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    程序员石磊:mysql 按分数段,每个专业分数段统计人数

    作者:[db:作者] 时间:2021-07-04 18:45

    我的表结构

    student_info

    idnameprofessionscore
    id姓名分数专业

    按分数段统计

    400到500人数,300到400人数

    select
    count(case when score between 400 and 500 then 1 end) as 400500,
    count(case when score between 300 and 400 then 1 end) as 300400
    from student_info;
    

    在这里插入图片描述

    按分数段和专业统计

    400到500人数,300到400人数

    select
    count(case when score between 400 and 500 then 1 end) as 400500,
    count(case when score between 300 and 400 then 1 end) as 300400
    from student_info GROUP BY profession;
    

    在这里插入图片描述

    sql动态拼接生成

      int start = 200;
            int end = 700;
            int inter = 10;
            int count = (end-start)/inter;
            StringBuilder sqlBuilder = new StringBuilder();
            sqlBuilder.append("select ");
            for(int i =1;i<=count;i++){
                int next = start+inter-1;
                System.out.println(start + " \t" + next);
    
                sqlBuilder.append(" count(case when admission_score between ").append(start).append(" and ").append(next).append(" then 1 end) as ").append(start).append("到").append(next);
    
    
                if(i!=count){
                    sqlBuilder.append(", ");
                }
    
                start += inter;
            }
            sqlBuilder.append(" from z_student_info");
            System.out.println(sqlBuilder.toString());
    

    输出sql

    select  count(case when admission_score between 200 and 209 then 1 end) as 200209,  count(case when admission_score between 210 and 219 then 1 end) as 210219,  count(case when admission_score between 220 and 229 then 1 end) as 220229,  count(case when admission_score between 230 and 239 then 1 end) as 230239,  count(case when admission_score between 240 and 249 then 1 end) as 240249,  count(case when admission_score between 250 and 259 then 1 end) as 250259,  count(case when admission_score between 260 and 269 then 1 end) as 260269,  count(case when admission_score between 270 and 279 then 1 end) as 270279,  count(case when admission_score between 280 and 289 then 1 end) as 280289,  count(case when admission_score between 290 and 299 then 1 end) as 290299,  count(case when admission_score between 300 and 309 then 1 end) as 300309,  count(case when admission_score between 310 and 319 then 1 end) as 310319,  count(case when admission_score between 320 and 329 then 1 end) as 320329,  count(case when admission_score between 330 and 339 then 1 end) as 330339,  count(case when admission_score between 340 and 349 then 1 end) as 340349,  count(case when admission_score between 350 and 359 then 1 end) as 350359,  count(case when admission_score between 360 and 369 then 1 end) as 360369,  count(case when admission_score between 370 and 379 then 1 end) as 370379,  count(case when admission_score between 380 and 389 then 1 end) as 380389,  count(case when admission_score between 390 and 399 then 1 end) as 390399,  count(case when admission_score between 400 and 409 then 1 end) as 400409,  count(case when admission_score between 410 and 419 then 1 end) as 410419,  count(case when admission_score between 420 and 429 then 1 end) as 420429,  count(case when admission_score between 430 and 439 then 1 end) as 430439,  count(case when admission_score between 440 and 449 then 1 end) as 440449,  count(case when admission_score between 450 and 459 then 1 end) as 450459,  count(case when admission_score between 460 and 469 then 1 end) as 460469,  count(case when admission_score between 470 and 479 then 1 end) as 470479,  count(case when admission_score between 480 and 489 then 1 end) as 480489,  count(case when admission_score between 490 and 499 then 1 end) as 490499,  count(case when admission_score between 500 and 509 then 1 end) as 500509,  count(case when admission_score between 510 and 519 then 1 end) as 510519,  count(case when admission_score between 520 and 529 then 1 end) as 520529,  count(case
    
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