Mysql根据子ID查询父ID

SELECT _id as cid
    FROM ( 
        SELECT 
                @r AS _id, 
                (SELECT @r := parentid FROM bee_category_info WHERE cid = _id) AS parentid, 
                 @l := @l + 1 AS lvl 
        FROM 
                (SELECT @r := 10000, @l := 0) vars, 
                bee_category_info h 
        WHERE @r <> 0) T1 
    JOIN bee_category_info T2 
    ON T1._id = T2.cid
where _id<>10000
ORDER BY cid;