创建一个函数来计算订单成本SQL Server

Question

我正在尝试创建一个函数，该函数将基于此公式计算OrderCost

((1.0 – Discount) * (UnitPrice * Quantity))

不确定我在哪里出错。.尝试运行查询时收到此错误消息

  

第102行，状态15，状态1，过程OrderCost，第7行[批处理开始第0行]
  '–'附近的语法不正确。

CREATE FUNCTION [dbo].[OrderCost] (@i INT)
RETURNS int
AS
BEGIN
    DECLARE @OrderCost INT

    SELECT @OrderCost = SUM((1.0 – Discount) * (UnitPrice * Quantity))
    FROM OrderDetails

    RETURN @OrderCost
END

Answer 1

将减号'–'更改为'-'

 CREATE FUNCTION [dbo].[OrderCost](@i int)
    RETURNS int
    AS
    BEGIN
        DECLARE @OrderCost int

        SELECT @OrderCost = SUM((1.0 - Discount) * (UnitPrice * Quantity))
        FROM OrderDetails

        RETURN @OrderCost
    END

Answer 2

如果您在那里有20个订单怎么办？您需要知道选哪个！

CREATE FUNCTION [dbo].[OrderCost](@i int, @OrderId Int, @ProductId Int)
RETURNS int
AS
BEGIN
    DECLARE @OrderCost int

    SELECT @OrderCost = SUM((1.0 - Discount) * (UnitPrice * Quantity))
    FROM OrderDetails
    Where OrderId = @OrderId and ProductId = @ProductId

    RETURN @OrderCost
END