mysql 查询 所有 父节点 单表

SELECT
	T2.*
FROM
	(
		SELECT
			@r AS _id,
			(
				SELECT
					@r := parent_id
				FROM
					tp_module_rel
				WHERE
					REL_ID = _id
			) AS parent_id,
			@l := @l + 1 AS lvl
		FROM
			(SELECT @r := 254, @l := 0) vars,
			tp_module_rel h
		WHERE
			@r <> 0
	) T1
JOIN tp_module_rel T2 ON T1._id = T2.rel_id
ORDER BY
	T1.lvl DESC;

　使用了临时表 。 

在别的博客里面看到，忘了地址。。 记下 做备用

SELECTT2.*FROM(SELECT@r AS _id,(SELECT@r := parent_idFROMtp_module_relWHEREREL_ID = _id) AS parent_id,@l := @l + 1 AS lvlFROM(SELECT @r := 254, @l := 0) vars,tp_module_rel hWHERE@r <> 0) T1JOIN tp_module_rel T2 ON T1._id = T2.rel_idORDER BYT1.lvl DESC;