How to loop in Select Query SQL - sql

Question

Hi I have this Table like this
ICN StartContract EndContract ContractValue PeriodOfContract
A 2019-12-31 17:00:00.000 2020-03-30 17:00:00.000 19546194.00 3.00
B 2019-12-31 17:00:00.000 2020-12-30 17:00:00.000 1397095800.00 12.00
C 2021-02-28 17:00:00.000 2022-02-27 17:00:00.000 4016244584.00 12.00
D 2018-05-27 17:00:00.000 2021-05-30 17:00:00.000 9686992857.00 36.00
I want to create a view to loop a Period of Contract and create a new row in My View. Example Result
ICN Date Amount
A 2019-12-31 6,515,398
A 2020-01-31 6,515,398
A 2020-02-29 6,515,398
I've seen some loop examples but mostly it's used only on the function. I want to loop the period of the contract and populate a new row based on the period on my View.
This is My Query
/****** Script for SelectTopNRows command from SSMS ******/
SELECT
ICN, StartContract , EndContract, ContractValue, PeriodOfContract
FROM [FactProject]
Any suggestion or example query to do that? Thanks

Answer 1

;WITH n(n) AS
(
SELECT 0
UNION ALL
SELECT n+1 FROM n WHERE n+1 < 100
)
SELECT ICN, C.[Date], C.Amount FROM T
CROSS APPLY
(
SELECT
CAST(DATEADD(MONTH, n, StartContract) AS date) [Date],
CAST(ROUND(ContractValue / PeriodOfContract, 0) AS int) Amount
FROM n
WHERE
n.n < T.PeriodOfContract
) C
ORDER BY ICN, [Date]
I used WITH n(n) to generate a list of int numbers (explained here). Note: You should increase the number 100 if you may have a PeriodOfContract value more than 100.
Output:
ICN Date Amount
A 2019-12-31 6515398
A 2020-01-31 6515398
A 2020-02-29 6515398
B 2019-12-31 116424650
B 2020-01-31 116424650
...