mybatis一对多，多对一

package com.kerwin.mybatis.pojo;
import java.util.List;
public class Person {
private int id;
private String name;
private List<Orders> orderList;
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 List<Orders> getOrderList() {
return orderList;
}
public void setOrderList(List<Orders> orderList) {
this.orderList = orderList;
}
@Override
public String toString() {
return "Person [id=" + id + ", name=" + name + "]";
}
public Person() {
super();
// TODO Auto-generated constructor stub
}
public Person(int id, String name, List<Orders> orderList) {
super();
this.id = id;
this.name = name;
this.orderList = orderList;
}
}

package com.kerwin.mybatis.pojo;

public class Orders {
private int id;
private double price;
private Person person;
public Person getPerson() {
return person;
}

public void setPerson(Person person) {
this.person = person;
}

public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

public double getPrice() {
return price;
}

public void setPrice(double price) {
this.price = price;
}

@Override
public String toString() {
return "Orders [id=" + id + ", price=" + price + "]";
}

public Orders() {
super();
// TODO Auto-generated constructor stub
}

}

<?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.kerwin.mybatis.pojo.Person">
<resultMap type="com.kerwin.mybatis.pojo.Person" id="personreSultMap">
<id column="p_id" property="id"/>
<result column="name" property="name"/>
<collection property="orderList" ofType="com.kerwin.mybatis.pojo.Orders" column="pid">
<id column="o_id" property="id"/>
<result column="price" property="price"/>
</collection>
</resultMap>
<select id="selectPersonFetchOrder" parameterType="int" resultMap="personreSultMap" >
select p.*,o.* from person p,orders o where o.pid=p.p_id and p.p_id=#{id}
</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="com.kerwin.mybatis.pojo.Orders">
<resultMap type="com.kerwin.mybatis.pojo.Orders" id="OrdersResultMap">
<id column="o_id" property="id"/>
<result column="price" property="price"/>
<association property="person" javaType="com.kerwin.mybatis.pojo.Person">
<id column="p_id" property="id"/>
<result column="name" property="name"/>
</association>
</resultMap>

<select id="selectOrdersFetchPerson" resultMap="OrdersResultMap">
select p.*,o.* from person p,orders o where o.pid=p.p_id and o.o_id=#{id}
</select>

</mapper>

<?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 type="com.kerwin.mybatis.pojo.Author" alias="Author"/>
</typeAliases>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="com/kerwin/mybatis/pojo/AuthorMapper.xml"/>
<mapper resource="com/kerwin/mybatis/pojo/PostMapper.xml"/>
<mapper resource="com/kerwin/mybatis/pojo/PersonMapper.xml"/>
<mapper resource="com/kerwin/mybatis/pojo/OrdersMapper.xml"/>
</mappers>
</configuration>