关联关系-下手-一对一单向外键

关联关系-动手-一对一单向外键

/**
 * Person类中有一个属性指向另外一个实体,但是另外一个实体没有属性指向Person,所以单向
 * 由于Person表中是非主键属性关联,所以外键
 * @author Macrotea
 *
 */
@Entity
public class Person {
	private int id;
	private String name;
	private Address address;
	
	@OneToOne
	@JoinColumn(name = "addressId") 
	public Address getAddress() {
		return address;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public String getName() {
		return name;
	}
	public void setAddress(Address address) {
		this.address = address;
	}
	public void setId(int id) {
		this.id = id;
	}
	public void setName(String name) {
		this.name = name;
	}
	@Override
	public String toString() {
		return "Person [id=" + id + ", name=" + name + "]";
	}
}



@Entity
public class Address {
	private int id;
	private String city;
	public String getCity() {
		return city;
	}
	@Id
	@GeneratedValue
	public int getId() {
		return id;
	}
	public void setCity(String city) {
		this.city = city;
	}
	public void setId(int id) {
		this.id = id;
	}
	@Override
	public String toString() {
		return "Address [city=" + city + ", id=" + id + "]";
	}
}


public class Test {
	private static void prepare_data() {

		Session session = HibernateSessionFactory.getSession();
		Transaction transaction = session.beginTransaction();
		transaction.begin();

		for (int i = 1; i <= 5; i++) {
			Address addr = new Address();
			addr.setCity("广州-" + i);

			Person p = new Person();
			p.setName("macrotea-" + i);
			p.setAddress(addr);

			session.save(addr);
			session.save(p);
		}

		transaction.commit();
		session.close();
	}

	private static void test_load() {
		Session session = HibernateSessionFactory.getSession();
		Transaction transaction = session.beginTransaction();
		transaction.begin();
		Person p=(Person)session.get(Person.class, 1);
		transaction.commit();
		session.close();
		
		System.out.println(p.toString());
		System.out.println(p.getAddress().toString());
	}

	public static void main(String[] args) {
		//prepare_data();
		 test_load();
	}
}

 

<hibernate-mapping package="com.macrotea.hb.model">
	<class name="Person">
		<id name="id">
			<generator class="native" />
		</id>
		<property name="name" />
		<!--若OneToOneunique="true",而addressId为Person表生成的列名-->
		<many-to-one name="address" column="addressId" unique="true"/> 
	</class>
</hibernate-mapping>


<hibernate-mapping package="com.macrotea.hb.model">
	<class name="Address">
		<id name="id">
			<generator class="native" />
		</id>
		<property name="city" />
	</class>
</hibernate-mapping>