06hibernate_one2one_pk_2(you can forget)

package com.bjsxt.hibernate;

import org.hibernate.Session;

import junit.framework.TestCase;

public class One2OneTest extends TestCase {

    public void testSave1() {
        Session session = null;
        try {
            session = HibernateUtils.getSession();
            session.beginTransaction();
            
            IdCard idCard = new IdCard();
            idCard.setCardNo("88888888888888");
            
            Person person = new Person();
            person.setName("孙悟空");
            person.setIdCard(idCard);
            
            //不会出现TransientObjectException异常
            //因为一对一主键关联映射中，默认了cascade属性
            session.save(person);
            
            session.getTransaction().commit();
        }catch(Exception e) {
            e.printStackTrace();
            session.getTransaction().rollback();
        }finally {
            HibernateUtils.closeSession(session);
        }
    }        
    
    public void testLoad1() {
        Session session = null;
        try {
            session = HibernateUtils.getSession();
            session.beginTransaction();
            
            Person person = (Person)session.load(Person.class, 1);
            System.out.println("person.name=" + person.getName());
            System.out.println("idCard.cardNo=" + person.getIdCard().getCardNo());
            session.getTransaction().commit();
        }catch(Exception e) {
            e.printStackTrace();
            session.getTransaction().rollback();
        }finally {
            HibernateUtils.closeSession(session);
        }
    }        

    public void testLoad2() {
        Session session = null;
        try {
            session = HibernateUtils.getSession();
            session.beginTransaction();
            
            IdCard idCard = (IdCard)session.load(IdCard.class, 1);
            System.out.println("idcard.cardNo=" + idCard.getCardNo());
            System.out.println("idcard.person.name=" + idCard.getPerson().getName());
            
            session.getTransaction().commit();
        }catch(Exception e) {
            e.printStackTrace();
            session.getTransaction().rollback();
        }finally {
            HibernateUtils.closeSession(session);
        }
    }        
    
}
--------------------------------------------------
hibernate一对一主键关联映射（双向关联Person<---->IdCard）

//需要在idcard映射文件中加入<one-to-one>标签指向person:<one-to-one name="person"/>，
//指示hibernate如何加载person默认根据主键加载

<hibernate-mapping>
    <class name="com.bjsxt.hibernate.IdCard" table="t_idcard">
        <id name="id">
            <generator class="native"/>
        </id>
        <property name="cardNo"/>
        <one-to-one name="person"/>
    </class>
</hibernate-mapping>


create table t_idcard (id integer not null auto_increment, cardNo varchar(255), primary key (id))

create table t_person (id integer not null, name varchar(255), primary key (id))

alter table t_person add index FK785BED809AC0D5D6 (id), add constraint FK785BED809AC0D5D6 foreign key (id) references t_idcard (id)

mysql> desc t_idcard;
+--------+--------------+------+-----+---------+----------------+
| Field  | Type         | Null | Key | Default | Extra          |
+--------+--------------+------+-----+---------+----------------+
| id     | int(11)      | NO   | PRI | NULL    | auto_increment |
| cardNo | varchar(255) | YES  |     | NULL    |                |
+--------+--------------+------+-----+---------+----------------+
2 rows in set (0.14 sec)

mysql> desc t_person;
+-------+--------------+------+-----+---------+-------+
| Field | Type         | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+-------+
| id    | int(11)      | NO   | PRI | NULL    |       |
| name  | varchar(255) | YES  |     | NULL    |       |
+-------+--------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
TestSave：
Hibernate: insert into t_idcard (cardNo) values (?)
Hibernate: insert into t_person (name, id) values (?, ?)

TestLoaded1：
Hibernate: select person0_.id as id1_0_, person0_.name as name1_0_ from t_person person0_ where person0_.id=?
person.name=孙悟空
Hibernate: select idcard0_.id as id0_1_, idcard0_.cardNo as cardNo0_1_, person1_.id as id1_0_, person1_.name as name1_0_ from t_idcard idcard0_ left outer join t_person person1_ on idcard0_.id=person1_.id where idcard0_.id=?
idCard.cardNo=88888888888888

TestLoaded2：
Hibernate: select idcard0_.id as id0_1_, idcard0_.cardNo as cardNo0_1_, person1_.id as id1_0_, person1_.name as name1_0_ from t_idcard idcard0_ left outer join t_person person1_ on idcard0_.id=person1_.id where idcard0_.id=?
idcard.cardNo=88888888888888
idcard.person.name=孙悟空