oracle中查找一个节点的父节点和子节点

1、建表

--菜单目录结构表
create table tb_menu(
  id number(10) not null, --主键id
  title varchar2(50), --标题
  parent number(10) --parent id
)

2、造测试数据

--父菜单
insert into tb_menu(id, title, parent) values(1, '父菜单1',null);
insert into tb_menu(id, title, parent) values(2, '父菜单2',null);
insert into tb_menu(id, title, parent) values(3, '父菜单3',null);
insert into tb_menu(id, title, parent) values(4, '父菜单4',null);
insert into tb_menu(id, title, parent) values(5, '父菜单5',null);
--一级菜单
insert into tb_menu(id, title, parent) values(6, '一级菜单6',1);
insert into tb_menu(id, title, parent) values(7, '一级菜单7',1);
insert into tb_menu(id, title, parent) values(8, '一级菜单8',1);
insert into tb_menu(id, title, parent) values(9, '一级菜单9',2);
insert into tb_menu(id, title, parent) values(10, '一级菜单10',2);
insert into tb_menu(id, title, parent) values(11, '一级菜单11',2);
insert into tb_menu(id, title, parent) values(12, '一级菜单12',3);
insert into tb_menu(id, title, parent) values(13, '一级菜单13',3);
insert into tb_menu(id, title, parent) values(14, '一级菜单14',3);
insert into tb_menu(id, title, parent) values(15, '一级菜单15',4);
insert into tb_menu(id, title, parent) values(16, '一级菜单16',4);
insert into tb_menu(id, title, parent) values(17, '一级菜单17',4);
insert into tb_menu(id, title, parent) values(18, '一级菜单18',5);
insert into tb_menu(id, title, parent) values(19, '一级菜单19',5);
insert into tb_menu(id, title, parent) values(20, '一级菜单20',5);
--二级菜单
insert into tb_menu(id, title, parent) values(21, '二级菜单21',6);
insert into tb_menu(id, title, parent) values(22, '二级菜单22',6);
insert into tb_menu(id, title, parent) values(23, '二级菜单23',7);
insert into tb_menu(id, title, parent) values(24, '二级菜单24',7);
insert into tb_menu(id, title, parent) values(25, '二级菜单25',8);
insert into tb_menu(id, title, parent) values(26, '二级菜单26',9);
insert into tb_menu(id, title, parent) values(27, '二级菜单27',10);
insert into tb_menu(id, title, parent) values(28, '二级菜单28',11);
insert into tb_menu(id, title, parent) values(29, '二级菜单29',12);
insert into tb_menu(id, title, parent) values(30, '二级菜单30',13);
insert into tb_menu(id, title, parent) values(31, '二级菜单31',14);
insert into tb_menu(id, title, parent) values(32, '二级菜单32',15);
insert into tb_menu(id, title, parent) values(33, '二级菜单33',16);
insert into tb_menu(id, title, parent) values(34, '二级菜单34',17);
insert into tb_menu(id, title, parent) values(35, '二级菜单35',18);
insert into tb_menu(id, title, parent) values(36, '二级菜单36',19);
insert into tb_menu(id, title, parent) values(37, '二级菜单37',20);
--三级菜单
insert into tb_menu(id, title, parent) values(38, '三级菜单38',21);
insert into tb_menu(id, title, parent) values(39, '三级菜单39',22);
insert into tb_menu(id, title, parent) values(40, '三级菜单40',23);
insert into tb_menu(id, title, parent) values(41, '三级菜单41',24);
insert into tb_menu(id, title, parent) values(42, '三级菜单42',25);
insert into tb_menu(id, title, parent) values(43, '三级菜单43',26);
insert into tb_menu(id, title, parent) values(44, '三级菜单44',27);
insert into tb_menu(id, title, parent) values(45, '三级菜单45',28);
insert into tb_menu(id, title, parent) values(46, '三级菜单46',28);
insert into tb_menu(id, title, parent) values(47, '三级菜单47',29);
insert into tb_menu(id, title, parent) values(48, '三级菜单48',30);
insert into tb_menu(id, title, parent) values(49, '三级菜单49',31);
insert into tb_menu(id, title, parent) values(50, '三级菜单50',31);
commit;
 
select * from tb_menu;

3、--查找一个节点的所有直属子节点（所有后代）

select * from tb_menu m 
start with m.id = 3
connect by m.parent = prior m.id;

4、---查找一个节点的直属父节点（父亲）

select c.id, c.title, p.id parent_id, p.title parent_title
from tb_menu c, tb_menu p
where c.parent = p.id and c.id = 9;

2、树操作
我们从最基本的操作，逐步列出树查询中常见的操作，所有查询出来的节点以家族中的辈份作比方。

1)、查找树中的所有顶级父节点（辈份最长的人）。假设这个树是个目录结构，那么第一个操作总是找出所有的顶级节点，再根据该节点找到其下属节点。

select * from tb_menu m where m.parent is null;

2)、查找一个节点的直属子节点（所有儿子）。如果查找的是直属子类节点，也是不用用到树型查询的。

select * from tb_menu m where m.parent=1;

3)、查找一个节点的所有直属子节点（所有后代）。

select * from tb_menu m start with m.id=1 connect by m.parent=prior m.id;

4)、查找一个节点的直属父节点（父亲）。

select c.id, c.title, p.id parent_id, p.title parent_title
from tb_menu c, tb_menu p
where c.parent=p.id and c.id=6

5)、查找一个节点的所有直属父节点（祖宗）。

select * from tb_menu m start with m.id=38 connect by prior m.parent=m.id;

6)、查询一个节点的兄弟节点（亲兄弟）。

--m.parent=m2.parent-->同一个父亲
select * from tb_menu m
where exists (select * from tb_menu m2 where m.parent=m2.parent and m2.id=6)

7)、查询与一个节点同级的节点（族兄弟）。如果在表中设置了级别的字段，那么在做这类查询时会很轻松，同一级别的就是与那个节点同级的，在这里列出不使用该字段时的实现!

with tmp as(
      select a.*, level leaf        
      from tb_menu a                
      start with a.parent is null     
      connect by a.parent = prior a.id)
select *                               
from tmp                             
where leaf = (select leaf from tmp where id = 50);

8)、查询一个节点的父节点的的兄弟节点（伯父与叔父）。

with tmp as(
    select tb_menu.*, level lev
    from tb_menu
    start with parent is null
    connect by parent = prior id)
    
select b.*
from tmp b,(select *
            from tmp
            where id = 21 and lev = 2) a
where b.lev = 1
 
union all
 
select *
from tmp
where parent = (select distinct x.id
                from tmp x, --祖父
                     tmp y, --父亲
                     (select *
                      from tmp
                      where id = 21 and lev > 2) z --儿子
                where y.id = z.parent and x.id = y.parent);

9)、查询一个节点的父节点的同级节点（族叔）。

with tmp as(
      select a.*, level leaf        
      from tb_menu a                
      start with a.parent is null     
      connect by a.parent = prior a.id)
select *                               
from tmp                             
where leaf = (select leaf from tmp where id = 6) - 1;

oracle中查找一个节点的父节点和子节点

猜你喜欢