Card類

public class Card {

    private int id;
    private String cardNo;
    private String address;

    private Person person;

....

Person類

public class Person {

    private int id;
    private String name;

    private Card card;
    ......

PersonDao類

public interface PersonDao {

    List<Person> getPersons() throws
 
 Exception;

    Person getPersonById(int id) throws Exception;

}

CardDao類

public interface CardDao {

    List<Card> getCards() throws Exception;

    Card getCardById(int id) throws Exception;

}

CardDao.xml 對映檔案

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 

<mapper namespace="com.hsj.dao.CardDao">


    <select id="getCards" resultMap="resultMap_Card">
        select * from t_card c inner join t_person p on c.person_id=p.p_id
    </select>

    <resultMap type="card" id="resultMap_Card">
        <id column="c_id" property="id"
 
/>
        <result column="c_cardno" property="cardNo"/>
        <result column="c_address" property="address"/>
        <association property="person" column="person_id" javaType="person">
            <id column="p_id" property="id"/>
            <result column="p_name" property="name"/>
        </association>
    </resultMap>


    <select id="getCardById" parameterType="int" resultMap="resultMap_Card">
        select * from t_card c inner join t_person p on c.person_id=p.p_id and c_id=#{id}
    </select>
</mapper>

PersonDao.xml對映檔案

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
 PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hsj.dao.PersonDao">


    <select id="getPersons" resultMap="resultMap_Person">
        select * from t_person p inner join t_card c on p.p_id=c.person_id
    </select>

    <resultMap type="person" id="resultMap_Person">
        <id column="p_id" property="id"/>
        <result column="p_name" property="name"/>
        <association property="card" column="person_id" javaType="card">
            <id column="c_id" property="id"/>
            <result column="c_cardno" property="cardNo"/>
            <result column="c_address" property="address"/>
        </association>
    </resultMap>


    <select id="getPersonById"  parameterType="int" resultMap="resultMap_Person">
        select * from t_person p inner join t_card c on p.p_id=c.person_id and p_id=#{id}
    </select>
</mapper>

其中的一個測試類 public class PersonDaoTest {

private PersonDao personDao;
@Before
public void setUp() throws Exception {
    SqlSession sqlSession=MyBatisUtils.getSqlSession();
    this.personDao=sqlSession.getMapper(PersonDao.class);
}

@Test
public void testGetPersons() {

    try {
        List<Person> persons=this.personDao.getPersons();
        for(Person p:persons){
            System.out.println(p+"==>"+p.getCard());

        }

    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

@Test
public void testGetPerson() {
    try {
        int id=1;
        Person person=this.personDao.getPersonById(id);
        System.out.println(person+"==>"+person.getCard());

    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

}