From 019f18464e2eae235002c1dae2046102922431a4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E8=B0=A2=E9=93=96=E6=B5=A9?= <1136734375@qq.com> Date: Tue, 24 Oct 2023 00:47:24 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BD=9C=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../20231020.md" | 97 +++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 "05 \350\260\242\351\223\226\346\265\251/20231020.md" diff --git "a/05 \350\260\242\351\223\226\346\265\251/20231020.md" "b/05 \350\260\242\351\223\226\346\265\251/20231020.md" new file mode 100644 index 0000000..74e722b --- /dev/null +++ "b/05 \350\260\242\351\223\226\346\265\251/20231020.md" @@ -0,0 +1,97 @@ +~~~mysql +# 学生表 +CREATE TABLE IF NOT EXISTS `student`( + `student_id` INT(10) NOT NULL AUTO_INCREMENT COMMENT '学号', + `student_name` VARCHAR(10) NOT NULL DEFAULT '匿名' COMMENT '姓名', + `birthday` DATETIME NOT NULL COMMENT '出生日期', + `gender` VARCHAR(10) NOT NULL DEFAULT '男' COMMENT '性别', + PRIMARY KEY(`student_id`) +)ENGINE=INNODB CHARSET=utf8; + +INSERT INTO `student` VALUES +(1 , '赵雷' , '1990-01-01' , '男'), +(2 , '钱电' , '1990-12-21' , '男'), +(3 , '孙风' , '1990-12-20' , '男'), +(4 , '李云' , '1990-12-06' , '男'), +(5 , '周梅' , '1991-12-01' , '女'), +(6 , '吴兰' , '1992-01-01' , '女'), +(7 , '郑竹' , '1989-01-01' , '女'), +(8 , '张三' , '2017-12-20' , '女'), +(9 , '李四' , '2017-12-25' , '女'), +(10 , '李四' , '2012-06-06' , '女'), +(11 , '赵六' , '2013-06-13' , '女'), +(12 , '孙七' , '2014-06-01' , '女'); +-- 课程表 +CREATE TABLE IF NOT EXISTS `course`( + `course_id` INT(4) NOT NULL AUTO_INCREMENT COMMENT '课程编号', + `course_name` VARCHAR(10) NOT NULL COMMENT '课程名', + `teacher_id` INT(10) NOT NULL COMMENT '任课教师工号', + PRIMARY KEY(`course_id`) +)ENGINE=INNODB CHARSET=utf8; + +INSERT INTO `course` VALUES +(1, '语文', 2), +(2, '数学', 1), +(3, '英语', 3); +# 教师表 +CREATE TABLE IF NOT EXISTS `teacher`( + `teacher_id` INT(10) NOT NULL AUTO_INCREMENT COMMENT '教师工号', + `teacher_name` VARCHAR(10) NOT NULL DEFAULT '匿名' COMMENT '教师姓名', + PRIMARY KEY(`teacher_id`) +)ENGINE=INNODB CHARSET=utf8; + +INSERT INTO `teacher` VALUES +(1, '高斯'), +(2, '李白'), +(3, 'Trump'); + +-- 成绩表 +CREATE TABLE IF NOT EXISTS `score`( + `student_id` INT(10) NOT NULL COMMENT '学号', + `course_id` INT(4) NOT NULL COMMENT '课程编号', + `score` DECIMAL(18,1) COMMENT '成绩', + KEY(`course_id`) +)ENGINE=INNODB CHARSET=utf8; + +INSERT INTO `score` VALUES +(1 , 1 , 80), +(1 , 2 , 90), +(1 , 3 , 99), +(2 , 1 , 70), +(2 , 2 , 60), +(2 , 3 , 80), +(3 , 1 , 80), +(3 , 2 , 80), +(3 , 3 , 80), +(4 , 1 , 50), +(4 , 2 , 30), +(4 , 3 , 20), +(5 , 1 , 76), +(5 , 2 , 87), +(6 , 1 , 31), +(6 , 3 , 34), +(7 , 2 , 89), +(7 , 3 , 98); + +题目： +-- 1. 查询" 1 "课程比" 2 "课程成绩高的学生的信息（学号、姓名、性别、出生日期）及课程分数 with a as (select student_id,score from score where course_id=2), b as (select student_id,score from score where course_id=1), c as (select * from student) select c.student_id,student_name,gender,birthday from a,b,c where a.student_id=b.student_id and b.student_id=c.student_id and b.score>a.score; -- 2. 查询同时参与" 1 "课程和" 2 "课程考试的学生信息 select t.* from score c,student t,score s where c.student_id=t.student_id and t.student_id=s.student_id and c.course_id = 1 and s.course_id = 2; -- 3. 查询存在" 1 "课程但可能不存在" 2 "课程的情况(不存在时显示为 null ) select * from student t right join score c on t.student_id=c.student_id where t.student_id not in(select t.student_id from student t right join score c on t.student_id=c.student_id where course_id =2); -- 4. 