统计列出矩阵类型各分数段人数

Posted 2020-08-21 shrewdness

SQL查询

统计列出矩阵类型各分数段人数，横轴为分数段[100-85]、[85-70]、[70-60]、[<60]，纵轴为课程号、课程名称（提示使用case when句式）

SELECT SC.COURSE_NO,
        C.COURSE_NAME,
        SUM(CASE
              WHEN SC.CORE BETWEEN 85 AND 100 THEN
               1
              ELSE
               0
            END) AS "[100-85]",
        SUM(CASE
              WHEN SC.CORE BETWEEN 70 AND 85 THEN
               1
              ELSE
               0
            END) AS "[85-70]",
        SUM(CASE
              WHEN SC.CORE BETWEEN 60 AND 70 THEN
               1
              ELSE
               0
            END) AS "[70-60]",
        SUM(CASE
              WHEN SC.CORE < 60 then
               1
              ELSE
               0
            END) AS "[<60]"
   FROM HAND_STUDENT_CORE SC, 
        HAND_COURSE C
  WHERE SC.COURSE_NO = C.COURSE_NO
  GROUP BY SC.COURSE_NO, C.COURSE_NAME;