Postgres将子查询结果用括号括起来 [英] Postgres wraps subquery results in parentheses

问题描述

不要注意所提供查询的无用性，它只是复杂查询的简化部分。

Don't pay attention to uselessness of the provided query, it's just a simplified part of a complex one.

我运行查询：

SELECT elem FROM (SELECT id FROM data) AS elem;

其结果为：

 elem 
------
 (5)
 (4)
 (24)
 (3)
 (23)

为什么每个值都括在括号中？

Why does each value enclosed in parentheses?

所以，要解决这个问题，我会做：

So, to fix it I do:

SELECT trim(elem::text, ')(') FROM (SELECT id FROM data) AS elem;

我觉得不应该那样...

I have a feeling it should not be that way...

推荐答案

SELECT elem.id FROM (SELECT id FROM data) AS elem;

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