MySQL选择内部限制 [英] mysql select inside limit

问题描述

select
  id
from
  tableABC
limit (select count(id) from tableCBA), 1

如果我需要如示例代码所示在限制中进行选择，如何在mySql中进行选择?这只是本论坛的简化代码，否则，如果不选择，这就是复杂情况的一部分.

If I need select in limit as I have shown here in sample code, how can I do this in mySql? This is only simplified code for purpose of this forum, otherwise this is a part of sophisticated case when else select.

推荐答案

您不能直接为限制设置动态值，但是您可以在没有限制的情况下重新编写查询，如下所示:

You can't directly have a dynamic value for limit, but your query can be re-written without the limit, as follows:

set i := (select count(*) from tableCBA);
select id
from tableABC
where (i := i-1) = 0;

这将返回第n行，其中n是tableCBA中的行数；

This will return the nth row, where n is the number of rows in tableCBA;

这篇关于MySQL选择内部限制的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！