Question

写一个查询，返回从ATunes购买了最多歌曲的前五位客户的名字，按购买次数（降序）排序。我还必须将结果限制在前5位。

SELECT P.CustomerID, A.FirstName, A.LastName, P.DateOfPurchase, COUNT(DateOfPurchase) as NumberOfPurchases
ORDER BY NumberOfPurchases DESC, LIMIT 0,5
FROM Purchases as P
JOIN ATunesCostumers as A on (A.CustomerID = P.CustomerID)
GROUP BY CustomerID;

这是我正在尝试的，我收到语法错误。当我摆脱ORDER BY和LIMIT语句时，我得到了我需要的一切，除了限制和正确的排序。我很茫然，有谁知道我做错了什么？

Answer 1

试试这个：

SELECT P.CustomerID, A.FirstName, A.LastName, P.DateOfPurchase, COUNT(DateOfPurchase) as NumberOfPurchases
FROM Purchases as P
JOIN ATunesCostumers as A on P.CustomerID = A.CustomerID
GROUP BY CustomerID
ORDER BY NumberOfPurchases DESC LIMIT 0,5;

试图写一个COUNT（*）查询

1 个答案: