How to obtain Additions and Deductions from table - sql-server

Question

I have this table where I am storing the Sale Orders. The scenario is that once any sale order is punched it is not finalized, and requires editing later on so if any more items are added and saved again the sale order is updated with transaction number more than the previous one to keep the track of the changes. Here is a sample data that a sale order was punched and then 2 times more items were added and amount was changed and in the last row as shown items were cancelled and amount was changed.
I want to calculate the amount of the additions made in the sale order every time new items were added and the cancellations as well that how much worth of items were cancelled.
CREATE TABLE SaleOrder
(
TransactionNo Int,
SaleOrderDate DATE,
Code VARCHAR(25),
Quantity INT,
TotalAmount Numeric(18,2),
Remarks VARCHAR(25)
)
INSERT INTO SaleOrder VALUES (NULL, '2018-10-01', 'SO-001-OCT-18', 6, '2500', 'Hello');
INSERT INTO SaleOrder VALUES (1, '2018-10-01', 'SO-001-OCT-18', 8, '2600', 'Hello');
INSERT INTO SaleOrder VALUES (2, '2018-10-01', 'SO-001-OCT-18', 12, '3400', 'Hello');
INSERT INTO SaleOrder VALUES (3, '2018-10-01', 'SO-001-OCT-18', 9, '2900', 'Hello');
This will be the result that I am expected.
Code SaleOrderDate Quantity InitialAmount Addition Cancellation
SO-001-OCT-18 2018-10-01 9 2500.00 900.00 500.00
I have written this query but it's not helping that much.
;WITH CTE AS (
SELECT
[TransactionNo], [Code], [SaleOrderDate], [Quantity], [TotalAmount],
CAST('Oct 1 2018 10:16AM' AS DATE) AS [DateFrom], CAST('Oct 4 2018 10:16AM' AS DATE) AS [DateTo]
FROM [SaleOrder]
GROUP BY
[TransactionNo], [Code], [SaleOrderDate], [TotalAmount], Quantity
)
SELECT
[D].[TransactionNo], [D].[Code], [D].[SaleOrderDate], [D].[Quantity], [D].TotalAmount,
--CAST('Oct 4 2018 4:06PM' AS DATE) AS [DateFrom],
--CAST('Oct 4 2018 4:06PM' AS DATE) AS [DateTo],
[D].[Balance], [D].[Balance]-ISNULL(NULLIF([D].TotalAmount, 0),0) [Opening]
FROM(
SELECT *,
SUM(TotalAmount) OVER (PARTITION BY [Code] ORDER BY [TransactionNo], [SaleOrderDate]) AS [Balance]
FROM CTE
)D
WHERE [SaleOrderDate] BETWEEN CAST('Oct 1 2018 10:16AM' AS DATE) AND CAST('Oct 4 2018 10:16AM' AS DATE)
ORDER BY [SaleOrderDate]

Answer 1

use the LAG() window function to get previous value and compare to determine it is an addition or cancellation.
; WITH cte as
(
SELECT *,
row_no = ROW_NUMBER() OVER (PARTITION BY Code ORDER BY TransactionNo DESC),
Addition = CASE WHEN TotalAmount > LAG(TotalAmount) OVER (PARTITION BY Code ORDER BY TransactionNo)
THEN TotalAmount - LAG(TotalAmount) OVER (PARTITION BY Code ORDER BY TransactionNo)
ELSE 0
END,
Cancellation = CASE WHEN TotalAmount < LAG(TotalAmount) OVER (PARTITION BY Code ORDER BY TransactionNo)
THEN LAG(TotalAmount) OVER (PARTITION BY Code ORDER BY TransactionNo) - TotalAmount
ELSE 0
END
FROM SaleOrder
)
SELECT Code,
SaleOrderDate,
Quantity = MAX (CASE WHEN row_no = 1 then Quantity END),
InitialAmount = MAX (CASE WHEN TransactionNo IS NULL THEN TotalAmount END),
Addition = SUM (Addition),
Cancellation = SUM (Cancellation)
FROM cte
GROUP BY Code, SaleOrderDate

Answer 2

Are you trying to do this? :
SELECT
Code
, MAX(SaleOrderDate) SaleOrderDate
, MAX(Quantity) Quantity
, MAX(InitialAmount) InitialAmount
, SUM(Addition) Addition
, ABS(SUM(Cancellation)) Cancellation
FROM (
SELECT
Code
, CASE WHEN rn = cnt THEN SaleOrderDate END SaleOrderDate
, CASE WHEN rn = cnt THEN Quantity END Quantity
, InitialAmount
, CASE WHEN Diff > 0 THEN Diff ELSE 0 END Addition
, CASE WHEN Diff < 0 THEN Diff ELSE 0 END Cancellation
FROM (
SELECT *
, CASE WHEN TransactionNo IS NULL THEN TotalAmount END InitialAmount
, LEAD(TotalAmount) OVER(PARTITION BY Code ORDER BY TransactionNo) nxtPrice
, LEAD(TotalAmount) OVER(PARTITION BY Code ORDER BY TransactionNo) - TotalAmount Diff
, COUNT(*) OVER(PARTITION BY Code) cnt
, ROW_NUMBER() OVER(PARTITION BY Code ORDER BY SaleOrderDate) rn
FROM SaleOrder
) D
) C
GROUP BY
Code