实现分类汇总的一个例子。 USE Northwind SELECT OrdD.ProductID AS ProdID, SUM(OrdD.Quantity) AS AmountSold FROM [Order Details] AS OrdD JOIN Products as Prd ON OrdD.ProductID = Prd.ProductID AND Prd.CategoryID = 2 GROUP BY OrdD.ProductID
GROUP by分组,如按班级分组统计分数,然后给班级排名: SELECT A.总分,A.班级 FROM (SELECT 班级,SUM(分数) AS 总分 FROM TABLE1 GROUP BY 班级) AS A ORDER BY A.总分 DESC
USE Northwind
SELECT OrdD.ProductID AS ProdID,
SUM(OrdD.Quantity) AS AmountSold
FROM [Order Details] AS OrdD JOIN Products as Prd
ON OrdD.ProductID = Prd.ProductID
AND Prd.CategoryID = 2
GROUP BY OrdD.ProductID
SELECT A.总分,A.班级 FROM
(SELECT 班级,SUM(分数) AS 总分 FROM TABLE1 GROUP BY 班级) AS A
ORDER BY A.总分 DESC