resultMap标签中里的collection标签详解

package com.xyj.entity;
import java.util.List;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Employee {
	private int eid;
	private String ename;
	private String epwd;
	private String address;
	private String tel;
	private List<Sport> sports;//职员所参加的所有运动项目
}

package com.xyj.entity;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Sport {
    private int sportId;
    private String sportName;
    private String sportScore;
}

List<Employee> findSportsInfoByEmpId(@Param("eid")Integer id);

<select id="findSportsInfoByEmpId" resultMap="empmap">
        select e.*,s.*
        from employee as e,sport as s
        where e.eid=s.eid
        and e.eid=#{eid}
    </select>
    
    <resultMap type="Employee" id="empmap">
        <id property="eid" column="eid"/>
        <result property="ename" column="ename"/>
        <result property="epwd" column="epwd"/>
        <result property="address" column="address"/>
        <result property="tel" column="tel"/>
        <!-- collection描述一对多的关系，ofType是集合所包含的类型，可以写完整Java类名或别名  -->
        <collection property="sports" ofType="Sport">
            <id property="sportId" column="sportid"/>
            <result property="sportName" column="sportname"/>
            <result property="sportScore" column="sportscore"/>
        </collection>
    </resultMap>

@org.junit.Test
    public void test() {
        sqlSession session = mybatisUtils.getSqlSession();
        EmpDao ed = session.getMapper(EmpDao.class);
        List<Employee> list = ed.findSportsInfoByEmpId(1);
        for (Employee emp : list) {
            for (Sport e : emp.getSports()) {
                System.out.println(e);
            }
        }
    }

<select id="findSportsInfoByEmpId" resultMap="empmap">
		select e.*,s.*
		from employee as e,sport as s
		where e.eid=s.eid
		and e.eid=#{eid}
	</select>
	
	<resultMap type="Employee" id="empmap">
		<id property="eid" column="eid"/>
		<result property="ename" column="ename"/>
		<result property="epwd" column="epwd"/>
		<result property="address" column="address"/>
		<result property="tel" column="tel"/>
		<collection property="sports" ofType="Sport" resultMap="sportmap"></collection>
	</resultMap>
	
	<resultMap type="Sport" id="sportmap">
		<id property="sportId" column="sportid"/>
		<result property="sportName" column="sportname"/>
		<result property="sportScore" column="sportscore"/>
	</resultMap>

<result column="name" property="name"/>
<!--
collection定义一个子集合对象返回
ofType:指定集合里面元素的类型
property属性设置集合的属性名
-->
<collection property="passengers" ofType="Passenger">
<!--
id指的是主键,
column是数据库中的列,可以是别名
property映射的是实体类中的属性
result是普通列(非主键)
-->
<id column="pid" property="id"/>
<result column="pname" property="name"/>
</collection>
</resultMap>