Hibernate之one-to-one外鍵關聯映射

在hibernate一對一實體映射中，常用有兩種方式，一種就是把一對一看作多對一的一個特例，即通過外鍵參考。

另一種是通過主鍵參考，限制兩個數據表中的主鍵使用相同的值。

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. }

1. <hibernate-mapping>
2. <class name="po.Card" table="card">
3. <id name="id" type="integer">
4. <generator class="native" />
5. </id>
6. <property name="number"></property>
7. <!-- 是多對一的一種特例 unique=true設置為唯一關聯 -->
8. <many-to-one name="person" unique="true" column="person"></many-to-one>
9. </class>
10. </hibernate-mapping>

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" />
8. </class>
9. </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>