SQL Server:带有UNION的子查询中的ORDER BY

Question

我有两个查询与UNION ALL¹组合:

--Query 1
SELECT Flavor, Color
FROM Friends

 

--Query 2
SELECT Flavor,
    (SELECT TOP 1 Color
     FROM Rainbows
     WHERE Rainbows.StrangerID = Strangers.StrangerID
     ORDER BY Wavelength DESC
    ) AS Color
FROM Strangers

当然,这两者都可以单独工作,但当与以下内容结合使用时UNION ALL:

SELECT Flavor, Color
FROM Friends

UNION ALL

SELECT Flavor,
    (SELECT TOP 1 Color
     FROM Rainbows
     WHERE Rainbows.StrangerID = Strangers.StrangerID
     ORDER BY Wavelength DESC
    ) AS Color
FROM Strangers

查询失败并显示错误:

如果语句包含UNION运算符,则消息104,级别15,状态1,行3 ORDER BY项必须出现在选择列表中.

如何在UNION ALL的语句中使用ORDER BY？

复制 - 可粘贴示例

CREATE TABLE Friends (Flavor int, Color int)
CREATE TABLE Strangers (Flavor int, StrangerID int)
CREATE TABLE Rainbows (StrangerID int, Color int, Wavelength int)
go

SELECT Flavor, Color
FROM Friends

UNION ALL

SELECT Flavor,
    (SELECT TOP 1 Color
     FROM Rainbows
     WHERE Rainbows.StrangerID = Strangers.StrangerID
     ORDER BY Wavelength DESC
    ) AS Color
FROM Strangers
go

DROP TABLE Rainbows
DROP TABLE Strangers
DROP TABLE Friends

服务器:消息104,级别15,状态1,行2
ORDER BY项目必须出现在选择列表中,如果该语句包含UNION运算符.

脚注

• ¹受挫的假设例子.或不.

也可以看看

• SQL查询 - 在UNION中使用Order By
• SQL UNION和ORDER BY
• SQL:在使用Order By的UNION查询中使用Top 1
• 投影中相关子查询的排序影响

Answer 1

有点黑客,但这会奏效.

CREATE TABLE Friends (Flavor int, Color int)
CREATE TABLE Strangers (Flavor int, StrangerID int)
CREATE TABLE Rainbows (StrangerID int, Color int, Wavelength int)
go

SELECT Flavor, Color
FROM Friends

UNION ALL

SELECT Flavor,
    (SELECT Color FROM 
        (SELECT TOP 1 Color, Wavelength
         FROM Rainbows
         WHERE Rainbows.StrangerID = Strangers.StrangerID
         ORDER BY Wavelength DESC
         ) AS Foo
    ) AS Color
FROM Strangers
go

DROP TABLE Rainbows
DROP TABLE Strangers
DROP TABLE Friends