Question

我必须从不同的表中获取最新的前1项，并根据desc中的日期对结果进行排序，然后根据日期选择前1条记录

SELECT TOP 1 PublishDate, 'Article' FROM Articles ORDER BY PublishDate
UNION ALL
SELECT TOP 1 PublishDate, 'News' FROM News ORDER BY NewsDate
UNION ALL
SELECT TOP 1 CreateDate, 'Blog' FROM Blog ORDER BY BlogDate
UNION ALL
SELECT TOP 1 PostDate, 'Videos' FROM Videos ORDER BY NewsDate

结果我应该根据最新发布日期有最新的1条记录。

我尝试在存储过程的所有语句中使用ORDER BY，但它不起作用，因为它会引发错误。如何使用此查询或CTE查询获得所需结果。

我正在使用SQL Server 2008

Answer 1

尝试制作另一个子选择：

select top 1 date, type from 
(SELECT 
   TOP 1  PublishDate as date, 'Article' as type 
   FROM Articles 
   ORDER BY  PublishDate 
 UNION ALL SELECT 
   TOP 1  PublishDate as date, 'News' as type 
   FROM News ORDER BY  NewsDate 
 UNION ALL SELECT TOP 1  CreateDate as date, 'Blog' as type 
   FROM Blog ORDER BY  BlogDate 
   UNION ALL SELECT TOP 1  PostDate as date, 'Videos' as type 
   FROM Videos ORDER BY  NewsDate) as unions 
order by date

Answer 2

这个怎么样：

select * from 
(SELECT TOP 1  PublishDate, 'Article'  as description FROM Articles 
UNION ALL
SELECT TOP 1  PublishDate, 'News' FROM News 
UNION ALL
SELECT TOP 1  CreateDate, 'Blog' FROM Blog 
UNION ALL
SELECT TOP 1  PostDate, 'Videos' FROM Videos) as a ORDER BY description

SQL Server中使用UNION ALL的多个SQL语句

2 个答案: