','2019-01-08',20000.00);
GO
--Create a tally
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT TOP (SELECT MAX(DATEDIFF(DAY, t.StartDate, t.EndDate)+1) FROM dbo.YourTable t) --Limits the rows, might be needed in a large dataset, might not be, remove as required
ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1, N N2, N N3), --1000 days, is that enough?
--Create the dates
Dates AS(
SELECT YT.ID,
DATEADD(DAY, T.I, YT.StartDate) AS [Date],
YT.Amount,
COUNT(T.I) OVER (PARTITION BY YT.ID) AS [Days]
FROM Tally T
JOIN dbo.YourTable YT ON T.I <= DATEDIFF(DAY, YT.StartDate, YT.EndDate))
--And now aggregate
SELECT D.ID,
DATEPART(MONTH,D.[Date]) AS [Month],
DATEPART(YEAR,D.[Date]) AS [Year],
CONVERT(decimal(12,2),SUM(D.Amount / D.[Days])) AS Amount
FROM Dates D
GROUP BY D.ID,
DATEPART(MONTH,D.[Date]),
DATEPART(YEAR,D.[Date])
ORDER BY D.ID,
[Year],
[Month];
GO
DROP TABLE dbo.YourTable;
GO