Loop through invoices from the bottom up untill transaction amount is reached - sql-server

Question

What I've thought up in my mind I can't find any helpful resources for online. I have a table that has a transaction amount per client. This amount is either zero or below zero. In another table I have invoices with total amounts per invoice per client. For all the transaction records that are below zero I want to calculate which invoices are still (partial) open.
Imagine client A has a transaction amount of -300 and client B has a transaction amount of -100. So there is a table with the fields client_id and transaction_amount. Then take a look at the Excel image below.
client
invoice
amount
aggregated amount from last invoice up
status
A
invoice 101
-25
-575
closed
A
invoice 102
-100
-550
closed
A
invoice 103
-100
-450
closed
A
invoice 104
-75
-350
partial open
A
invoice 105
-25
-275
fully open
A
invoice 106
-150
-250
fully open
A
invoice 107
-25
-100
fully open
A
invoice 108
-75
-75
fully open
B
invoice 201
-25
-125
closed
B
invoice 202
-50
-100
fully open
B
invoice 203
-25
-50
fully open
B
invoice 204
-25
-25
fully open
So when starting the calculation for client A at invoice 8 and working my way up by aggregating the amounts I see that invoices 5 through 8 are fully open and invoice 4 is partially open. For client B invoces 4 through 2 are open. I then want a query result that shows me those invoices for client A and B. Just so you know, the real dataset has lots of clients and lots of invoices.
In an extended version of what I would like to see you do not only see that invoice 4 is partially pasi, but you also see that an amount of 25 was paid, but 50 remains.
I think I need to have a reversed kind of loop? I've tried a few things by having an #transaction variable and subtracting the amounts, but it either keeps on running or returns the same invoice number over and over again. The result should be something like the image below.
client
invoice
amount
amount open in transaction "debt amount"
A
invoice 104
-75
-25 (-50 isn't in the transaction "debt amount": -75 + -25 + -150 + -25 + -25 = -300. That's why it's a partial in the status field.)
A
invoice 105
-25
-25
A
invoice 106
-150
-150
A
invoice 107
-25
-25
A
invoice 108
-75
-75
B
invoice 202
-50
-50
B
invoice 203
-25
-25
B
invoice 204
-25
-25
I can't imagine that I'm the first to want to do this, so if anyone has a link to documentation on how to do this or is able to help me in this topic, it would be much appreciated.

Answer 1

Answer provided by SOS with some help from shawnt00. Thanks. See the dbfiddle result for the code.
WITH cte AS (
SELECT client
, invoice
, amount
, status
, [debt amount]
, SUM(Amount) OVER(PARTITION BY client ORDER BY invoice DESC) AS [aggregated amount from last invoice up]
, SUM(Amount) OVER(PARTITION BY client ORDER BY invoice DESC)
+ ABS([debt amount]) AS RemainingDebt
FROM YourTable
)
SELECT client
, invoice
, amount
, [aggregated amount from last invoice up]
, CASE WHEN RemainingDebt >= 0 THEN 'fully open'
WHEN ABS(RemainingDebt) < ABS(Amount) THEN 'partial open'
WHEN ABS(RemainingDebt) >= ABS(Amount) THEN 'closed'
END AS status
FROM cte
ORDER BY client, invoice
Results:
client
invoice
amount
aggregated amount from last invoice up
status
A
invoice 101
-25
-575
closed
A
invoice 102
-100
-550
closed
A
invoice 103
-100
-450
closed
A
invoice 104
-75
-350
partial open
A
invoice 105
-25
-275
fully open
A
invoice 106
-150
-250
fully open
A
invoice 107
-25
-100
fully open
A
invoice 108
-75
-75
fully open
B
invoice 201
-25
-125
closed
B
invoice 202
-50
-100
fully open
B
invoice 203
-25
-50
fully open
B
invoice 204
-25
-25
fully open
db<>fiddle here