Mybatis 將數據庫中查出的記錄，一對多返回，即分組，然后返回每個組的所有數據

需求是一個pid下面會帶多個子id，前端傳一組pid集合，返回根據pid分組的所有子id及子id下的信息

  <select id="listBvsCustByParentMemberIds" resultMap="sellerCodeMap">
    select
    b.id as custMemberId,
    bvs.cust_code,
    mb.id as parentMemberId
    from member_base mb inner join bvs_parent_customer_info bvs on mb.seller_code = bvs.parent_code
    left join member_base  b on b.seller_code = bvs.cust_code
    where bvs.parent_code != bvs.cust_code and
    mb.id in
    <foreach collection="memberIds" item="memberId" open="(" separator="," close=")">
      #{memberId}
    </foreach>
  </select>

  <resultMap id="sellerCodeMap"
             type="com.yilihuo.cloud.service.user.dto.api.membercompany.ListBvsCustByParentMemberIdsResultDto">
    <result property="parentMemberId" column="parentMemberId"/>
    <collection property="childMemberInfos" ofType="com.yilihuo.cloud.service.user.dto.api.membercompany.ChildMemberInfoDto">
      <result property="custMemberId" column="custMemberId"></result>
      <result property="sellerCode" column="cust_code"></result>
    </collection>
  </resultMap>

 

通過<collection>標簽，將parentMemberId 相同的記錄存到ChildMemberInfoDto 里。然后返回，不需要其它邏輯.在一個就是需要

resultMap="sellerCodeMap"> 這個標簽，將數據庫查詢的記錄與出參返回值進行一個映射。

 

 出參樣式