数据源准备:
# 学生表
create table student( sno varchar(10) primary key, #学号sname varchar(20), #姓名sage int(2), #年龄ssex varchar(5) #性别
); #教师表
create table teacher( tno varchar(10) primary key, #教师号tname varchar(20) #教师姓名
); #课程表
create table course( cno varchar(10), #课程号cname varchar(20), #课程名tno varchar(20), #教师号constraint pk_course primary key (cno,tno)
); #分数表
create table sc( sno varchar(10), #学号cno varchar(10), #课程号score DECIMAL(4,2), #分数constraint pk_sc primary key (sno,cno)
); 插入数据源
# 学生表
insert into student values ('s001','张三',23,'男');
insert into student values ('s002','李四',23,'男');
insert into student values ('s003','吴鹏',25,'男');
insert into student values ('s004','琴沁',20,'女');
insert into student values ('s005','王丽',20,'女');
insert into student values ('s006','李波',21,'男');
insert into student values ('s007','刘玉',21,'男');
insert into student values ('s008','萧蓉',21,'女');
insert into student values ('s009','陈晓',23,'女');
insert into student values ('s010','陈美',22,'女');
commit; #教师表
insert into teacher values ('t001', '刘阳');
insert into teacher values ('t002', '谌燕');
insert into teacher values ('t003', '胡明星');
commit;#课程表
insert into course values ('c001','J2SE','t002');
insert into course values ('c002','Java Web','t002');
insert into course values ('c003','SSH','t001');
insert into course values ('c004','Oracle','t001');
insert into course values ('c005','SQL SERVER 2005','t003');
insert into course values ('c006','C#','t003');
insert into course values ('c007','JavaScript','t002');
insert into course values ('c008','DIV+CSS','t001');
insert into course values ('c009','PHP','t003');
insert into course values ('c010','EJB3.0','t002');
commit; #分数表
insert into sc values ('s001','c001',78.9);
insert into sc values ('s002','c001',80.9);
insert into sc values ('s003','c001',81.9);
insert into sc values ('s004','c001',60.9);
insert into sc values ('s001','c002',82.9);
insert into sc values ('s002','c002',72.9);
insert into sc values ('s003','c002',81.9);
insert into sc values ('s001','c003','59');
commit;
接下来我们要完成哪些SQL操作呢?
16、向SC 表中插入一些记录,这些记录要求符合以下条件:没有上过编号“c002”课程的同学学号、“c002”号课的平均成绩;
17、查询各科成绩最高和最低的分:以如下形式显示:课程ID,最高分,最低分
18、按各科平均成绩从低到高和及格率的百分数从高到低顺序
19、查询不同老师所教不同课程平均分从高到低显示
20、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]
21、查询各科成绩前三名的记录:(不考虑成绩并列情况)
22、查询每门课程被选修的学生数
23、查询出只选修了一门课程的全部学生的学号和姓名
