Cancelled amount and a corresponding entry - Postgres - postgresql

Question

I have the payment table:
There could be erroneous entries when a payment was made by mistake - see row 5 and then, this payment gets cancelled out - see row 6. I cannot figure out the query where I don't only cancel the negative amounts but also the corresponding pair. Here is the desired outcome:
You could also see the cases when several wrong payments were made and then, I need to cancel out all payments which if summed up give the cancelled amount.
The desired outcome:
I found Remove Rows That Sum Zero For A Given Key, Selecting positive aggregate value and ignoring negative in Postgres SQL and https://www.sqlservercentral.com/forums/topic/select-all-negative-values-that-have-a-positive-value but it is not exactly what I need
I already don't mind cases like case 2. At least, find a reliable way to exclude those like 5;-5.

Answer 1

you can try this for deleting the rows from the table :
WITH RECURSIVE cancel_list (id, total_cancel, sum_cancel, index_to_cancel) AS
( SELECT p.id, abs(p.amount), 0, array[p.index]
FROM payment_table AS p
WHERE p.amount < 0
AND p.id = id_to_check_and_cancel -- this condition can be suppressed in order to go through the full table payment
UNION ALL
SELECT DISTINCT ON (l.id) l.id, l.total_cancel, l.sum_cancel + p.amount, l.index_to_cancel || p.index
FROM cancel_list AS l
INNER JOIN payment_table AS p
ON p.id = l.id
WHERE l.sum_cancel + p.amount <= l.total_cancel
AND NOT l.index_to_cancel #> array[p.index] -- this condition is to avoid loops
)
DELETE FROM payment_table AS p
USING (SELECT DISTINCT ON (c.id) c.id, unnest(c.index_to_cancel) AS index_to_cancel
FROM cancel_list AS c
ORDER BY c.id, array_length(c.index_to_cancel, 1) DESC
) AS c
WHERE p.index = c.index_to_cancel;
you can try this for just querying the table without the hidden rows :
WITH RECURSIVE cancel_list (id, total_cancel, sum_cancel, index_to_cancel) AS
( SELECT p.id, abs(p.amount), 0, array[p.index]
FROM payment_table AS p
WHERE p.amount < 0
AND p.id = id_to_check_and_cancel -- this condition can be suppressed in order to go through the full table payment
UNION ALL
SELECT DISTINCT ON (l.id) l.id, l.total_cancel, l.sum_cancel + p.amount, l.index_to_cancel || p.index
FROM cancel_list AS l
INNER JOIN payment_table AS p
ON p.id = l.id
WHERE l.sum_cancel + p.amount <= l.total_cancel
AND NOT l.index_to_cancel #> array[p.index] -- this condition is to avoid loops
)
SELECT *
FROM payment_table AS p
LEFT JOIN (SELECT DISTINCT ON (c.id) c.id, c.index_to_cancel
FROM cancel_list AS c
ORDER BY c.id, array_length(c.index_to_cancel, 1) DESC
) AS c
ON c.index_to_cancel #> array[p.index]
WHERE c.index_to_cancel IS NULL ;