How to use the specified data generated using a binary tree PHP?
Here is my Database
CREATE TABLE IF NOT EXISTS yy_user_relations (
id bigint(32) unsigned NOT NULL AUTO_INCREMENT,
uid int(10) unsigned NOT NULL COMMENT 'User ID',
cid int(10) unsigned NOT NULL COMMENT 'Parent ID',
deep int(5) unsigned NOT NULL COMMENT 'Deep',
area tinyint(1) unsigned NOT NULL DEFAULT '0' COMMENT 'Area',
PRIMARY KEY (id),
KEY ucda (uid,cid,deep,area) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=114 DEFAULT CHARSET=utf8mb4 COMMENT='关系';
INSERT INTO yy_user_relations (id, uid, cid, deep, area) VALUES
(108, 71, 1, 1, 0),
(109, 72, 71, 1, 0),
(110, 72, 1, 2, 0),
(111, 73, 1, 1, 1),
(112, 74, 73, 1, 1),
(113, 74, 1, 2, 1);
area = 0 left, area=1 right