mysql

根据某一个id查出所有父级、祖级、包括当前节点 1234567891011121314151617SELECT T2.* FROM ( SELECT @r AS _id, ( SELECT @r := parent_id FROM sys_city WHERE id = _id ) AS parent_id, @l := @l + 1 AS lvl FROM ( SELECT @r := 真实id, @l := 0 ) vars, sys_city h WHERE @r <> 0 ) T1 JOIN sys_city T2 ON T1._id = T2.id ORDER BY T1.lvl DESC 根据某一个父级id查出所有子级、孙级、包括当前节点 1234567891011121314151617SELECT id, name, parent_id FROM (SELECT t1.id, IF(FIND_IN_SET(parent_id,...