mysql - 提供子行时从同一个表中选择父行

Question

"id"    "parent"    "name"
"1"     "0"         "Books"
"2"     "1"         "Crime Fiction"
"3"     "2"         "Death On the Nile"

从类似上面的内容中，我如何选择name父行的名称以及child. 在这里，将提供子行的名称。我需要得到name父母的。

期望的输出：

@id = 3

Crime Fiction //This is the name of the parent row - in this case 2
     Death on the Nile // This is the name of the row who's id was supplied.

如何在同一张表中进行选择？

Answer 1

select parent.name, child.name
from your_table child
left join your_table parent on child.parent = parent.id
where child.id = 3

Answer 2

SELECT (CASE WHEN p.name IS NULL THEN "???" ELSE p.name END) AS name 
FROM <your_table> c LEFT JOIN <your_table> p
ON c.parent = p.id
WHERE c.name = <yourname>
LIMIT 1;

此查询将返回给定子名称的父名称，或“???” 如果它找不到父母。

Answer 3

select t1.name, t2.name as parent_name from tablename t1 join tablename t2
on t1.id=t2.parent where t1.id=3