树结构在开发中经常遇到。例如：部门、菜单、员工架构等等。下面用部门作为例子构造部门结构树

1、部门表：dept

-- ----------------------------

-- Table structure for dept

-- ----------------------------

DROP TABLE IF EXISTS `dept`;

CREATE TABLE `dept` (

`id` varchar(36) NOT NULL,

`name` varchar(255) DEFAULT NULL,

`parent_id` varchar(36) DEFAULT NULL,

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2、实体类：Dept

public class Dept implements Serializable {

private static final long serialVersionUID = -2809004220612317111L;

//ID

private String id;

//部门名称

private String name;

//父ID

private String parentId;

//get/set方法省略

}