24、查询男生、女生人数
25、查询姓“张”的学生名单
26、查询同名同性学生名单,并统计同名人数
27、1981 年出生的学生名单(注:Student 表中Sage 列的类型是number)
28、查询每门课程的平均成绩,结果按平均成绩升序排列,平均成绩相同时,按课程号降序排列
29、查询平均成绩大于85 的所有学生的学号、姓名和平均成绩
30、查询课程名称为“数据库”,且分数低于60 的学生姓名和分数
31、查询所有学生的选课情况;
32、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;
33、查询不及格的课程,并按课程号从大到小排列
34、查询课程编号为c001 且课程成绩在80 分以上的学生的学号和姓名;
35、求选了课程的学生人数
36、查询选修“谌燕”老师所授课程的学生中,成绩最高的学生姓名及其成绩
37、查询各个课程及相应的选修人数
38、查询不同课程成绩相同的学生的学号、课程号、学生成绩
39、查询每门功课成绩最好的前两名
40、统计每门课程的学生选修人数(超过10人的课程才统计)。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
41、检索至少选修两门课程的学生学号
42、查询全部学生都选修的课程的课程号和课程名
43、查询没学过“谌燕”老师讲授的任一门课程的学生姓名
44、查询两门以上不及格课程的同学的学号及其平均成绩
45、检索“c004”课程分数小于60,按分数降序排列的同学学号
46、删除“s002”同学的“c001”课程的成绩
完成这46个SQL的学习与操作,对于职场中,数据库部分的操作就没有任何问题了,
当然不会写也没有关系,
我们借助于人工智能ChatGPT来帮助我们一起来完成学习SQL操作。
Prompt:
学生表 student 字段有 sno为学号,sname为姓名,sage为年龄,ssex为性别 教师表 teacher 字段有 tno为教师号,tname教师姓名 课程表 course 字段有 cno为课程号,cname为课程名,tno教师号 分数表 sc 字段有 sno为学号,cno 为课程号,score为分数 请写出SQL:向SC 表中插入一些记录,这些记录要求符合以下条件:没有上过编号“c002”课程的同学学号、“c002”号课的平均成绩
16、向SC 表中插入一些记录,这些记录要求符合以下条件:没有上过编号“c002”课程的同学学号、“c002”号课的平均成绩;
INSERT INTO sc (sno, cno, score)
SELECT s.sno, 'c002', AVG(sco.score)
FROM student s
LEFT JOIN sc sco ON s.sno = sco.sno
WHERE s.sno NOT IN (SELECT sno FROM sc WHERE cno = 'c002')
GROUP BY s.sno;
17、查询各科成绩最高和最低的分:以如下形式显示:课程ID,最高分,最低分
SELECT cno, MAX(score) AS max_score, MIN(score) AS min_score
FROM sc
GROUP BY cno;
18、按各科平均成绩从低到高和及格率的百分数从高到低顺序
SELECT c.cno, c.cname, AVG(s.score) AS average_score, SUM(CASE WHEN s.score >= 60 THEN 1 ELSE 0 END) / COUNT(*) * 100 AS pass_rate
FROM course c
LEFT JOIN sc s ON c.cno = s.cno
GROUP BY c.cno, c.cname
ORDER BY average_score ASC, pass_rate DESC;
19、查询不同老师所教不同课程平均分从高到低显示
SELECT t.tno, t.tname, c.cno, c.cname, ROUND(AVG(s.score), 2) AS average_score
FROM teacher t
INNER JOIN course c ON t.tno = c.tno
INNER JOIN sc s ON c.cno = s.cno
GROUP BY t.tno, t.tname, c.cno, c.cname
ORDER BY average_score DESC;
20、统计列印各科成绩,各分数段人数:课程ID,课程名称,[100-85],[85-70],[70-60],[ <60]
SELECT c.cno AS 课程ID, c.cname AS 课程名称,
SUM(CASE WHEN s.score BETWEEN 85 AND 100 THEN 1 ELSE 0 END) AS '[100-85]',
SUM(CASE WHEN s.score BETWEEN 70 AND 84 THEN 1 ELSE 0 END) AS '[85-70]',
SUM(CASE WHEN s.score BETWEEN 60 AND 69 THEN 1 ELSE 0 END) AS '[70-60]',
SUM(CASE WHEN s.score < 60 THEN 1 ELSE 0 END) AS '[ <60]'
FROM course c
INNER JOIN sc s ON c.cno = s.cno
