建表语句点击详见

– 统计各科成绩各分数段人数:课程编号,课程名称,[100-85],[85-70],[70-60],[0-60]及所占百分比


SELECT c.c_id,c.c_name 
,((SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id AND sc.s_score<=100 AND sc.s_score>80)/(SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id )) "100-85"
,((SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id AND sc.s_score<=85 AND sc.s_score>70)/(SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id )) "85-70"
,((SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id AND sc.s_score<=70 AND sc.s_score>60)/(SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id )) "70-60"
,((SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id AND sc.s_score<=60 AND sc.s_score>=0)/(SELECT COUNT(1) FROM score sc WHERE sc.c_id=c.c_id )) "60-0"
FROM course c ORDER BY c.c_id


Logo

基于 Vue 的企业级 UI 组件库和中后台系统解决方案,为数万开发者服务。

更多推荐