SQL 经典练习题 + 答案

深藏阁楼爱情的钟 2022-05-24 20:07 329阅读 0赞

### **【写在前面】** ###

最近学了 sql，然后找了些 sql 查询的习题来做一下，感觉得到了一些提高，

所以将题目+答案分享一下，我使用的是 MySQL Workbench 6.3 CE，基本没有问题。

创建模式，表：

CREATE SCHEMA exercise;
    
    USE exercise;
    
    CREATE TABLE Student
    (
    	stu_id 			VARCHAR(3) NOT NULL, 
    	stu_name 		VARCHAR(4) NOT NULL,
    	stu_sex 		VARCHAR(2) NOT NULL, 
            stu_birthday            DATETIME NOT NULL,
    	stu_class 		VARCHAR(5)
    );
    
    CREATE TABLE Course
    (
    	cou_id 		VARCHAR(5) NOT NULL, 
    	cou_name 	VARCHAR(10) NOT NULL, 
    	tea_id 		VARCHAR(10) NOT NULL
    );
    
    CREATE TABLE Score 
    (
    	stu_id 		VARCHAR(3) NOT NULL, 
    	cou_id 		VARCHAR(5) NOT NULL, 
    	sco_degree 	NUMERIC(10, 1) NOT NULL
    );
    
    CREATE TABLE Teacher
    (
        tea_id          VARCHAR(3) NOT NULL,
        tea_name        VARCHAR(4) NOT NULL,
        tea_sex         VARCHAR(2) NOT NULL,
        tea_birthday    DATETIME NOT NULL,
        tea_prof        VARCHAR(6), 
        tea_depart      VARCHAR(10) NOT NULL
    );
    
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (108, '曾华', '男', '1977-09-01', 95033);
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (105, '匡明', '男', '1975-10-02', 95031);
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (107, '王丽', '女', '1976-01-23', 95033);
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (101, '李军', '男', '1976-02-20', 95033);
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (109, '王芳', '女', '1975-02-10', 95031);
    INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
    VALUES (103, '陆君', '男', '1974-06-03', 95031);
    
    INSERT INTO Course (cou_id, cou_name, tea_id)
    VALUES ('3-105', '计算机导论', 825);
    INSERT INTO Course (cou_id, cou_name, tea_id)
    VALUES ('3-245', '操作系统', 804);
    INSERT INTO Course (cou_id, cou_name, tea_id)
    VALUES ('6-166', '数据电路', 856);
    INSERT INTO Course (cou_id, cou_name, tea_id)
    VALUES ('9-888', '高等数学', 100);
    
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (103, '3-245', 86); 
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (105, '3-245', 75);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (109, '3-245', 68);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (103, '3-105', 92);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (105, '3-105', 88);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (109, '3-105', 76);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (101, '3-105', 64);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (107, '3-105', 91);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (108, '3-105', 78);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (101, '6-166', 85);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (107, '6-166', 79);
    INSERT INTO Score (stu_id, cou_id, sco_degree)
    VALUES (108, '6-166', 81);
    
    INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
    VALUES (804, '李诚', '男', '1958-12-02', '副教授', '计算机系'); 
    INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
    VALUES (856, '张旭', '男', '1969-03-12', '讲师', '电子工程系');
    INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
    VALUES (825, '王萍', '女', '1972-05-05', '助教', '计算机系');
    INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
    VALUES (831, '刘冰', '女', '1977-08-14', '助教', '电子工程系');

Student表如下：

![20180516191554446][]

Course表：

![20180516191535540][]

Score表：

![20180516191518344][]

Teacher表：

![20180516191455986][]

题目由易到难，题目及答案如下：
    
    USE exercise;
    
    -- 1、 查询student表中的所有记录的stu_name、stu_sex和stu_class列。
    SELECT student.stu_name, student.stu_sex, student.stu_class
    FROM student;
    
    -- 2、 查询教师所有的单位即不重复的tea_depart列。
    SELECT DISTINCT teacher.tea_depart
    FROM teacher; 
    
    -- 3、 查询student表的所有记录。
    SELECT * 
    FROM student;
    
    -- 4、 查询score表中成绩在60到80之间的所有记录。
    SELECT *
    FROM score
    WHERE sco_degree BETWEEN 60 AND 80;
     
    -- 5、 查询score表中成绩为85，86或88的记录。
    -- 解法1
    SELECT *
    FROM score
    WHERE sco_degree IN (85, 86, 88);
    -- 解法2
    SELECT *
    FROM score
    WHERE sco_degree = 85 OR sco_degree = 86 OR sco_degree = 88;
    
