Hibernate之one-to-one主鍵關聯映射

one-to-one映射的例子為一個人擁有一個身份證，一個身份證屬於一個人。

先創建po類

Person.java

1. package po;
3. public class Person {
4. private int id;
5. private String name; //姓名
6. public int getId() {
7. return id;
8. }
9. public void setId(int id) {
10. this.id = id;
11. }
12. public String getName() {
13. return name;
14. }
15. public void setName(String name) {
16. this.name = name;
17. }
19. }

1. package po;
3. public class Card {
4. private int id; //身份證ID
5. private String number; //身份證號碼
6. private Person person; //一個身份證號對應一個人
8. public int getId() {
9. return id;
10. }
11. public void setId(int id) {
12. this.id = id;
13. }
14. public String getNumber() {
15. return number;
16. }
17. public void setNumber(String number) {
18. this.number = number;
19. }
20. public Person getPerson() {
21. return person;
22. }
23. public void setPerson(Person person) {
24. this.person = person;
25. }
30. }

Person.hbm.xml

1. <hibernate-mapping>
2. <class name="po.Person" table="person">
3. <id name="id" type="integer">
4. <generator class="native" />
5. </id>
6. <property name="name" />
7. </class>
9. </hibernate-mapping>

1. <hibernate-mapping>
2. <class name="po.Card" table="card">
3. <id name="id" type="integer">
4. <!-- 主鍵生成方式為foreign -->
5. <generator class="foreign">
6. <param name="property">person</param>
7. </generator>
8. </id>
9. <property name="number"></property>
10. <!-- !!!constrained=true表示生成外鍵約束 -->
11. <one-to-one name="person" constrained="true"></one-to-one>
12. </class>
13. </hibernate-mapping>

1. <hibernate-configuration>
3. <session-factory>
4. <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
5. <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
6. <property name="connection.username">root</property>
7. <property name="connection.password">1</property>
8. <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
9. <property name="myeclipse.connection.profile">mysql</property>
10. <property name="show_sql">true</property>
11. <property name="format_sql">true</property>
12. <mapping resource="po/Person.hbm.xml"/>
13. <mapping resource="po/Card.hbm.xml"/>
14. </session-factory>
15. </hibernate-configuration

1. package po;
3. import java.util.Date;
4. import java.util.HashSet;
5. import java.util.Iterator;
6. import java.util.Set;
8. import org.hibernate.Session;
9. import org.hibernate.SessionFactory;
10. import org.hibernate.cfg.Configuration;
11. import org.hibernate.tool.hbm2ddl.SchemaExport;
12. import org.junit.Test;
15. public class Test {
17. @Test
18. public void testCreateDB(){
19. //生成表結構
20. Configuration config = new Configuration().configure();
21. SchemaExport export = new SchemaExport(config);
22. export.create(true, true);
23. }
24. @Test
25. public void testSave(){
26. //測試 添加數據
27. Configuration config = new Configuration().configure();
28. SessionFactory factory = config.buildSessionFactory();
29. Session session = factory.openSession();
30. session.beginTransaction();
33. Person person = new Person(); //先有person然後才能有省份證
34. person.setName("zhangsan");
36. Card card = new Card();
37. card.setNumber("4114031111222223333");
38. card.setPerson(person); //此身份證屬於此人
39. session.save(card); //保存card
41. session.getTransaction().commit();
43. }
44. @Test
45. public void testGetPerson(){
46. Configuration config = new Configuration().configure();
47. SessionFactory factory = config.buildSessionFactory();
48. Session session = factory.openSession();
49. session.beginTransaction();
51. Card card = (Card)session.get(Card.class,1 ); //取出Card
52. System.out.println("CardNumber: "+card.getNumber());
54. Person person = card.getPerson(); //通過card.getPerson()方法 返回person
55. System.out.println("PersonName: "+person.getName()); //取出person的name
57. session.getTransaction().commit();
58. session.close();
59. }
60. }

1. create table card (
2. id integer not null,
3. number varchar(255),
4. primary key (id)
5. )
7. create table person (
8. id integer not null auto_increment,
9. name varchar(255),
10. primary key (id)
11. )
12. alter table card
13. add index FK2E7B10F83A3F5F (id),
14. add constraint FK2E7B10F83A3F5F
15. foreign key (id)
16. references person (id)