准备表和数据

create table node_tree(

id int NOT NULL AUTO_INCREMENT PRIMARY KEY, id

node_name varchar(128) NOT NULL DEFAULT '', 节点名字

up_node_id int, 上级结点id

node_level char(1) 节点等级

) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_swedish_ci;

insert into node_tree(node_name,up_node_id,node_level)

values

('jx', NULL, '1'),

('jx.webserver', 1, '2'),

('jx.webserver.nginx1', 2, '3'),

('jx.logserver', 1, '2')

insert into node_tree(node_name,up_node_id,node_level)

values

('jx.logserver.logstash1', 4, '3')

create table node_tree1(

id int NOT NULL AUTO_INCREMENT PRIMARY KEY,

name varchar(128) NOT NULL DEFAULT '',

level char(1)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_swedish_ci;

create table node_tree2(

id int NOT NULL AUTO_INCREMENT PRIMARY KEY,

name varchar(128) NOT NULL DEFAULT '',

up_id int,

level char(1)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_swedish_ci;

insert into node_tree1(name, level)

values

('yx', '1');

insert into node_tree2(name, up_id, level)

values

('jx.webserver', 1, '2'),

('jx.logserver', 1, '2')

insert into node_tree1(name, level)

values

('xs', '1');

insert into node_tree2(name, up_id, level)

values

('xs.webserver', 2, '2');

查询jx节点的子节点

select node_tree.node_name,nt2.node_name from node_tree,node_tree as nt2 where

node_tree.node_name='jx' and node_tree.id=nt2.up_node_id

有一个表的别名是nt2，相当于将两个表连接起来，两个表之间有一定的关系