ALTER PROCEDURE [dbo].[AmazonInventory_s] 
@ProductID NVARCHAR(50)
AS

SELECT @ProductID = ISNULL(NULLIF(p.ShadowOf, ''), p.ID)
FROM bvc_Product p
WHERE p.ID = @ProductiD

SELECT (IsNull(Sum(pw.InventoryAvailableQty), 0)) AS Qty
FROM dbo.ProductWarehouse pw
INNER JOIN dbo.Warehouse w ON pw.WarehouseID = w.ID
INNER JOIN dbo.bvc_Product p ON pw.ProductID = p.ID
WHERE p.ID = @ProductID
	OR p.ShadowOf = @ProductID
	AND w.WarehouseType = 0 -- Default warehouse type