GROUP BY c.cno, c.cname;
21、查询各科成绩前三名的记录:(不考虑成绩并列情况)
WITH RankedScores AS (SELECT c.cname AS 课程名称, s.sno AS 学号, s.score AS 分数,ROW_NUMBER() OVER(PARTITION BY c.cno ORDER BY s.score DESC) AS 排名FROM course cINNER JOIN sc s ON c.cno = s.cno
)
SELECT r.课程名称, r.学号, r.分数
FROM RankedScores r
WHERE r.排名 <= 3;
22、查询每门课程被选修的学生数
SELECT c.cname AS 课程名, COUNT(s.sno) AS 学生数
FROM course c
LEFT JOIN sc s ON c.cno = s.cno
GROUP BY c.cname;
23、查询出只选修了一门课程的全部学生的学号和姓名
SELECT s.sno AS 学号, s.sname AS 姓名
FROM student s
JOIN (SELECT snoFROM scGROUP BY snoHAVING COUNT(*) = 1
) t ON s.sno = t.sno;
24、查询男生、女生人数
SELECT ssex AS 性别,COUNT(CASE WHEN ssex = '男' THEN 1 END) AS 男生人数,COUNT(CASE WHEN ssex = '女' THEN 1 END) AS 女生人数
FROM student
GROUP BY ssex;
25、查询姓“张”的学生名单
SELECT sname AS 姓名
FROM student
WHERE sname LIKE '张%';
26、查询同名同性学生名单,并统计同名人数
SELECT sname AS 姓名, ssex AS 性别, COUNT(*) AS 人数
FROM student
GROUP BY sname, ssex
HAVING COUNT(*) > 1;
27、1981 年出生的学生名单(注:Student 表中Sage 列的类型是number)
SELECT sname AS 姓名
FROM student
WHERE EXTRACT(YEAR FROM sage) = 1981;
28、查询每门课程的平均成绩,结果按平均成绩升序排列,平均成绩相同时,按课程号降序排列
SELECT cno AS 课程号, AVG(score) AS 平均成绩
FROM sc
GROUP BY cno
ORDER BY AVG(score) ASC, cno DESC;
29、查询平均成绩大于85 的所有学生的学号、姓名和平均成绩
SELECT s.sno AS 学号, s.sname AS 姓名, AVG(sc.score) AS 平均成绩
FROM student s
JOIN sc ON s.sno = sc.sno
GROUP BY s.sno, s.sname
HAVING AVG(sc.score) > 85;
30、查询课程名称为“数据库”,且分数低于60 的学生姓名和分数
SELECT s.sname AS 姓名, sc.score AS 分数
FROM student s
JOIN sc ON s.sno = sc.sno
JOIN course c ON c.cno = sc.cno
WHERE c.cname = '数据库' AND sc.score < 60;
31、查询所有学生的选课情况;
SELECT s.sname AS 学生姓名, c.cname AS 课程名称, t.tname AS 教师姓名, sc.score AS 分数
FROM student s
JOIN sc ON s.sno = sc.sno
JOIN course c ON c.cno = sc.cno
JOIN teacher t ON c.tno = t.tno;
32、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.sname AS 学生姓名, c.cname AS 课程名称, sc.score AS 分数
FROM student s
JOIN sc ON s.sno = sc.sno
JOIN course c ON c.cno = sc.cno
WHERE sc.score >= 70;
33、查询不及格的课程,并按课程号从大到小排列
SELECT c.cno AS 课程号, c.cname AS 课程名
FROM course c
JOIN sc ON c.cno = sc.cno
WHERE sc.score < 60
ORDER BY c.cno DESC;
34、查询课程编号为c001 且课程成绩在80 分以上的学生的学号和姓名;
SELECT s.sno AS 学号, s.sname AS 姓名
FROM student s
JOIN sc ON s.sno = sc.sno
WHERE sc.cno = 'c001' AND sc.score >= 80;
35、求选了课程的学生人数
SELECT COUNT(DISTINCT sno) AS 选课学生人数
FROM sc;
36、查询选修“谌燕”老师所授课程的学生中,成绩最高的学生姓名及其成绩
