Mybatis 查询结果是Map，Map中有List

结果集： 

  <resultMap id="groupMap" type="HashMap">
    <result column="code" jdbcType="VARCHAR" property="code"/>
    <collection property="roles" column="code" select="listChild"/>
  </resultMap>

sql: 

  <select id="listAndGroupByCode" resultMap="groupMap">
    SELECT code FROM bee_role
    where 1=1
    <if test="code !=null and code !=''">
      and code = #{code}
    </if>
    GROUP BY code
  </select>

  <select id="listChild" resultType="map">
    SELECT id,code,name
    FROM bee_role
    where 1=1
    and code = #{code}
  </select>

查询结果：