Fetch conditional rows in SQL server - sql

Question

I need a query like below. ApplicationID and InvoiceNumber columns show purchases made. Negative values in the Revenue rows indicate shopping refund. The ApplicationID column does not change when the purchase is refunded, but the InvoiceNumber column changes for the refund. I determine the returns according to the price totals of different InvoiceNumbers in the same ApplicationID equal to zero. For example, customer A bought 4 products that InvoiceNumber=AA in ApplicationID=11 shopping, but refund 2 of them (InvoiceNumber=BB). I want to get the remaining rows after the refunds are extracted. So in this example, rows 1-2 and 5-6 will eliminate each other for ApplicationID=11 and only rows 3-4 will remain. In addition, ApplicationID=22 and ApplicationID=33 rows will also come as it does not contain refunds. Finally, rows 3,4,7, 8 and 9 will get. How do I do this?
CustomerCode ApplicationID InvoiceNumber Date Revenue
A 11 AA 1.01.2020 150
A 11 AA 2.01.2020 200
A 11 AA 1.01.2020 250
A 11 AA 1.01.2020 300
A 11 BB 5.01.2020 -150
A 11 BB 5.01.2020 -200
A 22 CC 7.02.2020 500
A 22 DD 7.02.2020 700
A 11 AA 2.01.2020 800
I wrote the result I want. I want to subtract zero sum of revenue according to CustomerCode and ApplicationID and fetch all other columns
example code:
select a.CustomerCode,a.ApplicationID from Table a
group by CustomerCode,a.ApplicationID
having SUM(Revenue)>0
My desired result:
CustomerCode ApplicationID InvoiceNumber Date Revenue
A 11 AA 1.01.2020 250
A 11 AA 1.01.2020 300
A 22 CC 7.02.2020 500
A 22 DD 7.02.2020 700
A 11 AA 2.01.2020 800

Answer 1

I think you've gone down a route of needing to sum your results to remove certain rows from your data but that's not necessarily the case.
You can use a LEFT JOIN back to itself joining on CustomerCode, ApplicationID and Revenue = -Revenue; this effectively finds "purchase" rows that have an associated "refund" row (and vice versa). You can then just filter them off with your WHERE clause
Here's the code I used
DROP TABLE IF EXISTS #Orders
CREATE TABLE #Orders (CustomerCode VARCHAR(1), ApplicationID INT, InvoiceNumber VARCHAR(2), [Date] DATE, Revenue INT)
INSERT INTO #Orders (CustomerCode, ApplicationID, InvoiceNumber, Date, Revenue)
VALUES ('A', 11, 'AA', '2020-01-01', 150),
('A', 11, 'AA', '2020-01-02', 200),
('A', 11, 'AA', '2020-01-01', 250),
('A', 11, 'AA', '2020-01-01', 300),
('A', 11, 'BB', '2020-01-05', -150),
('A', 11, 'BB', '2020-01-05', -200),
('A', 22, 'CC', '2020-01-07', 500),
('A', 22, 'DD', '2020-01-07', 700),
('A', 11, 'AA', '2020-01-02', 800)
SELECT O.CustomerCode, O.ApplicationID, O.InvoiceNumber, O.Date, O.Revenue
FROM #Orders AS O
LEFT JOIN #Orders AS O2 ON O2.ApplicationID = O.ApplicationID AND O2.CustomerCode = O.CustomerCode AND O.Revenue = -O2.Revenue
WHERE O2.ApplicationID IS NULL
And this is the output:
CustomerCode ApplicationID InvoiceNumber Date Revenue
A 11 AA 2020-01-01 250
A 11 AA 2020-01-01 300
A 22 CC 2020-01-07 500
A 22 DD 2020-01-07 700
A 11 AA 2020-01-02 800