04.Hibernate一对一关联

CREATE TABLE tb_customer
(
    id              bigint          NOT NULL    auto_increment          COMMENT ‘ID‘,
    name            varchar(50)     NOT NULL                            COMMENT ‘客户名称‘,
    home_address    bigint                                              COMMENT ‘客户家庭地址‘,
    PRIMARY KEY (id)
) COMMENT = ‘客户信息表‘;

CREATE TABLE tb_address
(
    id              bigint          NOT NULL    auto_increment          COMMENT ‘ID‘,
    zipcode         varchar(50)     NOT NULL                            COMMENT ‘邮政编码‘,
    address         varchar(200)    NOT NULL                            COMMENT ‘地址‘,
    PRIMARY KEY (id)
) COMMENT = ‘地址信息表‘;
-- 可选的外键约束
ALTER TABLE tb_customer ADD CONSTRAINT fk_tb_customer_tb_address_1 FOREIGN KEY (home_address) REFERENCES tb_address (id);

package model;
public class Address
{
	private Long id;
	private String zipcode;
	private String address;
	private Customer customer;
	@Override
	public String toString()
	{
		return "Address [id=" + id + ", zipcode=" + zipcode + ", address=" + address + ", customer=" + customer.getName() + "]";
	}
	// 省略setter、getter...
}

<hibernate-mapping package="model">
	<class name="Address" table="tb_address">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="zipcode" column="zipcode" />
		<property name="address" column="address" />
		<one-to-one name="customer" class="model.Customer" property-ref="homeAddress"/>
	</class>
</hibernate-mapping>

<hibernate-mapping package="model">
	<class name="Customer" table="tb_customer">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" column="name" />
		<many-to-one name="homeAddress" class="model.Address" column="home_address" unique="true" cascade="all"/>
	</class>
</hibernate-mapping>

public static void main(String[] args)
{
    Customer customer;
    Address address;
    Configuration cfg = new Configuration();
    cfg.configure();
    ServiceRegistry sr = new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();
    SessionFactory sf = cfg.buildSessionFactory(sr);
    System.out.println("连接数据库");
    Session session = sf.openSession();
    Transaction transaction = session.beginTransaction();
    try
    {
        customer=new Customer();
        address=new Address();
        customer.setName("测试客户01");
        address.setZipcode("123456");
        address.setAddress("湖北省武汉市");

        customer.setHomeAddress(address);
        address.setCustomer(customer);
        session.save(customer);//配置使用了级联保存
        transaction.commit();
    }
    catch (Exception e)
    {
        transaction.rollback();
        System.out.println("错误：" + e);
    }
    finally
    {
        session.close();
        System.out.println("关闭数据库");
    }
    System.exit(0);
}

连接数据库
Hibernate: insert into tb_address (zipcode, address) values (?, ?)
Hibernate: insert into tb_customer (name, home_address) values (?, ?)
关闭数据库

<hibernate-mapping package="model">
	<class name="Address" table="tb_address">
		<id name="id">
			<generator class="foreign">
				<param name="property">customer</param>
			</generator>
		</id>
		<property name="zipcode" column="zipcode" />
		<property name="address" column="address" />
		<one-to-one name="customer" class="model.Customer" constrained="true"/>
	</class>
</hibernate-mapping>

<hibernate-mapping package="model">
	<class name="Customer" table="tb_customer">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" column="name" />
		<one-to-one name="homeAddress" class="model.Address" cascade="all"/>
	</class>
</hibernate-mapping>

连接数据库
Hibernate: insert into tb_customer (name) values (?)
Hibernate: insert into tb_address (zipcode, address) values (?, ?)
关闭数据库

<one-to-one name="PropertyName" 
    access="field|property"
    class="ClassName"
    property-ref="PropertyNameFromAssociatedClass"
    constrained="true|false"
    formula="arbitrary SQL expression"
    cascade="all|none|save-update|delete"
    fetch="join|select"
    outer-join="true|false"
    foreign-key="foreign-key"
    lazy="true|false"
    embed-xml="true|false"
    entity-name="EntityName"
    node="element-name"/>