[email protected] table mimics inserted virtual table from AFTER INSERT triggers on [dbo].[myOrder] table
DECLARE @inserted TABLE
(
[Account] [float] NOT NULL,
[Item] [float] NOT NULL,
[Quantity] [float] NOT NULL
);
INSERT @inserted
VALUES (12345, 1, 50);
WITH CteRowNumber
AS
(
SELECT inv.ID
,inv.Account
,inv.Item
,inv.Quantity
,inv.QuantitySold
,i.Quantity QuantityOrdered
,ROW_NUMBER() OVER(PARTITION BY inv.Account,inv.Item ORDER BY inv.ID ASC) RowNumber
FROM myInventory inv
INNER JOIN @inserted i ON inv.Account = i.Account
AND inv.Item = i.Item
WHERE inv.Quantity > inv.QuantitySold
), CteRecursive
AS
(
SELECT a.ID
,a.Account
,a.Item
,a.RowNumber
,CASE
WHEN a.Quantity - a.QuantitySold < a.QuantityOrdered THEN a.Quantity - a.QuantitySold
ELSE a.QuantityOrdered
END QuantitySoldNew
,CASE
WHEN a.Quantity - a.QuantitySold < a.QuantityOrdered THEN a.Quantity - a.QuantitySold
ELSE a.QuantityOrdered
END RunningTotal
FROM CteRowNumber a
WHERE a.RowNumber = 1
UNION ALL
SELECT crt.ID
,crt.Account
,crt.Item
,crt.RowNumber
,CASE
WHEN prev.RunningTotal + (crt.Quantity - crt.QuantitySold) < crt.QuantityOrdered THEN crt.Quantity - crt.QuantitySold
ELSE crt.QuantityOrdered - prev.RunningTotal
END QuantitySoldNew
,CASE
WHEN prev.RunningTotal + (crt.Quantity - crt.QuantitySold) < crt.QuantityOrdered THEN prev.RunningTotal + (crt.Quantity - crt.QuantitySold)
ELSE crt.QuantityOrdered
END RunningTotal
FROM CteRecursive prev
INNER JOIN CteRowNumber crt ON prev.Account = crt.Account
AND prev.Item = crt.Item
AND prev.RowNumber + 1 = crt.RowNumber
WHERE prev.RunningTotal < crt.QuantityOrdered
)
SELECT cte.ID
,cte.Account
,cte.Item
,cte.QuantitySoldNew
FROM CteRecursive cte;
--or CteRecursive can be used to update QuantitySold column from [dbo].[myInventory] table
--UPDATE myInventory
--SET QuantitySold = inv.QuantitySold + cte.QuantitySoldNew
--FROM myInventory inv
--INNER JOIN CteRecursive cte ON inv.ID = cte.ID;