mysql从子类id查询所有父类

 

  mysql从子类id查询所有父类 收藏

表结构

 

id  name    parent_id
---------------------------
1   Home        0
2   About       1
3   Contact     1
4   Legal       2
5   Privacy     4
6   Products    1
7   Support     1

 

 

mysql代码如下：

 

SELECT T2.id, T2.name
FROM (
    SELECT
        @r AS _id,
        (SELECT @r := parent_id FROM table1 WHERE id = _id) AS parent_id,
        @l := @l + 1 AS lvl
    FROM
        (SELECT @r := 5, @l := 0) vars,
        table1 h
    WHERE @r <> 0) T1
JOIN table1 T2
ON T1._id = T2.id
ORDER BY T1.lvl DESC

 

 

代码@r := 5标示查询id为5的所有父类。结果如下

 

1, 'Home'
2, 'About'
4, 'Legal'
5, 'Privacy'