在SQL Server中使用帶有ORDER的UNION

Question

我想使用UNION檢索兩個表的最新記錄，即使使用ORDER BY，它也會返回數據但不是最新記錄。這是我的查詢：

SELECT TOP(1) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
FROM TheaterNews 
    UNION 
    SELECT TOP(3) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
FROM MoviesNews 
    ORDER BY 3 DESC 

這是查詢的輸出：

但TheaterNews最新的記錄是新的：

SELECT OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
FROM TheaterNews 
ORDER BY NewsCreationDate DESC 

我怎樣才能解決這個問題？即使用另一種方法。

Answer 1

這應該在你的情況下工作。可能是一個粗略的解決方案，但你會得到你的答案。你可以用@tables替換#tables。

SELECT TOP(1) 
    OwnerID, 
    NewsTitle, 
    NewsCreationDate, 
    NewsEnglishName 
into 
    #Table1 
FROM 
    TheaterNews 
ORDER BY 3 DESC 

SELECT TOP(3) 
    OwnerID, 
    NewsTitle, 
    NewsCreationDate, 
    NewsEnglishName 
into 
    #Table2 
FROM 
    MoviesNews 
ORDER BY 3 DESC 

select * from #Table1 
union 
select * from #Table2 

drop table #Table1 
drop table #Table2 

Answer 2

試試這個：

Select * From (SELECT TOP(1) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
    FROM TheaterNews ORDER BY NewsCreationDate DESC) as tempA 
     UNION 
    Select * From (SELECT TOP(3) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
    FROM MoviesNews ORDER BY NewsCreationDate DESC) as tempB 

Answer 3

的order by適用於工會，而不是單獨的查詢的全部結果，這樣的結果進行排序之前top應用。

使用子查詢訂購單獨的結果：

SELECT * FROM (
    SELECT TOP(1) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
    FROM TheaterNews 
    ORDER BY 3 DESC 
) x 
UNION 
SELECT * FROM (
    SELECT TOP(3) OwnerID,NewsTitle,NewsCreationDate,NewsTitle,NewsEnglishName 
    FROM MoviesNews 
    ORDER BY 3 DESC 
) y 

Answer 4

由於TOP子句是越來越ORDER BY子句前執行。通過嘗試這種

Select * from (SELECT TOP(1) OwnerID,NewsTitle,NewsCreationDate,  
        NewsEnglishName 
       FROM TheaterNews  ORDER BY 3 DESC) as tn 
    UNION 
    Select * From (SELECT TOP(3)  
       OwnerID,NewsTitle,NewsCreationDate,NewsEnglishName 
       FROM MoviesNews  ORDER BY 3 DESC) as mn 
    ORDER BY 3 DESC 

外訂單將責令聯合的結果