mysql递归查询上下级

最近作项目遇到地区查询问题，涉及递归，在java代码中处理发现效率较低，遂考虑使用sql递归

贴上一张表结构：

1、查询下级方法

CREATE FUNCTION getChildrenOrg (orgid INT) RETURNS VARCHAR (4000)
BEGIN
DECLARE oTemp VARCHAR (4000);
DECLARE oTempChild VARCHAR (4000);
SET oTemp = '';
SET oTempChild = CAST(orgid AS CHAR);
WHILE oTempChild IS NOT NULL DO
SET oTemp = CONCAT(oTemp, ',', oTempChild);
SELECT
	GROUP_CONCAT(areaid) INTO oTempChild
FROM
	area
WHERE
	FIND_IN_SET(parentid, oTempChild) > 0;
END
WHILE;
RETURN oTemp;
END

调用方法（查询areaid为620000（甘肃）的地区的所有下级）

SELECT
	*
FROM
	area
WHERE
	FIND_IN_SET(
		areaid,
		getChildrenOrg (620000)
	)

结果：

1、查询上级方法

SELECT *
    FROM ( 
        SELECT 
                @r AS _id, 
                (SELECT @r := parentid FROM area WHERE areaid = _id) AS parent_id, 
                 @l := @l + 1 AS lvl 
        FROM 
                (SELECT @r := 330324, @l := 0) vars, 
                area h 
        WHERE @r <> 0) T1 
    JOIN area T2 
    ON T1._id = T2.areaid
ORDER BY areaid;

注意其中的330324就是子节点areaid

结果以下：