MySQL子查詢別名

Question

當我在where子句中使用子查詢別名時，出現未知列錯誤：

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

誰能告訴我為什么此代碼不起作用？

Answer 1

用另一種方法來做：

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

Answer 2

我認為您可以在沒有子選擇的情況下進行查詢

 select a.name, b.id as children  
 from category as a
 inner join category b on ( a.c1.id = b.id  and b.parent_id = 23 );