MySQL 向上递归查询树节点

SELECT T2.CATL_ID, T2.CATL_NM FROM (     SELECT         @r AS _id,         (SELECT @r := supr_catl_id FROM T_KM_DOC_CATALOG WHERE CATL_ID = _id) AS supr_catl_id,         @l := @l + 1 AS lvl     FROM         (SELECT @r := 1020101, @l := 0) vars,         T_KM_DOC_CATALOG h     WHERE @r <> 0) T1 JOIN T_KM_DOC_CATALOG T2 ON T1._id = T2.CATL_ID ORDER BY T1.lvl DESC