Question

我有三张桌子，我需要计算2015年约翰史密斯的营业额除以月份。

                   OrderItems
                   ------------       Orders
Products           OrderItem_ID       ------
----------         Order_ID   <--->   Order_ID
Product_ID  <--->  Product_ID         Type
Name               Quantity           Date
Category           UnitPrice          Customer

表格通过Order_ID＆amp; amp; Order_ID（选项卡OrderItems和Orders），然后按Product_IDs（选项卡Products和OrderItems）。我想我还是不需要制表产品。

Orders (Order_ID INT, Type INT, Date DATETIME, Customer VARCHAR)
OrderItems (OrderItem_ID INT, Order_ID INT, Product_ID INT, Quantity INT, UnitPrice MONEY)
Products (Product_ID INT, Name VARCHAR, Category VARCHAR)

由于我最后一次使用SQL已经有很长一段时间了，因此谷歌搜索和知识刷新了几十分钟和几十分钟。

我写了这个查询，但我完全不确定。你能来看看吗？

SELECT
    SUM(a.quantity * a.price) AS 'turnover',
    DATEPART(month, a.date) AS 'month'
FROM 
(
    SELECT  
        Quantity.OrderItems AS 'quantity',
        UnitPrice.OrderItems AS 'price',
        Date.Orders AS 'date',
        Customer.Orders AS 'customer'
    FROM Orders
    JOIN Orders 
        ON OrderItems.Order_ID = Orders.Order_ID
    WHERE
        date BETWEEN 2015-01-01 and 2015-12-31
        AND customer = 'John Smith'
) a
GROUP BY month
ORDER BY month

非常感谢

//纠正了代码中的一个小错误

Answer 1

您需要将Orders加入OrderItems

SELECT
    SUM(a.quantity * a.price) AS 'turnover',
    DATEPART(month, a.date) AS 'month'
FROM 
(
    SELECT  
        OI.Quantity AS 'quantity',
        OI.UnitPrice AS 'price',
        O.Date AS 'date',
        O.Customer AS 'customer'
    FROM Orders O
    INNER JOIN OrderItems OI
        ON O.Order_ID = OI.Order_ID
    WHERE
        O.date BETWEEN 2015-01-01 and 2015-12-31
        AND O.customer = 'John Smith'
) a
GROUP BY DATEPART(month, a.date)
ORDER BY DATEPART(month, a.date)

SQL计算营业额和逐月计算（请检查）

1 个答案: