mybatis 聚合查询，统计不使用实体类映射的方法

以按月统计奖金发放金额为例：

1、mapper文件:

<select id="selectAction" parameterType="string" resultType="map">
    ${sql}
   </select>

2.接口：

public List<Map> selectAction(@Param("sql") String sql);

3.controller:

//按月统计奖金发放金额
    @RequestMapping("manage/selbydate")
    public String selbydate(HttpSession session,Model model) {
        Userinfo userinfo = (Userinfo)session.getAttribute("loginAdmin");
        String sql="SELECT SUM(bonus) jiangjin ,DATE_FORMAT(createtime, '%Y-%m') riqi FROM salary where xueyuan='"+userinfo.getMoney()+"'GROUP BY DATE_FORMAT(createtime, '%Y-%m')" ;
        List<Map> maps = salaryDao.selectAction(sql);
        model.addAttribute("maps", maps);
        return "manage/salaryinfo/salarysumList";

    }

4.前端页面:

 <table class="layui-table">
        <tbody>
        <tr class="layui-bg-blue">
             <th>时间</th>
             <th>总额</th>
        </tr>


    <c:forEach items="${maps}" var="v">
        <tr>
            <td>${v.riqi}</td>
            <td>${v.jiangjin}元</td>

          
        </tr>
    </c:forEach>


        </tbody>
    </table>

5.显示效果：