1.表单按照字段合计
需要实现：
这里汇总的是整个表单中每一列的值，而不是每页的值。

实现：
在controller中加入：

@ResponseBody
    @PostMapping("/condition/list")
    public TableDataInfo fun2(ConditionDeploymentUnit conditionDeploymentUnit) {
        ConditionDeploymentUnit heji2 = conditionDeploymentUnitService.heji2();
        heji2.setIsDelete("汇总");
        startPage();
        List<ConditionDeploymentUnit> list = conditionDeploymentUnitService.selectConditionDeploymentUnitList(conditionDeploymentUnit);

        //按照轮次排序,但是只能在页面中排序
//        list = list.stream().sorted(Comparator.comparing(ConditionDeploymentUnit::getRounds))
//                .collect(Collectors.toList());

        list.add(heji2);
        return getDataTable(list);
    }

在mapper.xml文件中需要添加：

<select id="heji2" resultType="com.ruoyi.system.domain.ConditionDeploymentUnit" resultMap="ConditionDeploymentUnitResult">
        select sum(num_tier) as num_tier,
               ...
               sum(people_clue_register) as people_clue_register
        from condition_deployment_unit
    </select>

同时也需要在service，mapper中添加方法。

2.按照某个字段排序
需要在前端页面中加入如下两行，则是按照rounds字段升序排序，排序不会被分页结果影响