现在有很多电商平台，就拿这个来说吧。顾客跟订单的关系，一个顾客可以有多张订单，但是一个订单只能对应一个顾客。

　　一对多的顾客

<?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.zdp.domain.Person">

	<resultMap type="Person" id="personBean">

		<id column="personId" property="id"/>

		<result column="personName" property="name"/>

		<result column="personAddress" property="address"/>

		<result column="personTel" property="tel"/>

		<!-- 一对多的关系 -->

		<!-- property: 指的是集合属性的值, ofType：指的是集合中元素的类型 -->

		<collection property="orders" ofType="Order">

			<id column="orderId" property="id"/>

			<result column="orderNumber" property="number"/>

			<result column="orderPrice" property="price"/>

		</collection>

	</resultMap>

	<!-- 根据id查询Person, 关联将Orders查询出来 -->

	<select id="selectPersonById" parameterType="string" resultMap="personBean">

		select p.*, o.* from person p, orders o where p.personId  = o.pid and p.personId = #{id}

	</select>

</mapper>

多对一的订单

<?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.zdp.domain.Order">

	<resultMap type="Order" id="orderBean">

		<id column="orderId" property="id"/>

		<result column="orderNumber" property="number"/>

		<result column="orderPrice" property="price"/>

		<!-- 多对一的关系 -->

		<!-- property: 指的是属性的值, javaType：指的是属性的类型-->

		<association property="person" javaType="Person">

			<id column="personId" property="id"/>

			<result column="personName" property="name"/>

			<result column="personAddress" property="address"/>

			<result column="personTel" property="tel"/>

		</association>

	</resultMap>

	<!-- 根据id查询Order, 关联将Person查询出来 -->

	<select id="selectOrderById" parameterType="string" resultMap="orderBean">

		select p.*, o.* from person p, orders o where p.personId  = o.pid and o.orderId = #{id}

	</select>

</mapper>

总配置: sqlMapConfig.xml

<?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>
　　　　　／／这块儿做了别名的配置所以上面两个配置文件中可以使用Person和Order直接去代表类的全名

	<typeAliases>

	　　<typeAlias type="com.zdp.domain.Person" alias="Person"/>

        　　<typeAlias type="com.zdp.domain.Order" alias="Order"/>

	</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/test" />

				<property name="username" value="root" />

				<property name="password" value="root" />

			</dataSource>

		</environment>

	</environments>

	<mappers>

		<!-- 映射文件的位置 -->

		<mapper resource="com/zdp/domain/Person.xml" />

		<mapper resource="com/zdp/domain/Order.xml" />

	</mappers>

</configuration>