Mysql子查询别名

Question

当我在 where 子句中使用子查询别名时，出现未知列错误:

SELECT name, 
(SELECT id FROM category c2 WHERE c2.parent_id=23) children 
FROM category c1 WHERE c1.id IN children;

有人能告诉我为什么这段代码不起作用吗？

Answer 1

反过来做:

SELECT name, 
FROM category c1 
WHERE c1.id IN (SELECT id FROM category c2 WHERE c2.parent_id=23);