使用MyBatis返回其它类对象的字段处理

目录

• MyBatis返回其它类对象的字段处理
  • 需求
    • 此时两种处理方式
• MyBatis返回自定义字段接收
  • 1、有时候需要查询的返回的结果不是javaBean的属性
  • 2、DAO接口
  • 3、后台取值

SELECT
        *
FROM
sce_salegoods

SELECT
        g.*,u.nickname as nickname
FROM
sce_salegoods g
   LEFT JOIN sce_sale s ON s.id = g.sale_id
   LEFT JOIN sce_users u ON u.uid = s.user_id

@Override
public void findSaleGoodsByGoodsType(PageInfo pageInfo) {
   List<SaleGoods> saleGoodsList = saleGoodsMapper.findSaleGoodsByGoodsType(pageInfo);
   int count = saleGoodsMapper.findSaleGoodsByGoodsTypeCount(pageInfo); // 条数
   pageInfo.setRows(saleGoodsList); 
   pageInfo.setTotal(count);
   
}

<resultMap extends="BaseResultMap" id="BaseResultMapAndSaleAttr" type="com.newcsp.oracle.pojo.SaleGoods">
      <result column="ordersn" jdbcType="VARCHAR" property="ordersn" />
<!-- ofType：表示需要加进去的类  property：表示在被继承的类SaleGoods中加入userList这个字段 -->
<collection ofType="com.newcsp.oracle.pojo.User" property="userList">
    <result column="cvisible" jdbcType="VARCHAR" property="cvisible" />
</collection>

<select id="statisticsByMonth" resultType="map">
   SELECT a.tallyTime,SUM(a.paid) sumPaid FROM(
  SELECT LOGIN_ID loginId,SUBSTR(TALLY_TIME,1,6) tallyTime,AMOUNT_PAID paid FROM tally) a 
  WHERE a.loginId=${loginId} AND a.tallyTime LIKE "${year}%"
  GROUP BY a.tallyTime
  ORDER BY a.tallyTime
  </select>

public List<Map<Object,Object>> statisticsByMonth(
                   @Param(value="loginId")Integer loginId,@Param(value="year")String year);

List<Map<Object,Object>> m = tallyDao.statisticsByMonth(loginId, year);
for(int i=0;i<m.size();i++){
   Map<Object,Object> got = m.get(i);//取出集合中的每一个map,map内容是月份-支出总金额的键值对
}