From aacab2d6c6f0260784167fb3ac2e666a87305380 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=BE=90=E6=B0=B8=E6=B7=B3?= <2678158018@qq.com> Date: Mon, 23 Oct 2023 21:22:19 +0800 Subject: [PATCH] =?UTF-8?q?=E7=AC=AC=E5=8D=81=E5=85=AB=E6=AC=A1=E4=BD=9C?= =?UTF-8?q?=E4=B8=9A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../20231020\344\275\234\344\270\232.md" | 255 ++++++++++++++++++ 1 file changed, 255 insertions(+) create mode 100644 "18 \345\276\220\346\260\270\346\267\263/20231020\344\275\234\344\270\232.md" diff --git "a/18 \345\276\220\346\260\270\346\267\263/20231020\344\275\234\344\270\232.md" "b/18 \345\276\220\346\260\270\346\267\263/20231020\344\275\234\344\270\232.md" new file mode 100644 index 0000000..75858b1 --- /dev/null +++ "b/18 \345\276\220\346\260\270\346\267\263/20231020\344\275\234\344\270\232.md" @@ -0,0 +1,255 @@ +```mysql +create database oooo charset utf8; +use oooo; +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 +select a.student_id,student_name,gender,birthday from student , +(SELECT * from score where course_id=1) a, +(select * from score where course_id=2) b +where student.student_id=a.student_id and student.student_id=b.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 * from student where student.student_id in (select student_id from score where course_id=1) and student.student_id in (select student_id from score where 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 where student.student_id in (select student_id from score where course_id=1) and student.student_id not in (select student_id from score 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 where student.student_id not in (select student_id from score where course_id=1) and student.student_id in (select student_id from score where course_id=2); +-- 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 student.student_id,student_name,avg(score) 平均成绩 from student,score where student.student_id=score.student_id group by student.student_id having 平均成绩>=60; +-- 6. 查询在成绩表存在成绩的学生信息 +select * from student where student_id in (select student_id from score); +-- 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 student.student_id,student_name,sum(course_id),sum(score) from student,score where score.student_id=student.student_id group by student.student_id; +-- 8. 查询「李」姓老师的数量 +select * from teacher where teacher.teacher_name like '李%'; +-- 9. 查询学过「李白」老师授课的同学的信息 +select * from student,score,course,teacher where student.student_id=score.student_id and score.course_id=course.course_id and course.teacher_id=teacher.teacher_id and teacher_name='李白'; +-- 10. 查询没有学全所有课程的同学的信息 +select * from student where student_id not in +(select student_id from score where course_id='1') + and + student_id not in +(select student_id from score where course_id='2') +and +student_id +not in +(select student_id from score where course_id='3') +-- 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 student.student_id,student_name,birthday,gender from student inner join score on student.student_id=score.student_id where course_id in (select course_id from score where student_id=1) and student.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 * + FROM student + WHERE student_id IN( + SELECT student_id + FROM score + GROUP BY student_id + HAVING count(course_id)=(SELECT COUNT(course_id) FROM score WHERE student_id=1 ) + AND student_id NOT IN( + SELECT DISTINCT student_id FROM score + WHERE course_id NOT IN (SELECT course_id FROM score WHERE student_id=1 )) + AND 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 a,score b,course c,teacher d where a.student_id=b.student_id and b.course_id=c.course_id and c.teacher_id=d.teacher_id and 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 stu.`student_id`, `student_name`, AVG(`score`) 平均成绩 +FROM `student` AS stu +RIGHT JOIN `score` AS sc +ON stu.`student_id` = sc.`student_id` +WHERE stu.`student_id` IN ( + -- 查询出两门以上不及格同学的学号 + SELECT `student_id` + FROM `score` + WHERE `score` < 60 + GROUP BY `student_id` + HAVING COUNT(`course_id`) >= 2) +GROUP BY stu.`student_id`; +-- 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,score where student.student_id=score.student_id and score<60 order by score desc; +-- -- 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 student_name,student.student_id,avg(score) 平均成绩 from student,score where student.student_id=score.student_id GROUP BY score.student_id order by 平均成绩 desc; +SELECT `student_name`, `score`, 平均成绩 +FROM `student` AS stu +RIGHT JOIN `score` AS sc +ON stu.`student_id` = sc.`student_id` +LEFT JOIN ( + SELECT `student_id`, AVG(`score`) 平均成绩 + FROM `score` + GROUP BY `student_id`) AS avg_sc +ON stu.`student_id` = avg_sc.`student_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 score.course_id,course_name,max(score) from student,score,course where student.student_id=score.student_id and score.course_id=course.course_id group by 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 * from score; +SELECT + score.course_id AS 课程ID, + course.course_name AS 课程name, + MAX(score.score) AS 最高分, + MIN(score.score) AS 最低分, + ROUND(AVG(score.score), 2) AS 平均分, + (SELECT ROUND(100*(SUM(CASE WHEN score.score >=90 THEN 1 ELSE 0 END)/SUM(CASE WHEN score.score THEN 1 ELSE 0 END)),2)) AS 优秀率, + (SELECT ROUND(100*(SUM(CASE WHEN score.score >=80 AND score.score < 90 THEN 1 ELSE 0 END)/SUM(CASE WHEN score.score THEN 1 ELSE 0 END)),2)) AS 优良率, + (SELECT ROUND(100*(SUM(CASE WHEN score.score >=70 AND score.score < 80 THEN 1 ELSE 0 END)/SUM(CASE WHEN score.score THEN 1 ELSE 0 END)),2)) AS 中等率, + (SELECT ROUND(100*(SUM(CASE WHEN score.score >=60 THEN 1 ELSE 0 END)/SUM(CASE WHEN score.score THEN 1 ELSE 0 END)),2)) AS 及格率 +FROM + score +LEFT JOIN course ON course.course_id = score.course_id +GROUP BY + score.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_id,score,rank() over (partition by course_id order by score) from score; +-- 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_id,score,row_number() over (partition by course_id order by score) from score; +-- 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 a.student_id,rank() over (order by a.score desc) 排名 ,a.score from (select student_id,sum(score) score from score group by student_id) 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 a.student_id,dense_rank() over (order by a.score desc) 排名 ,a.score from (select student_id,sum(score) score from score group by student_id) 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 c.course_id,c.course_name + ,((select count(*) from score sc where sc.course_id=c.course_id and sc.score<=100 and sc.score>80)/(select count(*) from score sc where sc.course_id=c.course_id )) "100-85" + ,((select count(*) from score sc where sc.course_id=c.course_id and sc.score<=85 and sc.score>70)/(select count(*) from score sc where sc.course_id=c.course_id )) "85-70" + ,((select count(*) from score sc where sc.course_id=c.course_id and sc.score<=70 and sc.score>60)/(select count(*) from score sc where sc.course_id=c.course_id )) "70-60" + ,((select count(*) from score sc where sc.course_id=c.course_id and sc.score<=60 and sc.score>=0)/(select count(*) from score sc where sc.course_id=c.course_id )) "60-0" + from course c order by c.course_id; +-- 24. 查询各科成绩前三名的记录 + select * from + (select student_id,score,rank() over (partition by course_id order by score desc) ranks from score) s + where ranks<4; +-- 25. 查询每门课程被选修的学生数 + select distinct s.course_id,c.course_name,count(s.student_id) over (partition by s.course_id) 学生数 from score s left join course c on s.course_id=c.course_id; +-- 26. 查询出只选修两门课程的学生学号和姓名 + select s.student_name 姓名,a.学号 from (select distinct student_id 学号,count(course_id) over (partition by student_id) 选修数 from score) a left join student s on a.`学号`=s.student_id where 选修数=2; +-- 27. 查询男生、女生人数 + select gender,count(student_id) 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 student_name from student group by student_name having count(student_id)>1; +-- 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_id,avg(score) from score group by course_id order by avg(score) desc,course_id asc; +-- 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 s.student_id,s.student_name,a.`平均成绩` from student s right join (select student_id,avg(score) 平均成绩 from score group by student_id having avg(score)>=85) a on s.student_id=a.student_id; +-- 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 right join score on student.student_id=score.student_id left join course on score.course_id=course.course_id 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 s2.student_name,s1.* from score s1 right join student s2 on s1.student_id=s2.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 s1.student_name,c.course_name,s2.score from student s1 right join score s2 on s1.student_id=s2.student_id left join course c on s2.course_id=c.course_id where score>70; +-- 36. 查询不及格的课程 + select distinct c.course_name from score s2 left join course c on s2.course_id=c.course_id where score<60; +-- 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 s1.student_id,s2.student_name from score s1,student s2 where course_id=1 and score>80 and s1.student_id=s2.student_id; +-- 38. 求每门课程的学生人数 + select distinct course_id,count(student_id) over (partition by course_id) from score; +-- 39. 成绩不重复，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 + +-- 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 + +-- 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 distinct s1.* from score s1,score s2 where s1.score=s2.score and s1.course_id!=s2.course_id; +-- 42. 查询每门功成绩最好的前两名 + select * from + (select student_id,score,rank() over (partition by course_id order by score desc) ranks from score) s + where ranks<=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_id,count(student_id) from score group by course_id having count(student_id)>5; +-- 44. 检索至少选修两门课程的学生学号 + 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 s2.* from score s1 right join student s2 on s1.student_id=s2.student_id group by student_id having count(course_id)>=(select count(course_id) 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 birthday,(date_format(now(),'%y') - date_format(birthday,'%y') - + (case when date_format(now(),'%m%d') > date_format(birthday,'%m%d') then 0 else 1 end)) as age + from student; +-- 48. 查询本周过生日的学生 + select * from student where day(birthday) between 16 and 22 and month(birthday)=month(now()); +-- 49. 查询下周过生日的学生 + select * from student where day(birthday) between 23 and 29 and month(birthday)=month(now()); +-- 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