这里查询两个表的数据，全部返回

• 两个表返回数据用一个map接受

      <!-- 获取行政区划树包括城中村 -->
    <select id="findAreaVTreeById" resultMap="areaMap" parameterType="Long">
        SELECT a.`id`,a.`area_name`,a.`parent_id`,a.area_level,a.area_code  FROM pmi_area a where   a.db_status = 1 and a.id=#{id}
        union all
        SELECT v.id, v.`name` as area_name,a.id as parent_id,4 as area_level,v.village_code as area_code   from base_village v
        LEFT JOIN pmi_area a on v.street_code=a.area_code and a.db_status=1
        where v.db_status=1  and v.id=#{id}
    </select>