mybait一对多

<resultMap id="同意mapper文件唯一的标识" type="映射的pojo对象">
  <id column="表的主键字段对应别名" jdbcType="字段类型" property="映射pojo对象的主键属性" />
  <result column="表的一个字段的别名" jdbcType="字段类型" property="映射到pojo对象的对应属性"/>
   <!-- 一对一，代表这个对象里面的pojo对象-->
  <association property="pojo的一个对象属性" javaType="pojo关联的pojo对象">
    <id column="关联pojo对象对应表的主键字段" jdbcType="字段类型" property="关联pojo对象的主席属性"/>
    <result  column="任意表的字段" jdbcType="字段类型" property="关联pojo对象的属性"/>
  </association>
  <!-- 一对多，代表这个对象里面的集合pojo对象-->
  <collection property="pojo的集合属性" ofType="集合中的pojo对象">
    <id column="集合中pojo对象对应的表的主键字段" jdbcType="字段类型" property="集合中pojo对象的主键属性" />
    <result column="可以为任意表的字段" jdbcType="字段类型" property="集合中的pojo对象的属性" /> 
  </collection>
</resultMap>

例子2：

  <resultMap id="MultipleCompletionResp" type="com.jinmao.feign.multiple.response.MultipleCompletionResp">

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

        <result property="projectName" column="project_name"/>

        <result property="changeTypeName" column="arr_one"/>

        <result property="createName" column="create_name"/>

        <result property="approvalStatus" column="approval_status"/>

        <result property="createTime" column="create_time"/>

        <collection property="changNameList" ofType="java.lang.String"  >

         <result property="String" column="change_name" />

        </collection>

    </resultMap>

<select id="queryMultipleCompletionList" resultMap="MultipleCompletionResp">


        SELECT
        a.id , a.project_name , a.create_name ,a.create_time ,a.approval_status ,a.arr_one , b.change_name
        FROM `bs_multiple_completion` a

        left join bs_completion b on a.id = b.multiple_id
        where 1=1


        <if test="projectList!=null and projectList.size>0">
            and a.project_id in
            <foreach collection="projectList" item="projectId" close=")" open="(" separator=",">
                #{projectId}
            </foreach>
        </if>

        <if test="contractId!=null and contractId!=''">
            and a.contract_ids like concat('%',#{contractId},'%')
        </if>

        <if test="changeName!=null and changeName!=''">
            and a.change_name like concat('%',#{changeName},'%')
        </if>

        <if test="approvalStatusList!=null and approvalStatusList.size>0">
            and a.approval_status in
            <foreach collection="approvalStatusList" separator="," open="(" close=")" item="approvalStatus">
                #{approvalStatus}
            </foreach>
        </if>
        and a.arr_one = #{orderType} and a.arr_two = 'NORMAL' ;


    </select>