mysql - 如何将2行结果合并为1行

Question

我有一个查询，它只会生成 2 行。每一行包含一个问题及其匹配的答案。我想做的是单行 4 列。如何才能做到这一点？我可以将这些值连接到一个字符串中，但我不想这样做。

有人能给我举个例子吗？这就是我所追求的:

Q1              A1            Q2                 A2 
Some question   Some answer   Another question   Another answer

<小时/>

这是我的查询

SELECT question, answer FROM
user_question AS uq
Join question AS q ON q.question_id = uq.question_id

Answer 1

当然可以，只需查询同一张表两次即可。您应该使用 AS 关键字，这样您就可以确定 SELECT 和 WHERE 部分中使用的是哪个版本的表:

SELECT a.question as q1,
       a.answer as a1,
       b.question as q2,
       b.answer as a2
FROM   user_question as a,
       user_question as b
WHERE  a.question_id = 1001
AND    b.question_id = 1002;