mysql 查询所有父级名称

SELECT T2.id, T2.name
FROM (
    SELECT
        @r AS _id,
        @stop:=@stop+if(@r=2,1,@stop) as stop,
        (SELECT @r := p_id FROM goods_class WHERE id = _id) AS p_id,
        @l := @l + 1 AS lvl
    FROM
        (SELECT @r := 39, @l := 0, @stop:=0) vars,
        goods_class h
    WHERE @stop < 1) T1
JOIN goods_class T2
ON T1._id = T2.id
ORDER BY T1.lvl DESC