hibernate的基础学习--一对多关联

基本的用户和部门类,只有uuid和名称,没有其余字段。

配置文件

部门:

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <!DOCTYPE hibernate-mapping PUBLIC 
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5 <!-- 映射配置 -->
 6 <hibernate-mapping>
 7     <class name="hib.po.Dept" table="dept" schema="hibernatedb">
 8         <!-- 类的唯一标示和表中的主键映射 -->
 9         <id name="deptId" column="dept_id">
10             <!-- 主键生成策略:native(mysql自增) -->
11             <generator class="uuid"></generator>
12         </id>
13         
14         <property name="deptName" column="deptname"></property>
15         
16         <!-- 关系字段:用户  one2many
17             name:关联关系属性
18             class:关联关系属性的类型
19             column:指定生成表中的关系字段名称(外键名)
20             inverse="true":放弃维护关系功能
21          -->
22         <set name="users" inverse="false">
23             <!-- column: 用来对应 关联表(t_user)中的外键名称 -->
24             <key column="dept_id"></key>
25             <!-- class:关联关系属性(集合)中的元素的类型 -->
26             <one-to-many class="hib.po.User"/>
27         </set>
28     </class>
29 </hibernate-mapping>
View Code

用户:

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <!DOCTYPE hibernate-mapping PUBLIC 
 3     "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
 4     "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
 5 <!-- 映射配置 -->
 6 <hibernate-mapping>
 7     <class name="hib.po.User" table="user" schema="hibernatedb">
 8         <!-- 类的唯一标示和表中的主键映射 -->
 9         <id name="userId" column="user_id">
10             <!-- 主键生成策略:native(mysql自增) -->
11             <generator class="uuid"></generator>
12         </id>
13         
14         <!-- 普通属性和普通字段映射 -->
15         <property name="username" column="username"></property>
16         
17         <!-- 关系字段:部门  many2one
18             name:关联关系属性
19             class:关联关系属性的类型
20             column:指定生成表中的关系字段名称(外键名)
21          -->
22         <many-to-one 
23         name="dept" 
24         class="hib.po.Dept"
25         column="dept_id"
26         ></many-to-one>
27     </class>
28 </hibernate-mapping>
View Code

 

基础的增删改查方法

 1 /**
 2  * @author nunu
 3  * 测试hibernate OneToMany 
 4  */
 5 public class TestHibernateOneToMany {
 6 
 7     /**
 8      * 添加用户
 9      */
10     @Test
11     public void addUser() {
12         SessionFactory sf = H3Util.getSessionFactory();
13         Session session = sf.openSession();
14         Transaction ts = session.beginTransaction();
15         User s1 = new User(null, "小小", null);
16         User s2 = new User(null, "小五", null);
17         session.save(s1);
18         session.save(s2);
19         
20         ts.commit();
21         session.close();
22     }
23     
24     /**
25      * 添加部门
26      */
27     @Test
28     public void addDept() {
29         SessionFactory sf = H3Util.getSessionFactory();
30         Session session = sf.openSession();
31         Transaction ts = session.beginTransaction();
32         Dept dept1 = new Dept(null, "研发部", null);
33         Dept dept2 = new Dept(null, "人事部", null);
34         Dept dept3 = new Dept(null, "财务部", null);
35         session.save(dept1);
36         session.save(dept2);
37         session.save(dept3);
38         
39         ts.commit();
40         session.close();
41     }
42     
43     /**
44      * 从员工端维护关系:多端维护
45      */
46     @Test
47     public void updateMany(){
48         SessionFactory sf = H3Util.getSessionFactory();
49         Session session = sf.openSession();
50         Transaction ts = session.beginTransaction();
51         
52         User user1 = (User) session.get(User.class, "ff80808157c82de80157c82deb2d0000");
53         Dept dept1 = (Dept) session.get(Dept.class, "ff80808157c831050157c83106b10000");
54         System.out.println(dept1.getDeptName());
55         //从用户角度维护关系:将部门对象添加到用户中
56         user1.setDept(dept1);
57         
58         //最后加上
59         session.update(user1);
60         
61         ts.commit();
62         session.close();
63         System.out.println("====");
64     }
65     
66     /**
67      * 从一端维护关系
68      */
69     @Test
70     public void updateOne() {
71         SessionFactory sf = H3Util.getSessionFactory();
72         Session session = sf.openSession();
73         Transaction ts = session.beginTransaction();
74         
75         User user1 = (User) session.get(User.class, "ff80808157c831830157c83184a90000");
76         Dept dept1 = (Dept) session.get(Dept.class, "ff80808157c831050157c83106c40001");
77         System.out.println(dept1.getDeptName());
78         //从部门角度维护关系:将用户对象添加到部门中
79         Set<User> users = dept1.getUsers();
80         users.add(user1);        
81         
82         dept1.setUsers(users);
83         
84         session.update(dept1);
85         
86         ts.commit();
87         session.close();
88         System.out.println("====");
89     }
90     
91 }

 

posted @ 2016-10-17 14:16  小小暮雨  阅读(204)  评论(0编辑  收藏  举报