mysql从子类id查询所有父类

表结构

id name parent_id---------------------------1 Home 02 About 13 Contact 14 Legal 25 Privacy 46 Products 17 Support 1 

 

mysql代码如下：

SELECT T2.id, T2.nameFROM ( 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) T1JOIN table1 T2ON T1._id = T2.idORDER 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'