    -- 6、 查询student表中“95031”班或性别为“女”的同学记录。
    SELECT * 
    FROM student
    WHERE stu_class = '95031' 
        OR stu_sex = '女';
    
    -- 7、 以stu_class降序查询student表的所有记录。
    SELECT * FROM student
    ORDER BY student.stu_class DESC;
    
    -- 8、 以stu_id升序、sco_degree降序查询score表的所有记录。
    SELECT * 
    FROM score
    ORDER BY stu_id ASC, sco_degree DESC;
    
    -- 9、 查询“95031”班的学生人数。
    SELECT COUNT(*) AS class_95031_num 
    FROM student
    WHERE stu_class = '95031';
    
    -- 10、查询score表中的最高分的学生学号和课程号。
    -- 解法1
    SELECT stu_id, cou_id
    FROM score
    WHERE sco_degree = (SELECT MAX(sco_degree)
                        FROM score);
    -- 解法2
    SELECT stu_id, cou_id
    FROM score
    ORDER BY sco_degree DESC LIMIT 1;
    						
    -- 11、查询‘3-105’号课程的平均分。
    SELECT AVG(sco_degree) AS avg_degree
    FROM score
    WHERE cou_id = '3-105';
    
    -- 12、查询score表中至少有5名学生选修的并以3开头的课程的平均分数。
    SELECT AVG(sco_degree) AS degree_avg, cou_id
    FROM score
    WHERE cou_id LIKE '3%'
    GROUP BY cou_id
    HAVING COUNT(*) >= 5;
    
    -- 13、查询最低分大于70，最高分小于90的stu_id列。
    SELECT stu_id -- 或者 SELECT DISTINCT stu_id
    FROM score
    GROUP BY stu_id
    HAVING MIN(sco_degree) > 70 
        AND MAX(sco_degree) < 90;
        
    -- 14、查询所有学生的stu_name、cou_id和sco_egree列。
    SELECT student.stu_name, score.cou_id, score.sco_degree
    FROM student INNER JOIN 
    score ON student.stu_id = score.stu_id;
    
    -- 15、查询所有学生的stu_id、cou_name和sco_degree列。
    SELECT score.stu_id, course.cou_name, score.sco_degree
    FROM score INNER JOIN 
    course ON score.cou_id = course.cou_id;
    
    -- 16、查询所有学生的stu_name、cou_name和sco_degree列。
    SELECT student.stu_name, course.cou_name, score.sco_degree
    FROM student, course, score
    WHERE student.stu_id = score.stu_id 
        AND course.cou_id = score.cou_id; 
    
    -- 17、查询“95033”班所选课程的平均分。
    SELECT student.stu_class, AVG(score.sco_degree) AS degree_avg
    FROM student INNER JOIN 
    score ON student.stu_id = score.stu_id
    WHERE student.stu_class = '95031';
    
    -- 18、假设使用如下命令建立了一个grade表, 现查询所有同学的stu_name、cou_name和gra_rank列。
    /*-- 去除注释进行创建
    CREATE TABLE grade
    (
    	gra_low   NUMERIC(3, 0),
    	gra_upp   NUMERIC(3),
    	gra_rank  CHAR(1)
     );
     
    INSERT INTO grade VALUES(90, 100, 'A');
    INSERT INTO grade VALUES(80, 89, 'B');
    INSERT INTO grade VALUES(70, 79, 'C');
    INSERT INTO grade VALUES(60, 69, 'D');
    INSERT INTO grade VALUES(0, 59, 'E');
    
    COMMIT;
    */
    SELECT student.stu_name, course.cou_name, grade.gra_rank
    FROM score, student, course, grade
    WHERE student.stu_id = score.stu_id
        AND score.cou_id = course.cou_id
        AND (score.sco_degree BETWEEN grade.gra_low AND grade.gra_upp);
       
    -- 19、查询选修“3-105”课程的成绩高于“109”号同学成绩的所有同学的记录
    -- 解法1
    SELECT *
    FROM score
    WHERE score.cou_id = '3-105'
    	AND score.sco_degree > (SELECT sco_degree
    				FROM score
    				WHERE score.cou_id = '3-105' AND score.stu_id = '109');
    -- 解法2
    SELECT s1.*
    FROM score AS s1 INNER JOIN 
    score AS s2 ON s1.cou_id = s2.cou_id
    WHERE s1.cou_id = '3-105'
    	AND s1.sco_degree > s2.sco_degree
    	AND s2.cou_id = '3-105' AND s2.stu_id = '109';
    
