Onfly Query - cumulative sum the stock change values by articles

Hello!

Durumdara <durumdara@gmail.com> ezt írta (időpont: 2021. jan. 7., Cs,
10:17):

Hello!

I have a query where I can show the positive and negative future changes
of the articles.
For example:

select art.id, art.name, art.actual_stock, art.min_stock,
change.stock_change, change.date
from change left join art on art.id = change.art_id
order by art.id, change.id

Ok, I have a list of the changes.

I need to sum these changes to get the rows where the stock is negative or
below the minimum.

1, bla, 100, 20, +20, 2021-02-01, [120]
1, bla, 100, 20, -10, 2021-02-01, [110]
1, bla, 100, 20, -100, 2021-02-01, [10] - below minimum
1, bla, 100, 20, -20, 2021-02-01, [-10] - below zero
2, bli, 20, 10, 10, 2021-02-01, [20]
2, bli, 20, 10, -15, 2021-02-01, [5] below minimum

How do I use a window function (can I use it) to "reset" the stock in
every first record of the articles - to cumulate the data?

Or do I need to store data in a temporary table and use stored procedure
to fill up the cumulated stock value?

Sorry... I solved it!

First I need to window sum "change.stock_change" (partition by art.id),
then I need to add the starting stock value to all.
In this case I don't need to check what is the first item of the article
(where I need to add the actual stock).

Best wishes
dd