查询不存在" 1 "课程但存在" 2 "课程的情况 select * from student t right join score c on t.student_id=c.student_id where t.student_id not in(select t.student_id from student t right join score c on t.student_id=c.student_id where course_id =1); -- 5. 查询平均成绩大于等于 60 分的同学的学生编号、姓名和平均成绩 select distinct t.student_id,student_name,avg(score) a from student t,score c where t.student_id=c.student_id group by t.student_id having a>=60; -- 6. 查询在成绩表存在成绩的学生信息 select distinct t.* from score c,student t where c.student_id=t.student_id; -- 7. 查询所有同学的学生编号、学生姓名、选课总数、所有课程的总成绩(没成绩的显示为 null ) select * from student t left join score c on t.student_id=c.student_id left join course o on c.course_id=o.course_id; -- 8. 查询「李」姓老师的数量 select count() from teacher where teacher_name like '李%'; -- 9. 查询学过「李白」老师授课的同学的信息 select t. from teacher a left join course o on a.teacher_id=o.teacher_id left join score c on o.course_id=c.course_id left join student t on c.student_id=t.student_id where teacher_name = '李白'; -- 10. 查询没有学全所有课程的同学的信息 select * from student t left join score c on t.student_id=c.student_id left join course o on c.course_id=o.course_id where course_name is null; -- 11. 查询至少有一门课与学号为" 1 "的同学所学相同的同学的信息 select distinct t.student_id,student_name,birthday,gender from student t,score c where t.student_id=c.student_id and course_id in (select course_id from student t,score c where t.student_id=c.student_id and t.student_id=1); -- 12. 查询和" 1 "号的同学学习的课程完全相同的其他同学的信息 select distinct t.student_id,student_name,gender,birthday from student t,score c where t.student_id=c.student_id group by t.student_id having count(course_id) = (select count() from student t,score c where t.student_id=c.student_id and t.student_id=1); -- 13. 查询没学过「李白」老师讲授的任一门课程的学生姓名 select * from student where student_name not in (select student_name from teacher a left join course o on a.teacher_id=o.teacher_id left join score c on o.course_id=c.course_id left join student t on c.student_id=t.student_id where teacher_name = '李白'); -- 14. 查询两门及其以上不及格课程的同学的学号，姓名及其平均成绩 select distinct t.student_id,student_name,avg(score) over(partition by student_name) from student t,score c where t.student_id=c.student_id and t.student_id in (select student_id from score where score < 60 GROUP BY student_id having count()>=2); -- 15. 检索" 1 "课程分数小于 60，按分数降序排列的学生信息 select * from student where student_id in (select student_id from score where course_id=1 and score<60); + +-- 16. 按平均成绩从高到低显示所有学生的所有课程的成绩以及平均成绩 select stu.student_name,course_name,score,avg(score) over(partition by stu.student_id) 平均成绩 from student stu left join score sco on stu.student_id = sco.student_id left join course c on sco.course_id = c.course_id order by 平均成绩 desc; -- 17. 查询各科成绩最高分、最低分和平均分 select course_name 学科,max(score) 最高分,min(score) 最低分,avg(score) 平均分 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id; -- 18. 以如下形式显示：课程 ID，课程 name，最高分，最低分，平均分，及格率，中等率，优良率，优秀率（及格为>=60，中等为：70-80，优良为：80-90，优秀为：>=90），要求输出课程号和选修人数，查询结果按人数降序排列，若人数相同，按课程号升序排列 select sco.course_id,course_name,max(score) 最高分,min(score) 最低分,avg(score) 平均分, count(score>=60 or null)/count(sco.course_id) 及格率, count(score>=70 or null)/count(sco.course_id) 中等率, count(score>=80 or null)/count(sco.course_id) 优良率, count(score>=90 or null)/count(sco.course_id) 优秀率, count(sco.course_id) 选修人数 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id order by 选修人数 desc,sco.course_id; -- 19. 按各科成绩进行排序，并显示排名，Score 重复时保留名次空缺 select student_id,course_name,score,row_number() over(partition by student_id order by score desc) 排名 from score sco left join course c on sco.course_id = c.course_id ; -- 20. 按各科成绩进行排序，并显示排名，Score 重复时合并名次 select student_id,course_name,score,dense_rank() over(partition by student_id order by score desc) 排名 from score sco left join course c on sco.course_id = c.course_id ; -- 21. 查询学生的总成绩，并进行排名，总分重复时保留名次空缺 select *,row_number() over(order by a.总分 desc) from (select stu.student_id,student_name, sum(score) 总分 from student stu left join score sco on stu.student_id = sco.student_id group by stu.student_id order by 总分 desc) a; -- 22. 查询学生的总成绩，并进行排名，总分重复时不保留名次空缺 select *,rank() over(order by a.总分 desc) from (select stu.student_id,student_name, sum(score) 总分 from student stu left join score sco on stu.student_id = sco.student_id group by stu.student_id order by 总分 desc) a; -- 23. 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]，[60-0] 及所占百分比 select sco.course_id,course_name, count(score<60 or null) [60-0]人数, count(score>=60 and score<=70 or null) [70-60]人数, count(score >70 and score <=85 or null) [85-70]人数, count(score>85 or null) [100-85]人数, concat(round(count(score<60 or null)/count(sco.course_id)*100,2),'%') [0-60]所占百分比, concat(round(count(score>=60 and score<=70 or null)/count(sco.course_id)*100,2),'%')[60-70]所占百分比, concat(round(count(score >70 and score <=85 or null)/count(sco.course_id)*100,2),'%') [70-85]所占百分比, concat(round(count(score>85 or null)/count(sco.course_id)*100,2),'%') [100-85]所占百分比 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id ; -- 24. 查询各科成绩前三名的记录 select * from (select student_id,course_name,score,row_number() over(partition by sco.course_id order by score desc) 排名 from score sco left join course c on sco.course_id = c.course_id) a where a.排名 < 4 -- 25. 查询每门课程被选修的学生数 select course_name,count(sco.student_id) 课程被选修的学生数 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id; -- 26. 查询出只选修两门课程的学生学号和姓名 select student_id,student_name from student where student_id in (select student_id from (select student_id,count(course_id) 选修课程数 from score group by student_id having 选修课程数 = 2) a); -- 27. 查询男生、女生人数 select gender,count(gender) 人数 from student group by gender; -- 28. 查询名字中含有「风」字的学生信息 select * from student where student_name like '%风%'; -- 29. 查询同名同性学生名单，并统计同名人数 select s1.student_name,count(s1.student_name) 同名人数 from student s1,student s2 where s1.student_name = s2.student_name and s1.gender = s2.gender and s1.student_id != s2.student_id group by s1.student_name; -- 30. 查询 1990 年出生的学生名单 select * from student where year(birthday) = 1990; -- 31. 查询每门课程的平均成绩，结果按平均成绩降序排列，平均成绩相同时，按课程编号升序排列 select course_name 课程名称,avg(score) 平均成绩 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id order by 平均成绩 desc ,sco.course_id -- 32. 查询平均成绩大于等于 85 的所有学生的学号、姓名和平均成绩 select stu.student_id,student_name,avg(score) 平均成绩 from student stu left join score sco on stu.student_id = sco.student_id group by stu.student_id having 平均成绩 >=85; -- 33. 查询课程名称为「数学」，且分数低于 60 的学生姓名和分数 select student_name,score from student stu left join score sco on stu.student_id = sco.student_id where course_id =(select course_id from course where course_name = '数学') and score < 60; -- 34. 查询所有学生的课程及分数情况（存在学生没成绩，没选课的情况） select * from student stu left join score sco on stu.student_id = sco.student_id -- 35. 查询任何一门课程成绩在 70 分以上的姓名、课程名称和分数 + +select student_name,course_name,score from student stu,score sco,course c , (select stu.student_id 编号, count(score > 70 or null) 大于70分的个数,count(score) 选修课程个数 from student stu right join score sco on stu.student_id = sco.student_id group by stu.student_id having 大于70分的个数 = 选修课程个数) a where stu.student_id = sco.student_id and sco.course_id = c.course_id and stu.student_id = a.编号 ; + +-- 36. 查询不及格的课程 + +其中有一个学生不及格？ +select course_name 不及格的课程 from course where course_id in (select distinct course_id from score where score < 60); + +该课目的平均成绩不及格？ +select course_name 不及格的课程 from course c, (select course_id,avg(score) 平均成绩 from score group by course_id having 平均成绩 < 60) a where c.course_id = a.course_id; -- 37. 查询课程编号为 1 且课程成绩在 80 分以上的学生的学号和姓名 select stu.student_id, student_name from student stu left join score sco on stu.student_id = sco.student_id where sco.course_id = 1 and score >=80; -- 38. 求每门课程的学生人数 select course_name 课程名称,count(sco.course_id) 学生人数 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id; -- 39. 成绩不重复，查询选修「高斯」老师所授课程的学生中，成绩最高的学生信息及其成绩 + +select stu.*,score from student stu left join score sco on stu.student_id = sco.student_id where sco.course_id = +(select course_id from course where teacher_id = (select teacher_id from teacher where teacher_name = '高斯')) order by score desc limit 0,1 + +-- 40. 成绩有重复的情况下，查询选修「张三」老师所授课程的学生中，成绩最高的学生信息及其成绩 select stu.,score from student stu left join score sco on stu.student_id = sco.student_id where sco.course_id = +(select course_id from course where teacher_id = (select teacher_id from teacher where teacher_name = '高斯')) order by score desc limit 0,1 -- 41. 查询不同课程成绩相同的学生的学生编号、课程编号、学生成绩 select stu.student_id,course_id,score from student stu left join score sco on stu.student_id = sco.student_id where stu.student_id in (select distinct s1.student_id from score s1,score s2 where s1.course_id != s2.course_id and s1.score = s2.score); -- 42. 查询每门功成绩最好的前两名 select * from (select student_id,course_name,score,row_number() over(partition by sco.course_id order by score desc) 排名 from score sco left join course c on sco.course_id = c.course_id ) a where a.排名 <=2 -- 43. 统计每门课程的学生选修人数（超过 5 人的课程才统计）。 select course_name 课程名称,count(sco.course_id) 学生人数 from score sco left join course c on sco.course_id = c.course_id group by sco.course_id having 学生人数 > 5; -- 44. 检索至少选修两门课程的学生学号 select * from student where student_id in ( select student_id from score group by student_id having count(course_id) >= 2); -- 45. 查询选修了全部课程的学生信息 select * from student where student_id in ( select student_id from score group by student_id having count(course_id) = (select count() from course)); -- 46. 查询各学生的年龄，只按年份来算 select student_name,year(now())-year(birthday) from student; -- 47. 按照出生日期来算，当前月日 < 出生年月的月日则，年龄减一 select student_name,timestampdiff(year,birthday,now()) 年龄 from student; -- 48. 查询本周过生日的学生 select * from (select *,concat_ws('-',year(now()),month(birthday),day(birthday)) 今年生日 from student) a where weekofyear(a.今年生日) <= weekofyear(now()) and weekofyear(a.今年生日) >= weekofyear(now())-7; -- 49. 查询下周过生日的学生 select * from (select *,concat_ws('-',year(now()),month(birthday),day(birthday)) 今年生日 from student) a where weekofyear(a.今年生日) >= weekofyear(now()) and weekofyear(a.今年生日) <= weekofyear(now())+1; -- 50. 查询本月过生日的学生 select * from student where month(birthday)=month(NOW()); -- 51. 查询下月过生日的学生 select * from student where month(birthday)=month(NOW())+1; +~~~ + -- Gitee