java - 数据库decimal类型的怎么和String类型的比大小？

Question

String sql ="SELECT e.max,e.min,e.content,e.logo, sum(c.couponfee/100) FROM couponpublish c,couponpool s,hh_coupon_equivalent e  WHERE s.pubid=c.pubid AND s.status=3";
            List<Map> l = super.findListbySqlReturnMap(sql);
            for(int i=0;i<l.size();i++){
            double sum=(Double)list.get(i).get("sum(c.couponfee/100)");
            double max =(Double)l.get(i).get("max");
            double min = (Double)l.get(i).get("min");
                if(sum>min&&sum<max){
                    e.put("content",'2');
                }
            }
            
            max 和min是decimal类型，sum是string类型，他们3个怎么比大小