From da8fc6f8455895c44c26541c85f96b885146842d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E9=9F=A9=E6=96=87=E6=9D=B0?= <1820896556@qq.com> Date: Mon, 23 Oct 2023 21:19:41 +0800 Subject: [PATCH] =?UTF-8?q?=E7=BB=8F=E5=85=B850=E9=A2=98?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...\347\273\217\345\205\27050\351\242\230.md" | 372 ++++++++++++++++++ 1 file changed, 372 insertions(+) create mode 100644 "43 \351\237\251\346\226\207\346\235\260/\347\273\217\345\205\27050\351\242\230.md" diff --git "a/43 \351\237\251\346\226\207\346\235\260/\347\273\217\345\205\27050\351\242\230.md" "b/43 \351\237\251\346\226\207\346\235\260/\347\273\217\345\205\27050\351\242\230.md" new file mode 100644 index 0000000..1b7a013 --- /dev/null +++ "b/43 \351\237\251\346\226\207\346\235\260/\347\273\217\345\205\27050\351\242\230.md" @@ -0,0 +1,372 @@ +~~~mysq、 + +# 学生表 +create database test_1020 charset utf8; +use test_1020; +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); + +-- 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 + * +FROM + student +WHERE + student_id IN ( + SELECT + b.student_id + FROM + score a, + score b + WHERE + a.course_id = 1 + AND b.course_id = 2 + AND a.score > b.score + ); + +-- 2. 查询同时参与" 1 "课程和" 2 "课程考试的学生信息 +SELECT + s.* +FROM + student s, + score s1, + score s2 +WHERE + s.student_id = s1.student_id + AND s1.student_id = s2.student_id + AND s1.course_id = 1 + AND s2.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 score where course_id=1 or course_id=2; + +SELECT + st.*, + s.course_id +FROM + score s + LEFT JOIN student st ON s.student_id = st.student_id +WHERE + s.course_id NOT IN ( SELECT course_id FROM score WHERE score.course_id = 2 ) + AND s.course_id = 1; +-- 4. 查询不存在" 1 "课程但存在" 2 "课程的情况 + +SELECT + st.*, + s.course_id +FROM + score s + LEFT JOIN student st ON s.student_id = st.student_id +WHERE + s.course_id NOT IN ( SELECT course_id FROM score WHERE score.course_id = 1 ) + AND s.course_id = 2; + +select * 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 s.student_id,s.student_name,avg(score) from student s left join score sc on s.student_id=sc.student_id where sc.score>=(select avg(score) from score ) GROUP BY s.student_id; + +with + a as (select distinct student_id,avg(score) over(partition by student_id) as n from score s) + select a.student_id,stu.student_name,a.n from a,student stu where a.student_id=stu.student_id and a.n>60; + +-- 6. 查询在成绩表存在成绩的学生信息 +select distinct s.* from student s left join score sc on s.student_id=sc.student_id where sc.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(sc.course_id) 选课总数,sum(sc.score) 总成绩 from student s left join score sc on s.student_id=sc.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 + s.* +FROM + student s, + score sc, + course c, + teacher t +WHERE + s.student_id = sc.student_id + AND sc.course_id = c.course_id + AND c.teacher_id = t.teacher_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 * from student s where (select count(*) from score sc where s.student_id=sc.student_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 score where student_id= +(select student_id from student where student_id=1); + +SELECT + distinct(sc.student_id),s.* +FROM + ( SELECT course_id FROM score WHERE student_id = 1 ) AS a, + score sc, + student s +WHERE + a.course_id = sc.course_id + AND sc.student_id=s.student_id + and sc.student_id<>1 order by sc.student_id; +-- 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 + (select stu.student_id,count(course_id) 选课总数 + from student stu left join score sco on stu.student_id = sco.student_id group by stu.student_id) a + where a.选课总数 = (select count(*) 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 + distinct s.student_name +FROM + student s, + score sc, + course c, + teacher t +WHERE + s.student_id = sc.student_id + AND sc.course_id = c.course_id + AND c.teacher_id = t.teacher_id + and t.teacher_name not in(select t.teacher_name from teacher where t.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 s.student_id,student_name,平均成绩 from student s, + (select student_id,count(student_id) 不及格课程数,avg(score) 平均成绩 from score where score < 60 group by student_id ) a + where s.student_id = a.student_id and a.