MySQL 子结点查询所有父结点（查询结果包含自身结点）

SQL代码

SELECT t2.id, t2.`menuname`
FROM
    (
        SELECT 
        @r AS _id,
        (SELECT @r := parentid FROM t_menu WHERE id = _id) AS parent_id,
        @l := @l + 1 AS lvl
        FROM
        (SELECT @r := '644', @l := 0) vars, t_menu AS h
        WHERE @r != 0 
    ) t1
JOIN t_menu t2
ON t1._id = t2.Id

@r := '644'

这里输入子结点的ID

 查询结果

 页面树状结构