public class ResultIndustry {
  private String industryFirst;//一级行业
 private List<String> industrySecondList;//二级行业

<select id="getResultIndustryList" resultMap="resultIndustryMap">
  SELECT DISTINCT industry_first,industry_second
  FROM results
  WHERE industry_second IS NOT NULL
  AND industry_second != ""
 </select>
 <resultMap id="resultIndustryMap" type="com.gy_resc.common.bean.ResultIndustry">
  <result property="industryFirst" column="industry_first" jdbcType="VARCHAR"/>
  <collection property="industrySecondList" ofType="java.lang.String">
   <result property="industrySecond" column="industry_second" jdbcType="VARCHAR"/>
  </collection>
 </resultMap>