Comparaison de prix avec plusieurs magasins en sql

J'ai essayé de le faire même si je ne savais pas trop comment vous vouliez calculer votre colonne DifferencePercentage, donc vous voudrez peut-être regarder cela de plus près.

CREATE TABLE #tempProduct
(
    ID INT,
    SellerName VARCHAR(100),
    Total MONEY,
    Availability VARCHAR(100),
    Offer VARCHAR(100),
    Competitors INT
)

INSERT INTO #tempProduct (ID, SellerName, Total, Availability, Offer)
SELECT DISTINCT p.id, pp.SellerName, pp.Price + ISNULL(pp.Shipping,0), pp.Available, pp.Offer
FROM Products p
JOIN Product_Price pp
    ON p.id = pp.ProductId

-- Get Sears competitors
UPDATE tp
SET Competitors = pp.CompetitorCount
FROM #tempProduct tp
JOIN (
        SELECT ProductId, COUNT(sellerName) [CompetitorCount] 
        FROM Product_Price 
        WHERE SellerName <> 'Sears' AND Price + ISNULL(Shipping,0) IS NOT NULL
        GROUP BY ProductId
    ) pp
    ON pp.ProductId = tp.ID
WHERE tp.SellerName = 'Sears'

 SELECT DISTINCT 
    p.id, 
    p.ProductName,
    p.ProductCategory, 
    p.ProductImage, 
    p.ProductUri, 
    stp.Total [SearsTotal], 
    stp.Availability [SearsAvailability], 
    stp.Offer [SearsOffer], 
    stp.Competitors [#Competitors],
    100 - (((ISNULL(etp.Total,0) + ISNULL(atp.Total, 0))/stp.Competitors)/stp.Total) * 100 [DifferencePercentage(Sears & others)], -- Not sure how you want to calculate price difference
    atp.Total, 
    atp.Availability [AmazonTotal], 
    atp.Offer [AmazonOffer], 
    etp.Total [eBayTotal], 
    etp.Availability [eBayAvailability], 
    etp.Offer [eBayOffer]
 FROM Products p
JOIN Product_Price pp
    ON pp.ProductId = p.ID
JOIN #tempProduct stp
    ON stp.ID = p.id
JOIN #tempProduct etp
    ON etp.ID = p.id
JOIN #tempProduct atp
    ON atp.ID = p.id
WHERE stp.SellerName = 'Sears'  
AND etp.SellerName = 'eBay'
AND atp.SellerName = 'Amazon'