`不及格课程数` >= 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 s.* from student s left join score sc on s.student_id=sc.student_id where sc.course_id=1 and sc.score<60 order by sc.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_id,avg(score) as avg_score from score group by student_id order by avg_score desc; +-- 17. 查询各科成绩最高分、最低分和平均分 +select max(score) 最高分,min(score) 最低分,avg(score) 平均分 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 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_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 * from student s where (select count(*) from score sc where s.student_id=sc.student_id)<>(select count(*) from course); +-- 27. 查询男生、女生人数 +select gender,count(gender) 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,gender,count(*) from student group by student_name,gender having count(*)>=2; +-- 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 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 avg(score),s.student_id,st.student_name from score s left join student st on s.student_id=st.student_id group by s.student_id having avg(score)>=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 s.student_name,sc.score from student s,score sc,course c where s.student_id=sc.student_id and sc.course_id=c.course_id and c.course_name='数学' and sc.score in (select score from score where 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 + s.student_id, + s.student_name, + c.course_name, + sc.score +FROM + score sc + RIGHT JOIN student s ON sc.student_id = s.student_id + LEFT JOIN course c ON sc.course_id = c.course_id +GROUP BY + s.student_id, + s.student_name, + c.course_name, + sc.score; +-- 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 s.student_name,c.course_name,sc.score from student s,score sc,course c where s.student_id=sc.student_id and sc.course_id=c.course_id and sc.score>70; +-- 36. 查询不及格的课程 +select distinct c.course_name from score s,course c where s.course_id=c.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,sc.score from student s,score sc where s.student_id=sc.student_id and sc.course_id=1 and sc.score in (select score from score where score>=80); +-- 38. 求每门课程的学生人数 +select course_id,count(course_id) from score group by course_id; +-- 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 +SELECT + s.* ,sc.score +FROM + student s, + score sc, + course c, + teacher t +WHERE + s.student_id = sc.student_id + AND sc.course_id = c.course_id + AND c.teacher_id = t.teacher_id + AND sc.score IN ( + SELECT + max( score ) + FROM + score sc, + course c, + teacher t + WHERE + sc.course_id = c.course_id + AND c.teacher_id = t.teacher_id + AND t.teacher_name = '高斯' + ); +-- 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 + distinct s.* ,sc.score +FROM + student s, + score sc, + course c, + teacher t +WHERE + s.student_id = sc.student_id + AND sc.course_id = c.course_id + AND c.teacher_id = t.teacher_id + AND sc.score IN ( + SELECT + max( score ) + FROM + score sc, + course c, + teacher t + WHERE + sc.course_id = c.course_id + AND c.teacher_id = t.teacher_id + AND t.teacher_name = '高斯' + ); +-- 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_id,count(course_id) from score GROUP BY course_id having count(course_id)>=5; +-- 44. 检索至少选修两门课程的学生学号 +select s.student_id,count(sc.course_id) from student s,score sc where s.student_id=sc.student_id group by s.student_id having count(sc.course_id)>2; +-- 45. 查询选修了全部课程的学生信息 +select s.*, count(sc.student_id) from student s,score sc where s.student_id=sc.student_id group by sc.student_id having count(sc.student_id)=3; +-- 46. 查询各学生的年龄，只按年份来算 +select 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 student where weekday(student.birthday)=weekday(now()); +-- 49. 查询下周过生日的学生 +select * from student where weekday(student.birthday)=weekday(now())+1; +-- 50. 查询本月过生日的学生 +select * from student where month(student.birthday)=month(now()); +-- 51. 查询下月过生日的学生 +select * from student where month(birthday)=month(now())+1; + + +~~~ + -- Gitee