    -- 20、查询score中选学一门以上课程的同学中分数为非最高分成绩的记录。
    SELECT score.*
    FROM score
    WHERE score.sco_degree < (SELECT MAX(score.sco_degree) FROM score)
    GROUP BY score.stu_id
    HAVING COUNT(*) > 1;
    
    -- 21、查询成绩高于学号为“109”、课程号为“3-105”的成绩的所有记录。
    -- 解法1
    SELECT s1.*
    FROM score AS s1 INNER JOIN 
    score AS s2 ON s1.cou_id = s2.cou_id
    WHERE s1.cou_id = '3-105'
        AND s1.sco_degree > s2.sco_degree
        AND s2.cou_id = '3-105' AND s2.stu_id = '109';
    -- 解法2
    SELECT *
    FROM score
    WHERE score.sco_degree > (SELECT score.sco_degree
                              FROM score
                              WHERE score.stu_id = '109' AND score.cou_id = '3-105');
    
    -- 22、查询和学号为‘108’的同学同年出生的所有学生的stu_id、stu_name和stu_birthday列。
    -- 解法1
    SELECT s1.stu_id, s1.stu_name, s1.stu_birthday
    FROM student AS s1 INNER JOIN 
    student AS s2 ON s1.stu_id = s2.stu_id
    WHERE YEAR(s1.stu_birthday) = YEAR(s2.stu_birthday) AND s2.stu_id = '108';
    
    -- 解法2
    SELECT student.stu_id, student.stu_name, student.stu_birthday
    FROM student
    WHERE YEAR(student.stu_birthday) = (SELECT YEAR(student.stu_birthday)
                                        FROM student
                                        WHERE student.stu_id = '108');
    							
    -- 23、查询“张旭“教师任课的学生成绩。   
    SELECT score.sco_degree, score.stu_id
    FROM score, course, teacher
    WHERE score.cou_id = course.cou_id 
        AND course.tea_id = teacher.tea_id
        AND teacher.tea_name = '张旭';
    
    -- 24、查询选修某课程的同学人数多于5人的教师姓名。
    SELECT teacher.tea_name
    FROM teacher, course, score
    WHERE teacher.tea_id = course.tea_id
    	AND course.cou_id = score.cou_id
    GROUP BY teacher.tea_name
    HAVING COUNT(*) > 5;
    
    -- 25、查询95033班和95031班全体学生的记录。
    SELECT *
    FROM student 
    WHERE stu_class IN ('95031', '95033');
    
    -- 26、查询存在有85分以上成绩的课程cou_id。
    SELECT score.cou_id
    FROM score
    GROUP BY score.cou_id
    HAVING MAX(sco_degree) > 85;
    
    -- 27、查询出“计算机系“教师所教课程的成绩表。
    SELECT student.stu_name, score.sco_degree, course.cou_name, teacher.tea_name
    FROM score, teacher, course, student
    WHERE student.stu_id = score.stu_id
        AND score.cou_id = course.cou_id
        AND course.tea_id = teacher.tea_id
        AND teacher.tea_depart = '计算机系';
    
    -- 28、查询“计算机系”与“电子工程系“不同tea_prof的教师的tea_name和tea_prof。
    SELECT tea_name, tea_prof
    FROM teacher
    WHERE tea_depart = '计算机系'
        AND tea_prof NOT IN (SELECT tea_prof 
                             FROM teacher
                             WHERE tea_depart = '电子工程系');
    
    -- 29、查询选修编号为“3-105“课程且成绩至少高于选修编号为“3-245”的同学的cou_id、stu_id和sco_degree,并按sco_degree从高到低次序排序。
    SELECT score.cou_id, score.stu_id, score.sco_degree
    FROM score
    WHERE cou_id = '3-105'
        AND sco_degree > ANY(SELECT sco_degree
                             FROM score
                             WHERE cou_id = '3-245')
                             ORDER BY score.sco_degree DESC;
    
    -- 30、查询选修编号为“3-105”且成绩高于选修编号为“3-245”课程的同学的cou_id、stu_id和sco_degree。
    SELECT cou_id, stu_id, sco_degree
    FROM score
    WHERE cou_id = '3-105'
        AND sco_degree > ALL(SELECT sco_degree
                             FROM score
                             WHERE cou_id = '3-245')
                             ORDER BY sco_degree DESC;
                             
    -- 31、查询所有教师和同学的name、sex和birthday。
    SELECT tea_name AS name, tea_sex AS sex,  tea_birthday AS birthday
    FROM teacher
    UNION 
    SELECT stu_name, stu_sex, stu_birthday
    FROM student;
    
    -- 32、查询所有“女”教师和“女”同学的name、sex和birthday。
    SELECT tea_name AS name, tea_sex AS sex,  tea_birthday AS birthday
    FROM teacher
    WHERE tea_sex = '女'
    UNION 
    SELECT stu_name, stu_sex, stu_birthday
    FROM student
    WHERE stu_sex = '女';
    
    -- 33**、查询成绩比该课程平均成绩低的同学的成绩表。
    SELECT cou_id, sco_degree, stu_id
    FROM score AS A
    WHERE sco_degree < (SELECT AVG(sco_degree)
                        FROM score AS B
                        WHERE A.cou_id = B.cou_id);
    
    -- 34、查询所有任课教师的tea_name和tea_depart。
    SELECT tea_name, tea_depart
    FROM teacher AS T
    WHERE T.tea_id IN (SELECT C.tea_id
                       FROM course AS C);
    
    -- 35、查询所有未讲课的教师的tea_name和tad_depart。
    SELECT tea_name, tea_depart
    FROM teacher AS T
    WHERE T.tea_id NOT IN (SELECT C.tea_id
                           FROM course AS C);
                            
    -- 36、查询至少有2名男生的班号。
    SELECT stu_class
    FROM student
    WHERE stu_sex = '男'
    GROUP BY stu_class
    HAVING COUNT(*) >= 2;
    
    -- 37、查询Student表中不姓“王”的同学记录。
    SELECT *
    FROM student
    WHERE stu_name NOT LIKE '王%';
    
    -- 38、查询Student表中每个学生的姓名和年龄。
    SELECT stu_name, YEAR(NOW()) - YEAR(stu_birthday) AS stu_age
    FROM student;
    
    -- 39、查询Student表中最大和最小的stu_birthday日期值
    SELECT MAX(stu_birthday) AS max_birthday, MIN(stu_birthday) AS min_birthday
    FROM student;
    
    -- 40、以班号和年龄从大到小的顺序查询Student表中的全部记录。
    SELECT student.*, YEAR(NOW()) - YEAR(stu_birthday) AS stu_age
    FROM student
    ORDER BY stu_class DESC, stu_age DESC;
    
    -- 41、查询“男”教师及其所上的课程。 
    SELECT course.*
    FROM course INNER JOIN
    teacher ON teacher.tea_id = course.tea_id
    WHERE teacher.tea_sex = '男';
    
    -- 42、查询最高分同学的stu_id、cou_id和sco_degree列。
    SELECT S1.*
    FROM score AS S1
    WHERE S1.sco_degree = (SELECT MAX(S2.sco_degree)
    		       FROM score AS S2);
                           
    -- 43、查询和“李军”同性别的所有同学的stu_name.
    SELECT S1.stu_name
    FROM student AS S1
    WHERE S1.stu_sex = (SELECT S2.stu_sex
                        FROM student AS S2
                        WHERE s2.stu_name = '李军');
                        
    -- 44、查询和“李军”同性别并同班的同学stu_name.
    SELECT S1.stu_name
    FROM student AS S1
    WHERE S1.stu_sex = (SELECT S2.stu_sex
                        FROM student AS S2
                        WHERE s2.stu_name = '李军')
                        AND S1.stu_class = (SELECT S3.stu_class
    					FROM student AS S3
    					WHERE S3.stu_name = '李军');
                                            
    -- 45、查询所有选修“计算机导论”课程的“男”同学的成绩表
    SELECT score.*
    FROM score, student, course
    WHERE score.stu_id = student.stu_id
        AND score.cou_id = course.cou_id
        AND course.cou_name = '计算机导论'
        AND student.stu_sex = '男';

另外，推荐SQL入门书籍：SQL必知必会。

[20180516191554446]: /images/20220525/af679477fcc2416b9838f9b3c1e8cc58.png
[20180516191535540]: /images/20220525/80564494a7b542299fef30dc505f984a.png
[20180516191518344]: /images/20220525/3c6a6ff5918c4bbcac0d8a58351f0be9.png
[20180516191455986]: /images/20220525/3cc9308852c24e8b9be094159d8ec8a9.png