Sql 如何同时选择两个选择和

我试着用这个公式

像这样

sum((freight/sum(Quantity))*Quantity) for lineitemfright

我试过的代码没有求和我想要的一个值

select sum(
     (
        Northwind.dbo.orders.Freight 
        /
        (
            select SUM(
                Northwind.dbo.[Order Details].Quantity
            )
            from Northwind.dbo.[Order Details] 
            where Northwind.dbo.[Order Details].OrderID = Northwind.dbo.orders.OrderID
        )
        *
        Northwind.dbo.[Order Details].Quantity
    )
) as LineItemFreight 
from Northwind.dbo.[Order Details] 
inner join Northwind.dbo.Orders 
on Northwind.dbo.[Order Details].OrderID= northwind.dbo.Orders.OrderID
where Northwind.dbo.orders.ShippedDate is not null

然而，它不断得到一个错误的说法

Msg 130, Level 15, State 1, Line 5
Cannot perform an aggregate function on an expression containing an aggregate or a subquery.
 sum((freight/sum(Quantity))*Quantity)

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我试图在不使用分组依据的情况下求和一个值。

使用变量并执行此操作

  @DECLARE @tEMPSUM bigint

    SET @TEMPSUM=select SUM(Northwind.dbo.[Order Details].Quantity)from Northwind.dbo.[Order Details] 
            where Northwind.dbo.[Order Details].OrderID = Northwind.dbo.orders.OrderID

然后

---

你用的是哪一个数据库？我用的是一个叫Northwind的数据库。当我计算出一个总数时，我得到了多个数字，我只想得到一个数字。选择Northwind.dbo.orders.Freight/选择SUMNorthwind.dbo。[订单详细信息]。来自Northwind.dbo的数量。[订单详细信息]其中Northwind.dbo。[订单详细信息]。OrderID=Northwind.dbo.orders.OrderID*Northwind.dbo。[订单详细信息]数量为来自Northwind.dbo的LineItemFreightNorthwind.dbo上的内部联接Northwind.dbo.Orders。[订单详细信息].OrderID=Northwind.dbo.Orders.OrderID，其中Northwind.dbo.Orders.ShippedDate不是空的。我指的是哪个数据库供应商mysql、sqlserver、oracle、postgres等。解决方案可能取决于这一事实。

select sum((Northwind.dbo.orders.Freight / @tEMPSUM)*Northwind.dbo.[Order Details].Quantity) as LineItemFreight 
from Northwind.dbo.[Order Details] 
inner join Northwind.dbo.Orders 
on Northwind.dbo.[Order Details].OrderID= northwind.dbo.Orders.OrderID
where Northwind.dbo.orders.ShippedDate is not null