Question

问题标题几乎总结了它。

我正在加入两个表，其结果是按时间戳列排序的，＆amp;按升序排序（因此最近的行位于底部）。在这种情况下如何获得最后20行？

代码（假设两个表是表A和表B）：

SELECT A.*, B.some_column
                FROM A
                INNER JOIN B ON B.id = A.id AND (other conditions here)
                ORDER BY A.timestamp ASC
                LIMIT 20

目前返回前20行。我需要最后20个。

P.S。我需要将最终结果集按ASCENDING顺序排序。最近的行需要在最后，而不是开头！

Answer 1

如果您想在查询中通过ASC订购，您可以：

SELECT A.*, B.some_column
                FROM A
                INNER JOIN B ON B.id = A.id
                WHERE id IN (SELECT * FROM (
                 SELECT id FROM A ORDER BY timestamp DESC LIMIT 20
                ) AS s) ORDER BY A.timestamp ASC

Answer 2

试试这个

SELECT * FROM 
(
   SELECT A.*, B.some_column
                FROM A
                INNER JOIN B ON B.id = A.id AND (other conditions here)
                ORDER BY A.timestamp Desc
                LIMIT 20
) Temp
ORDER BY A.timestamp ASC

Answer 3

SELECT * FROM (

        SELECT A.*, B.some_column
                FROM A
                INNER JOIN B ON B.id = A.id AND (other conditions here)
                ORDER BY A.timestamp DESC
                LIMIT 20

    ) AS RESULT

    ORDER BY RESULT.timestamp ASC

Answer 4

反转结果的顺序，

在SQL Server中，使用：

select top 20 ...

在MySQL中，使用：

select ... order by num desc limit 20

Answer 5

首先，按另一种方式排序：

ORDER BY `timestamp` DESC
LIMIT 0,20

在ASC排序时获得最后20行内部联接

5 个答案: