主题：[公告]关于第二次课堂发言作业

相应的数据库结构为：

此主题相关图片如下：

查询练习的答案为：

查询1：

SELECT TOP 5 SUM(OrderDetails.Quantity) as TotalNum, Products.ModelName

FROM OrderDetails INNER JOIN Products ON OrderDetails.ProductID = Products.ProductID

GROUP BY Products.ModelName

ORDER BY TotalNum DESC

查询2：

declare @ProductID int

set @ProductID=378

--Protection_Guard Dog Pacifier

SELECT TOP 5 OrderDetails.ProductID,min(Products.ModelName),SUM(OrderDetails.Quantity) as TotalNum

FROM OrderDetails INNER JOIN Products ON OrderDetails.ProductID = Products.ProductID

WHERE OrderID IN (SELECT DISTINCT OrderID FROM OrderDetails WHERE ProductID = @ProductID) AND OrderDetails.ProductID != @ProductID

GROUP BY OrderDetails.ProductID

ORDER BY TotalNum DESC