Hibernate11_映射关系---OneToOne双向

OneToOne双向是在One2One单向基础上修改 1、IDCard不变 IDC实体类

package com.chb.model;

public class IDCard {
    private int id;
    private String no;
    private Person person;


    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getNo() {
        return no;
    }
    public void setNo(String no) {
        this.no = no;
    }
    public Person getPerson() {
        return person;
    }
    public void setPerson(Person person) {
        this.person = person;
    }
}

IDCard.hbm.xml

2、只需在Person类中添加IDCard对象， 在Person.hbm.xml中设置设置one-to-one关联， 设置property-ref=”person”表名有对端（IDCard）中的person对象维护关系 2.1、Person实体类

package com.chb.model;

public class Person  {
    private int id;
    private String name;
    private IDCard idCard;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public IDCard getIdCard() {
        return idCard;
    }
    public void setIdCard(IDCard idCard) {
        this.idCard = idCard;
    }



}

2.2、Person.hbm.xml

3、测试 3.1、one2one双向添加测试。

package com.chb.model;
import org.hibernate.Session;
import com.chb.hbUtils.HibernateUtils;
public class Test {
    @org.junit.Test
    public void test01() {
        Session session = null;
        //获取session
        session = HibernateUtils.getSession();
        //开启事务
        session.beginTransaction();

        //测试添加
        IDCard idCard = new IDCard();
        idCard.setNo("001");
        session.save(idCard);

        Person p = new Person();
        p.setName("chb");
        p.setIdCard(idCard);
        session.save(p);

        //提交事务
        session.getTransaction().commit();
        HibernateUtils.close();
    }
}

3.2、测试结果：是由IDCard端的person对象维护关系。所以通过p.setIdCard(idCard)就无效， 所以没有关联关系。

执行的sql

Hibernate: 

    create table t_id_card (
       c_id integer not null auto_increment,
        no varchar(255),
        p_id integer,
        primary key (c_id)
    ) engine=InnoDB
Hibernate: 

    create table t_person (
       p_id integer not null auto_increment,
        p_name varchar(255),
        primary key (p_id)
    ) engine=InnoDB
Hibernate: 

    alter table t_id_card 
       drop index UK_3dn8d7nqti422123arcwiwcni
Hibernate: 

    alter table t_id_card 
       add constraint UK_3dn8d7nqti422123arcwiwcni unique (p_id)
Hibernate: 

    alter table t_id_card 
       add constraint FKka2jsnojthq1ip58u1fqnlfwh 
       foreign key (p_id) 
       references t_person (p_id)
Hibernate: 
    insert 
    into
        t_id_card
        (no, p_id) 
    values
        (?, ?)
Hibernate: 
    insert 
    into
        t_person
        (p_name) 
    values
        (?)

4、先添加person, 在添加IDCard，

package com.chb.model;
import org.hibernate.Session;
import com.chb.hbUtils.HibernateUtils;
public class Test {
    @org.junit.Test
    public void test01() {
        Session session = null;
        //获取session
        session = HibernateUtils.getSession();
        //开启事务
        session.beginTransaction();

        //测试添加
        //先添加person
        Person p = new Person();
        p.setName("wx");
        session.save(p);
        //再添加IDCard
        IDCard idCard = new IDCard();
        idCard.setNo("002");
        idCard.setPerson(p);
        session.save(idCard);


        //提交事务
        session.getTransaction().commit();
        HibernateUtils.close();
    }
}

结果：

5、load测试， 从person端获取

6、load测试， 从idCard端获取

7、最佳实践