SQL Server 2019

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Microsoft SQL Server 2019 (RTM-CU16) (KB5011644) - 15.0.4223.1 (X64) Apr 11 2022 16:24:07 Copyright (C) 2019 Microsoft Corporation Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)

CREATE TABLE [dbo].[loan](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [Starting_Date] [date] NULL,
    [Loan_Term] [int] NULL,
    [Monthly_Payment] [decimal](19, 2) NULL
) ON [PRIMARY]

INSERT INTO [dbo].[loan]
    ([Starting_Date]
    ,[Loan_Term]
    ,[Monthly_Payment])
VALUES
    ('8/1/2020', 52, 1),
    ('6/2/2010', 64, 2500),
    ('9/11/2011', 66, 650),
    ('7/4/2011', 36, 600),
    ('11/19/2014', 36, 450),
    ('4/21/2017', 24, 650),
    ('6/25/2009', 68, 7500),
    ('4/3/2016', 72, 12000),	--12000
    ('5/2/2013', 12, 330),
    ('7/11/2011', 32, 331.33),
    ('6/11/2013', 36, 200),
    ('7/11/2014', 34, 250),
    ('8/15/2015', 32, 673),
    ('9/15/2017', 31, 8),		--8
    ('11/6/2019', 64, 65),	
    ('10/13/2017', 52, 128)	--128

--SELECT * FROM dbo.loan l
--ORDER BY id, starting_date

;WITH loanCTE as 
(
-- Anchor Member
SELECT monthly_payment, DATEADD(MM, loan_term, starting_date) as loan_end_date, starting_date, starting_date as current_month
    FROM loan
UNION ALL
-- Recursive Member
SELECT monthly_payment, loan_end_date, starting_date, DATEADD(MM, 1, current_month)
    FROM loanCTE
    WHERE current_month < loan_end_date -- Terminating condition
)
,
temp as
(
	SELECT  YEAR(current_month) as [Year], MONTH(current_month) as [Month],  SUM(monthly_payment) as total_montly_payments
	FROM loanCTE
	GROUP BY YEAR(current_month), MONTH(current_month) 
)

SELECT *
FROM temp
WHERE datefromparts(YEAR, MONTH, 1) BETWEEN GETDATE()-395 AND GETDATE()  --395 to include 201908
ORDER BY [Year] DESC, [Month] DESC

Year	Month	total_montly_payments
2024	5	66.00
2024	4	66.00
2024	3	66.00
2024	2	66.00
2024	1	66.00
2023	12	66.00
2023	11	66.00
2023	10	66.00
2023	9	66.00
2023	8	66.00
2023	7	66.00
2023	6	66.00
2023	5	66.00