怎么将数据库的字段查出来后相加

Question

查出来后在前台怎么显示出来？

 /**
     * 查询全院数据
     */
    @RequestMapping(value = "/admin/allData.action")
    public String allData(){
        nursingQualityDataService
                .selectDataByYearAndQuarter(report_year, report_quarter);
        //ResultSet resultSet.
        /*int data = 0;
        List<BaseInfoData> baseInfoData = nursingQualityDataService
                .selectAllBaseInfoDataByYearAndQuarter(report_year, report_quarter);
        for(int i = 0; i < baseInfoData.size(); i++){
            data += baseInfoData.get(i).getOpenbeds_numbers();
        }
        model.addAttribute("baseInfoData",data);*/
        return "admin";
    }

Answer 1

做个简单的。
两个数据表db1,db2
查询结果A是从数据表db1获取的：
select names, sale from db1
查询结果B是从数据表db2获取的：
select names, sale from db2
则查询结果C：

select names,sum(sale) as sale 
from 
(select names, sale  from db1
union 
select names, sale  from db2
)
group by names