mybatis关联查询

CREATE TABLE test.mobile
(
mid INT NOT NULL auto_increment,
tel VARCHAR (50),
pid INT,
PRIMARY KEY (mid)
);

CREATE TABLE test.person
(
pid  INT NOT NULL auto_increment,
name VARCHAR (50),
PRIMARY KEY (pid)
);
INSERT INTO test.person (name)
VALUES ('wjf');
INSERT INTO test.mobile (tel, pid)
VALUES ('13564089643', 1);

INSERT INTO test.mobile (tel, pid)
VALUES ('13511111111', 1);

<?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="wjf.dao.MobileMapper">
<resultMap type="wjf.Obj.Mobile" id="resultMap">
<id property="mid" column="mid" />
<result property="tel" column="tel" />
<association property="person" javaType="wjf.Obj.Person"
column="pid">
<id property="pid" column="pid" />
<result property="name" column="name" />
</association>
</resultMap>
<select id="getMobile" parameterType="int" resultMap="resultMap">
select
p.pid,p.name ,m.mid ,m.tel
from person p ,mobile m where m.pid=p.pid
AND m.mid=#{id}
</select>
<select id="getALLMobile" resultMap="resultMap">
select
p.pid,p.name ,m.mid
,m.tel
from person p ,mobile m where m.pid=p.pid
</select>
</mapper>

<?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="wjf.dao.PersonMapper">
<resultMap type="wjf.Obj.Person" id="resultMap">
<id property="pid" column="pid" />
<result property="name" column="name" />
<collection property="mobiles" column="pid" ofType="wjf.Obj.Mobile">
<id property="id" column="mid" />
<result property="tel" column="tel" />
</collection>
</resultMap>

<select id="getPerson" parameterType="int" resultMap="resultMap">
select
p.pid,p.name ,m.mid ,m.tel
from person p ,mobile m where m.pid=p.pid
AND p.pid=#{id}
</select>
<select id="getALLPerson" resultMap="resultMap">
select
p.pid,p.name ,m.mid
,m.tel
from person p ,mobile m where m.pid=p.pid
</select>
</mapper>

package wjf.Obj;

import java.util.List;

public class Person {
private int pid;
private String name;
private List<Mobile> mobiles;
public List<Mobile> getMobiles() {
return mobiles;
}
public void setMobiles(List<Mobile> mobiles) {
this.mobiles = mobiles;
}
public int getId() {
return pid;
}
public void setId(int id) {
this.pid = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return "Person [id=" + pid + ", name=" + name + "]";
}
}

package wjf.Obj;

public class Mobile {
private int mid;
private String tel;
private Person person;
/**
* @return the mid
*/
public int getMid() {
return mid;
}
/**
* @param mid the mid to set
*/
public void setMid(int mid) {
this.mid = mid;
}
/**
* @return the person
*/
public Person getPerson() {
return person;
}
/**
* @param person the person to set
*/
public void setPerson(Person person) {
this.person = person;
}
public int getId() {
return mid;
}
public void setId(int id) {
this.mid = id;
}
public String getTel() {
return tel;
}
public void setTel(String tel) {
this.tel = tel;
}
@Override
public String toString() {
return "Mobile [id=" + mid + ", tel=" + tel + "]";
}
}

package wjf.dao;

import java.util.List;

import wjf.Obj.Mobile;

public interface MobileMapper {
public Mobile getMobile(int id);

public List<Mobile> getALLMobile();
}

package wjf.dao;

import java.util.List;
import wjf.Obj.Person;

public interface PersonMapper {
public Person getPerson(int id);

public List<Person> getALLPerson();
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<typeAliases>
<typeAlias alias="UserInfo" type="wjf.orm.UserInfo"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<!-- 配置数据库连接信息 -->
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/test" />
<property name="username" value="root" />
<property name="password" value="123" />
</dataSource>
</environment>
</environments>
<mappers>
<!-- <mapper resource="wjf/orm/userMapper.xml"/> -->
<!-- <mapper resource="wjf/orm/userMapper2.xml"/> -->
<mapper resource="wjf/config/MobileMapper.xml"/>
<mapper resource="wjf/config/PersonMapper.xml"/>
</mappers>
</configuration>

@Test
public void testRelation() {
SqlSessionFactory sqlSessionFactory = MybatisUtil
.getSqlsessionfactory();
SqlSession sqlSession = null;
sqlSession = sqlSessionFactory.openSession();
//        PersonMapper pmapper = sqlSession.getMapper(PersonMapper.class);
//        List<Person> plist = pmapper.getALLPerson();
//        System.out.println(plist.size());
//        Person p = pmapper.getPerson(1);
//        System.out.println(p.getMobiles().size());

MobileMapper mmapper = sqlSession.getMapper(MobileMapper.class);
List<Mobile> pMobile = mmapper.getALLMobile();
System.out.println(pMobile.size());
Mobile m = mmapper.getMobile(1);
System.out.println(m.getPerson().getName());
}

package wjf.orm;

import java.io.Reader;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

//工具类
public class MybatisUtil {
public static SqlSessionFactory sqlSessionFactory() {

String resource = "config.xml";// 获取mybatis-cofig.xml配置文件的路径
Reader reader = null;// 创建reader
try {
reader = Resources.getResourceAsReader(resource);// 获得reader
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
SqlSessionFactory SqlSessionFactory = new SqlSessionFactoryBuilder()
.build(reader);// 获得sqlsessionfactory
return SqlSessionFactory;
}

// 获取getter
public static SqlSessionFactory getSqlsessionfactory() {
return sqlSessionFactory();
}

}