Select 从多个表中汇总

Question

我有 2 个表，它们是：

和

我想 select 每个订单中的总项目行金额，由单价*数量、总折扣 = sum(((数量 * 单价)/100) * 折扣*100) 和平均运费 = （Freight/Total 订单项）* 总订单项

我这样写 select 语句：

select  Orders.OrderID,CustomerID, EmployeeID, ProductID,ShippedDate, RequiredDate, ShipVia,(Freight/sum(Quantity))*Quantity 'TotalFreight', 
Quantity * UnitPrice 'LineItemTotal',sum(Quantity) 'Line Item Quantity',sum(((Quantity * UnitPrice)/100) * Discount*100) 'Total Line Discount',Discount  from Orders
inner join [Order Details] on Orders.OrderID = [Order Details].OrderID
group by Orders.OrderID,Orders.CustomerID, Orders.EmployeeID, [Order Details].ProductID, Orders.RequiredDate, Orders.ShipVia, Orders.Freight, [Order Details].Quantity,[Order Details].UnitPrice, [Order Details].Discount, Orders.ShippedDate

但是，它并没有正确计算AverageFreight。我究竟做错了什么？

Answer 1

您不需要对此进行汇总。 window 函数应该足够了：

select o.*, od.*, 
       (Freight / order_quantity)*Quantity as AllocatedFreight, 
       Quantity * UnitPrice as LineItemTotal,
       Quantity as [Line Item Quantity],
       (((Quantity * UnitPrice)/100) * Discount*100) as [Total Line Discount,
       Discount 
from Orders o inner join
     (select od.*, sum(quantity) over (partition by od.orderId) as order_quantity
      from [Order Details] od
     ) od
     on o.OrderID = od.OrderID;

Select 从多个表中汇总

Select aggregate from multiple tables

sql

group-by

aggregate

dml