閉包表記錄了樹中所有節(jié)點的關系，不僅僅只是直接父子關系，它需要使用2張表，除了節(jié)點表本身之外，還需要使用1張表來存儲節(jié)祖先點和后代節(jié)點之間的關系（同時增加一行節(jié)點指向自身）,
并且根據(jù)需要，可以增加一個字段，表示深度。因此這種方法數(shù)據(jù)量很多。設計的表結(jié)構(gòu)如下：

create table `node` (`id` int(10) not null,`name` varchar(50) default null,primary key (`id`) ) engine=innodb default charset=utf8;create table `tree_path` (`anc` int(10) not null comment '祖先節(jié)點',`des` int(10) not null comment '子孫節(jié)點',`pc` int(1) default null comment '是否為父子節(jié)點 1/0',primary key (`anc`,`des`) ) engine=innodb default charset=utf8;-- 示例樹 -- root(0) -- | -- a(1) -- |___a1(2) -- |___a2(3) -- b(4) -- |___b1(5) -- |___b2(6) -- |___c(7) -- |___c1(8) -- |___d(9) -- |___e(10)insert into node(id,name) values (0,'root'); insert into node(id,name) values (1,'a'); insert into node(id,name) values (2,'a1'); insert into node(id,name) values (3,'a2'); insert into node(id,name) values (4,'b'); insert into node(id,name) values (5,'b1'); insert into node(id,name) values (6,'b2'); insert into node(id,name) values (7,'c'); insert into node(id,name) values (8,'c1'); insert into node(id,name) values (9,'d'); insert into node(id,name) values (10,'e');insert into tree_path(anc,des,pc) values (0,1,1); insert into tree_path(anc,des,pc) values (0,2,0); insert into tree_path(anc,des,pc) values (0,3,0); insert into tree_path(anc,des,pc) values (0,4,1); insert into tree_path(anc,des,pc) values (0,5,0); insert into tree_path(anc,des,pc) values (0,6,0); insert into tree_path(anc,des,pc) values (0,7,0); insert into tree_path(anc,des,pc) values (0,8,0); insert into tree_path(anc,des,pc) values (0,9,0); insert into tree_path(anc,des,pc) values (0,10,0);insert into tree_path(anc,des,pc) values (1,1,0); insert into tree_path(anc,des,pc) values (2,2,0); insert into tree_path(anc,des,pc) values (3,3,0); insert into tree_path(anc,des,pc) values (4,4,0); insert into tree_path(anc,des,pc) values (5,5,0); insert into tree_path(anc,des,pc) values (6,6,0); insert into tree_path(anc,des,pc) values (7,7,0); insert into tree_path(anc,des,pc) values (8,8,0); insert into tree_path(anc,des,pc) values (9,9,0); insert into tree_path(anc,des,pc) values (10,10,0);insert into tree_path(anc,des,pc) values (1,2,1); insert into tree_path(anc,des,pc) values (1,3,1);insert into tree_path(anc,des,pc) values (4,5,1); insert into tree_path(anc,des,pc) values (4,6,1); insert into tree_path(anc,des,pc) values (4,7,1); insert into tree_path(anc,des,pc) values (4,8,0); insert into tree_path(anc,des,pc) values (4,9,0); insert into tree_path(anc,des,pc) values (4,10,0);insert into tree_path(anc,des,pc) values (7,8,1); insert into tree_path(anc,des,pc) values (7,9,1); insert into tree_path(anc,des,pc) values (7,10,0);insert into tree_path(anc,des,pc) values (9,10,1);刪除子樹 假設要刪除子樹#7delete from tree_path where tree_path.des in (select t.des from tree_path t where t.anc=7)移動子樹 假設我們要把子樹#7從節(jié)點#4移動到節(jié)點#1 1.分離子樹,刪除子樹節(jié)點與其祖先的關系 delete from tree_path where tree_path.anc=72.將上一步分離出的子樹用笛卡爾積嫁接到#1下 selectsuper.anc,sub.des,casewhensuper.anc=1 and sub.des=7 then 1else 0end pc fromtree_path supercross jointree_path sub wheresuper.des=1 and sub.anc=7查詢樹形結(jié)構(gòu) xxxxxx

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