Question

不知道我是否用规范化覆盖了它，但是有4个表：

员工（ID，姓名）
产品（ID，名称，价格）
Order_Details（ID，Employee_ID {FK}，月，年）-购买时间和进行销售的员工
Order_Each_Product（订单ID {PK，FK}，产品ID {PK，FK}，数量）-购买了哪种产品以及购买了每种产品的数量

我想要这样的东西：

( Employee_Name, Month, Total_Sales_Made_In_That_Month_In_Dollar )

我认为您可以从2张桌子中获得每个订单的总和，例如：

SELECT SUM((Order_Each_Product.Quantity) * (Product.Price)) 
FROM Order_Each_Product 
INNER JOIN Product ON Order_Each_Product.ProductID = Product.ProductID
GROUP BY OrderID

但是您如何再次按员工将其分组并获得SUM的SUM？

Answer 1

在我编写代码时，Forpas击败了我！

SELECT
    Employee.Name, Year, Month, SUM(Quantity * Price) AS Total_Sales_In_Month
FROM 
    Order_Details

LEFT JOIN Employee
    ON (Order_Details.Employee_ID = Employee.ID)

LEFT JOIN Order_Each_Product
    ON (Order_Details.ID = Order_Each_Product.OrderID)

LEFT JOIN Product
    ON (Order_Each_Product.ProductID = Product.ID)

GROUP BY
    Employee.ID, Employee.Name, Year, Month

提示，您当前所称的Order_Details和Order_Each_Product通常分别称为order_headers和order_lines。

Answer 2

按员工的ID，姓名，年和月加入所有表和组：

select
  e.name,
  od.Year,
  od.Month,
  sum(oep.quantity * p.price) Total_Sales_Made_In_That_Month_In_Dollar
from employee e 
inner join order_details od on od.employee_id = e.id
inner join order_each_product oep on oep.orderid = od.id
inner join product p on p.id = oep.productid
group by e.id, e.name, od.Year, od.Month

SQL Server Management Studio一个月的销售总额

2 个答案: