From 8f6b62a8ed75c9449abfbd0aba78add099db874f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E6=B2=88=E6=99=93=E7=90=B3?= <2115152499@qq.com> Date: Sun, 22 Oct 2023 21:55:29 +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 \344\275\234\344\270\232.md" | 251 ++++++++++++++++++ 1 file changed, 251 insertions(+) create mode 100644 "29 \346\262\210\346\231\223\347\220\263/20231020 \344\275\234\344\270\232.md" diff --git "a/29 \346\262\210\346\231\223\347\220\263/20231020 \344\275\234\344\270\232.md" "b/29 \346\262\210\346\231\223\347\220\263/20231020 \344\275\234\344\270\232.md" new file mode 100644 index 0000000..e981c57 --- /dev/null +++ "b/29 \346\262\210\346\231\223\347\220\263/20231020 \344\275\234\344\270\232.md" @@ -0,0 +1,251 @@ +```mysql +CREATE DATABASE school charset utf8; +use school; +# 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 +SELECT a.*,b.stu2 from +(SELECT student_id,score stu1 from score where course_id=1) a, +(SELECT student_id,score stu2 from score where course_id=2) b +where a.stu1>b.stu2 and a.student_id=b.student_id; + +-- 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_id in +(with a as(SELECT * from score where course_id=1), +b as(SELECT * from score where course_id=2) +SELECT a.student_id from a,b where a.student_id=b.student_id); +-- 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s示为 null ) +SELECT a.*,b.stu2 from +(SELECT student_id,score stu1 from score where course_id=1) a +left join +(SELECT student_id,score stu2 from score where course_id=2) b +on a.student_id=b.student_id; +-- 4. 查询不存在" 1 "课程但存在" 2 "课程的情况 +SELECT a.*,b.stu2 from +(SELECT student_id,score stu1 from score where course_id=1) a +right join +(SELECT student_id,score stu2 from score where course_id=2) b +on a.student_id=b.student_id where a.student_id is null; +-- 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 stu.student_id,student_name,a.b from student stu INNER JOIN (SELECT student_id,avg(score) as b from score GROUP BY student_id having avg(score)>=60) as a on stu.student_id=a.student_id; +-- 6. 查询在成绩表存在成绩的学生信息 +SELECT * from student s,score a where s.student_id=a.student_id and score is not null; +-- 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 s.student_id,s.student_name,count(course_id),sum(score) from student s left join score a on s.student_id=a.student_id GROUP BY s.student_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 + * +FROM + student s, + teacher t, + course c, + score sc + WHERE + s.student_id=sc.student_id + and t.teacher_id=c.teacher_id + and c.course_id=sc.course_id + and t.teacher_name='李白'; +-- 10. 查询没有学全所有课程的同学的信息 +SELECT s.* from student s,score sc where s.student_id=sc.student_id GROUP BY sc.student_id having count(sc.course_id)<(SELECT count(*) from course); +-- 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 * from student where student_id in(SELECT student_id from score where course_id in(SELECT course_id from score where 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 where course_id in(SELECT course_id from score where 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 + a.student_name +FROM + student a + LEFT JOIN ( + SELECT DISTINCT + student_id + FROM + score + WHERE + course_id IN ( + SELECT + course_id + FROM + course + WHERE + teacher_id = ( SELECT teacher_id FROM teacher WHERE teacher_name = '李白' ))) b ON a.student_id = b.student_id +WHERE b.student_id IS NULL; + +-- 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 student.student_id,student_name,b.avgs from student INNER JOIN (SELECT student_id,avg(score) as avgs from score where student_id in(SELECT student_id from score where score<60 GROUP BY student_id having count(*)>=2)GROUP BY student_id) b on student.student_id=b.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 s,score a where s.student_id=a.student_id and score in(SELECT score 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 * from score LEFT JOIN (SELECT student_id,avg(score) avgs from score GROUP BY student_id) a on score.student_id=a.student_id ORDER BY a.avgs desc; + +-- 17. 查询各科成绩最高分、最低分和平均分 +SELECT course_id,max(score),min(score),avg(score) from score 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 s.course_id,course_name,count(s.student_id) as '选修人数', max(s.score), min(score), avg(score), +CONCAT(sum(case when score >= 0 and score < 60 then 1 else 0 end) / COUNT(*)*100,'%') as'及格率', +CONCAT(sum(case when score >= 60 and score < 70 then 1 else 0 end) / COUNT(*)*100,'%') as '中等率', +CONCAT(sum(case when score >= 70 and score < 85 then 1 else 0 end) / COUNT(*)*100,'%') as '优良率', +CONCAT(sum(case when score >= 85 and score <= 100 then 1 else 0 end) / COUNT(*)*100,'%') as '优秀率' +FROM score s,course c where s.course_id=c.course_id GROUP BY c.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 * from (SELECT *,ROW_NUMBER() over(PARTITION by course_id ORDER BY score) a from score) b ORDER BY 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 * from (SELECT *,rank() over(PARTITION by course_id ORDER BY score) a from score) b ORDER BY 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 *,RANK() over(ORDER BY sumscore desc) as a from (SELECT student_id,sum(score) as sumscore from score GROUP BY student_id) as b; +-- 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 *,DENSE_RANK() over(ORDER BY sumscore desc) as a from (SELECT student_id,sum(score) as sumscore from score GROUP BY student_id) as b; + +-- 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,course_name, +CONCAT(sum(case when score >= 0 and score < 60 then 1 else 0 end) / COUNT(*)*100,'%') as'[0-60]', +CONCAT(sum(case when score >= 60 and score < 70 then 1 else 0 end) / COUNT(*)*100,'%') as '[60-70]', +CONCAT(sum(case when score >= 70 and score < 85 then 1 else 0 end) / COUNT(*)*100,'%') as '[70-85]', +CONCAT(sum(case when score >= 85 and score <= 100 then 1 else 0 end) / COUNT(*)*100,'%') as '[85-100]' +FROM score s,course c where s.course_id=c.course_id GROUP BY c.course_id; +-- 24. 查询各科成绩前三名的记录 +SELECT DISTINCT course_id,ROW_NUMBER() over(PARTITION by course_id ORDER BY score desc) from score; +-- 25. 查询每门课程被选修的学生数 +SELECT course_id,count(course_id)from score GROUP BY course_id; +-- 26. 查询出只选修两门课程的学生学号和姓名 +SELECT student.student_id,student.student_name from student INNER JOIN(SELECT student_id from score GROUP BY student_id having count(course_id)=2) b on student.student_id=b.student_id; +-- 27. 查询男生、女生人数 +SELECT gender,count(*) 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,count(*) from student GROUP BY student_name having count(*)>1; +-- 30. 查询 1990 年出生的学生名单 +SELECT * from student where birthday like '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 student.student_id,student.student_name,a.avgs from student INNER JOIN (SELECT student_id,avg(score) avgs from score GROUP BY student_id having avg(score)>=85) a on student.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 s,score a,course c where s.student_id=a.student_id and a.course_id=c.course_id and 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 s LEFT JOIN score a on s.student_id=a.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 s,score a,course c where s.student_id=a.student_id and a.course_id=c.course_id and score>70; +-- 36. 查询不及格的课程 +SELECT * from course c,score s where c.course_id=s.course_id and 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 s.student_id,s.student_name from student s INNER JOIN (SELECT student_id from score where course_id=1 and score<=80) a on s.student_id=a.student_id; +-- 38. 求每门课程的学生人数 +SELECT count(s.student_id) from student s,score a where s.student_id=a.student_id GROUP BY course_id; +-- 39. 成绩不重复，查询选修「李白」老师所授课程的学生中，成绩最高的学生信息及其成绩 +SELECT + max(sc.score) +FROM + student s, + teacher t, + course c, + score sc + WHERE + s.student_id=sc.student_id + and t.teacher_id=c.teacher_id + and c.course_id=sc.course_id + and t.teacher_name='李白'; +-- 40. 成绩有重复的情况下，查询选修「李白」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 s1.student_id,s1.course_id,s1.score 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 score a LEFT JOIN score b on a.course_id=b.course_id and a.score5; +-- 44. 检索至少选修两门课程的学生学号 +SELECT student_id 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 student_id 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()) from student; +-- 48. 查询本周过生日的学生 +SELECT * from student where WEEKOFYEAR(birthday)=WEEKOFYEAR(now()); +-- 49. 查询下周过生日的学生 +SELECT * from student where WEEKOFYEAR(birthday)=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