SELECT s.sname, MAX(sc.score) AS 最高成绩
FROM student s
JOIN sc ON s.sno = sc.sno
JOIN course c ON sc.cno = c.cno
JOIN teacher t ON c.tno = t.tno
WHERE t.tname = '谌燕'
GROUP BY s.sname
ORDER BY 最高成绩 DESC
LIMIT 1;
37、查询各个课程及相应的选修人数
SELECT c.cname AS 课程名, COUNT(sc.sno) AS 选修人数
FROM course c
LEFT JOIN sc ON c.cno = sc.cno
GROUP BY c.cname;
38、查询不同课程成绩相同的学生的学号、课程号、学生成绩
SELECT s1.sno AS 学号, sc1.cno AS 课程号, sc1.score AS 学生成绩
FROM sc sc1, sc sc2, student s1, student s2
WHERE sc1.sno = s1.sno
AND sc2.sno = s2.sno
AND sc1.cno <> sc2.cno
AND sc1.score = sc2.score
AND s1.sno < s2.sno;
39、查询每门功课成绩最好的前两名
SELECT c.cno AS 课程号, c.cname AS 课程名, s.sno AS 学号, s.sname AS 姓名, sc.score AS 分数
FROM course c
INNER JOIN sc ON c.cno = sc.cno
INNER JOIN student s ON sc.sno = s.sno
WHERE (s.sno, sc.score) IN (SELECT sno, MAX(score) FROM sc WHERE cno = c.cno GROUP BY cnoUNIONSELECT sno, MAX(score) FROM sc WHERE cno = c.cno GROUP BY cno)
ORDER BY c.cno, sc.score DESC;
40、统计每门课程的学生选修人数(超过10人的课程才统计)。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 cno AS 课程号, COUNT(sno) AS 选修人数
FROM sc
GROUP BY cno
HAVING COUNT(sno) > 10
ORDER BY COUNT(sno) DESC, cno ASC;
41、检索至少选修两门课程的学生学号
SELECT sno AS 学号
FROM sc
GROUP BY sno
HAVING COUNT(cno) >= 2;
42、查询全部学生都选修的课程的课程号和课程名
SELECT cno AS 课程号, cname AS 课程名
FROM course
WHERE cno NOT IN (SELECT cnoFROM scWHERE sno NOT IN (SELECT snoFROM student)
);
43、查询没学过“谌燕”老师讲授的任一门课程的学生姓名
SELECT sname AS 学生姓名
FROM student
WHERE sno NOT IN (SELECT snoFROM scWHERE cno IN (SELECT cnoFROM courseWHERE tno = (SELECT tnoFROM teacherWHERE tname = '谌燕'))
);
44、查询两门以上不及格课程的同学的学号及其平均成绩
SELECT s.sno AS 学号, AVG(score) AS 平均成绩
FROM student s
JOIN sc ON s.sno = sc.sno
WHERE score < 60
GROUP BY s.sno
HAVING COUNT(*) >= 2;
45、检索“c004”课程分数小于60,按分数降序排列的同学学号
SELECT s.sno AS 学号
FROM student s
JOIN sc ON s.sno = sc.sno
WHERE sc.cno = 'c004' AND sc.score < 60
ORDER BY sc.score DESC;
46、删除“s002”同学的“c001”课程的成绩
DELETE FROM sc
WHERE sno = 's002' AND cno = 'c001';
AIGC ChatGPT 职场案例
AI 绘画 与 短视频制作
PowerBI 商业智能 68集
Mysql 8.0 54集
Oracle 21C 142集
Office 2021实战应用
Python 数据分析实战,
ETL Informatica 数据仓库案例实战 51集
Excel 2021实操 100集,
Excel 2021函数大全 80集
Excel 2021高级图表应用 89集,
Excel 2021大屏可视化制作 56集
Excel 2021实用技巧 300集
PPT 2021 商业汇报实战应用 69集
Tableau 数据分析 80集
FineReport 帆软大屏可视化 50集
送你各类文档模板PPT,表格,大屏可视化 超过5000+模板
以上案例实战获取: https://edu.csdn.net/combo/detail/2552