子查询是重用变量的唯一选择吗? [英] Are subqueries the only option to reuse variables?

问题描述

我想以这种形式使用MySQL:

I'd like to use MySQL in this form:

SELECT 1 AS one, one*2 AS two

因为它更短更甜美

SELECT one*2 AS two FROM ( SELECT 1 AS one ) AS sub1

但是前者似乎不起作用，因为它希望其中一个成为一列.

but the former doesn't seem to work because it expects one to be a column.

有没有更简单的方法来实现这种效果而无需子查询?

Is there any easier way to accomplish this effect without subqueries?

不，SELECT 2 AS two不是选项. ;)

推荐答案

select @one := 1 as one, 2 * @one as two;

用户定义的变量

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