在单个查询中按 Asc 和 Desc 排序

Question

我有一个查询可以从 table 检索最新数据，分页工作正常。

但是一旦数据比当前时间更早，它也应该出现在最新数据之后。

SELECT A.UserId,A.FirstName,A.LastName,A.PostDate
(SELECT ROW_NUMBER() OVER(ORDER BY CAST(M.PostDate AS DATETIMEOFFSET) DESC) AS 'RowNumber'
    M.UserId,
   M.FirstName,
            M.LastName,
    M.PostDate
    FROM Messages AS M
   Where M.PostDate >= GetDate()
) A
       WHERE A.RowNumber BETWEEN @RowStart AND @RowEnd 
 ORDER BY CAST(A.PostDate AS DATETIMEOFFSET)  DESC

Answer 1

我认为你应该删除下面这行

Where M.PostDate >= GetDate()

Answer 2

你不能在 Table 的同一列上做 Order By ASC 和 DESC 如果你这样做你会得到以下错误

Msg 169, Level 15, State 1, Line 1 A column has been specified more than once in the order by list. Columns in the order by list must be unique.

如果你想要它，你可以使用相同 Table 的 Join 并按相同的列排序，如

SELECT A.UserId,A.FirstName,A.LastName,A.PostDate
(SELECT ROW_NUMBER() OVER(ORDER BY CAST(M.PostDate AS DATETIMEOFFSET) DESC) AS 'RowNumber'
   M.UserId,
   M.FirstName,
   M.LastName,
   M.PostDate
    FROM Messages AS M
   Where M.PostDate >= GetDate()
) A
 Inner Join Messages AS Msg on Msg.UserId=A.UserId
WHERE A.RowNumber BETWEEN @RowStart AND @RowEnd 
ORDER BY CAST(A.PostDate AS DATETIMEOFFSET) DESC,
         CAST(Msg.PostDate AS DATETIMEOFFSET)  ASC

Answer 3

我不确定我是否得到了您正在寻找的东西，但这应该能让您接近。我创建了一个包含两个计算列的 CTE：

BeforeAfter，确定日期是在传入日期之前还是之后
AbsDiff，给出日期差异的绝对值。

然后，我只使用这两个字段进行排序：

DECLARE @current datetime = GETDATE()
;WITH cteMessages AS 
(
    SELECT UserId, FirstName, LastName, PostDate, 
    CASE WHEN PostDate < @current THEN 1 ELSE 0 END AS BeforeAfter,
    ABS(DATEDIFF(SECOND, @current, PostDate)) AS AbsDiff
    FROM Messages
)
SELECT * FROM cteMessages
ORDER BY BeforeAfter, AbsDiff

从这些结果中，您可以看到它们是如何首先按比传入日期新的邮件排序，然后按与旧邮件相反的顺序排序的。您可以将该顺序替换为 Row_Number 函数。

在单个查询中按 Asc 和 Desc 排序

Order By Asc and Desc both in single query

sql-server

azure-sql-database