Question

在开始之前，我想让你知道我正在使用着名的微软Northwind数据库。

所以，我需要创建一个函数来检索以下结果集：

Query需要创建一个函数，该函数接收国家名称（表Orders的shipCountry字段）作为参数，并且必须输出雇员的姓氏（表Employees的lastName字段）和总金额每个员工每年（1996,1997,1998）在该职能的输入中收到的收入。

当我谈到他们所赚取的总收入时，我指的是总结订单的所有单价。（我使用了字段：unitPrice，表格的数量和折扣[订单明细]）

在这里，我向你们展示我所做的查询，这样你就可以更好地了解我想要做什么，我的问题是我不知道在哪里放置国名的条件（正如我所说的那样）必须根据我们在函数中插入的国家/地区显示信息：

CREATE FUNCTION fn_listAnualAmounts(@country NVARCHAR)
RETURNS TABLE
AS
BEGIN
    DECLARE @anio96 MONEY, @anio97 MONEY, @anio98 MONEY 

    SET @anio96 = (SELECT SUM((od.UnitPrice - od.Discount)*od.quantity) as [Año 1996]
                    FROM [Order Details] od 
                        left join Orders o on o.OrderID = od.OrderID
                        left join Employees e on e.EmployeeID = o.EmployeeID
                    GROUP BY YEAR(o.OrderDate),e.EmployeeID
                    HAVING YEAR(o.OrderDate) = '1996')
    SET @anio97 = (SELECT SUM((od.UnitPrice - od.Discount)*od.quantity) as [Año 1997]
                    FROM [Order Details] od 
                        left join Orders o on o.OrderID = od.OrderID
                        left join Employees e on e.EmployeeID = o.EmployeeID
                    GROUP BY YEAR(o.OrderDate),e.EmployeeID
                    HAVING YEAR(o.OrderDate) = '1997')
    SET @anio98 = (SELECT SUM((od.UnitPrice - od.Discount)*od.quantity) as [Año 1998]
                    FROM [Order Details] od 
                        left join Orders o on o.OrderID = od.OrderID
                        left join Employees e on e.EmployeeID = o.EmployeeID
                    GROUP BY YEAR(o.OrderDate),e.EmployeeID
                    HAVING YEAR(o.OrderDate) = '1998')

    RETURN (SELECT e.LastName, @anio96, @anio97, @anio98
            FROM Employees e)
END
GO

此处您有northwind数据库图表

非常感谢你们所有人！

Answer 1

只需使用条件聚合：

SELECT e.LastName,
       SUM(CASE WHEN YEAR(o.OrderDate) = 1996
                THEN (od.UnitPrice - od.Discount)*od.quantity
           END) as total_1996
       SUM(CASE WHEN YEAR(o.OrderDate) = 1997
                THEN (od.UnitPrice - od.Discount)*od.quantity
           END) as total_1997,
       SUM(CASE WHEN YEAR(o.OrderDate) = 1998
                THEN (od.UnitPrice - od.Discount)*od.quantity
           END) as total_1998
FROM [Order Details] od LEFT JOIN
     Orders o 
     ON o.OrderID = od.OrderID LEFT JOIN
     Employees e 
     ON e.EmployeeID = o.EmployeeID
GROUP BY e.EmployeeId, e.LastName;

SQL Server - 使用northwind数据库创建函数

1 个答案: