SQL 經典練習題 + 答案

阿新 • • 發佈：2021-01-15

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, '曾華', '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, '王麗', '女', '1976-01-23', 95033);
INSERT INTO Student (stu_id, stu_name, stu_sex, stu_birthday, stu_class)
VALUES (101, '李軍', '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, '陸君', '男', '1974-06-03', 95031);
 
INSERT INTO Course (cou_id, cou_name, tea_id)
VALUES ('3-105', '計算機導論', 825);
INSERT INTO Course (cou_id, cou_name, tea_id)
VALUES ('3-245', '作業系統', 804);
INSERT INTO Course (cou_id, cou_name, tea_id)
VALUES ('6-166', '資料電路', 856);
INSERT INTO Course (cou_id, cou_name, tea_id)
VALUES ('9-888', '高等數學', 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, '李誠', '男', '1958-12-02', '副教授', '計算機系'); 
INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
VALUES (856, '張旭', '男', '1969-03-12', '講師', '電子工程系');
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', '計算機系');
INSERT INTO Teacher (tea_id, tea_name, tea_sex, tea_birthday, tea_prof, tea_depart)
VALUES (831, '劉冰', '女', '1977-08-14', '助教', '電子工程系');

Student表如下：

Course表：

Score表：

Teacher表：

題目由易到難，題目及答案如下：
 
USE exercise;
 
-- 1、 查詢student表中的所有記錄的stu_name、stu_sex和stu_class列。
SELECT student.stu_name, student.stu_sex, student.stu_class
FROM student;
 
-- 2、 查詢教師所有的單位即不重複的tea_depart列。
SELECT DISTINCT teacher.tea_depart
FROM teacher; 
 
-- 3、 查詢student表的所有記錄。
SELECT * 
FROM student;
 
-- 4、 查詢score表中成績在60到80之間的所有記錄。
SELECT *
FROM score
WHERE sco_degree BETWEEN 60 AND 80;
 
-- 5、 查詢score表中成績為85，86或88的記錄。
-- 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、 查詢student表中“95031”班或性別為“女”的同學記錄。
SELECT * 
FROM student
WHERE stu_class = '95031' 
    OR stu_sex = '女';
 
-- 7、 以stu_class降序查詢student表的所有記錄。
SELECT * FROM student
ORDER BY student.stu_class DESC;
 
-- 8、 以stu_id升序、sco_degree降序查詢score表的所有記錄。
SELECT * 
FROM score
ORDER BY stu_id ASC, sco_degree DESC;
 
-- 9、 查詢“95031”班的學生人數。
SELECT COUNT(*) AS class_95031_num 
FROM student
WHERE stu_class = '95031';
 
-- 10、查詢score表中的最高分的學生學號和課程號。
-- 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、查詢‘3-105’號課程的平均分。
SELECT AVG(sco_degree) AS avg_degree
FROM score
WHERE cou_id = '3-105';
 
-- 12、查詢score表中至少有5名學生選修的並以3開頭的課程的平均分數。
SELECT AVG(sco_degree) AS degree_avg, cou_id
FROM score
WHERE cou_id LIKE '3%'
GROUP BY cou_id
HAVING COUNT(*) >= 5;
 
-- 13、查詢最低分大於70，最高分小於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、查詢所有學生的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、查詢所有學生的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、查詢所有學生的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、查詢“95033”班所選課程的平均分。
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、假設使用如下命令建立了一個grade表, 現查詢所有同學的stu_name、cou_name和gra_rank列。
/*-- 去除註釋進行建立
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、查詢選修“3-105”課程的成績高於“109”號同學成績的所有同學的記錄
-- 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、查詢score中選學一門以上課程的同學中分數為非最高分成績的記錄。
SELECT score.*
FROM score
WHERE score.sco_degree < (SELECT MAX(score.sco_degree) FROM score)
GROUP BY score.stu_id
HAVING COUNT(*) > 1;
 
-- 21、查詢成績高於學號為“109”、課程號為“3-105”的成績的所有記錄。
-- 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、查詢和學號為‘108’的同學同年出生的所有學生的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、查詢“張旭“教師任課的學生成績。   
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 = '張旭';
 
-- 24、查詢選修某課程的同學人數多於5人的教師姓名。
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、查詢95033班和95031班全體學生的記錄。
SELECT *
FROM student 
WHERE stu_class IN ('95031', '95033');
 
-- 26、查詢存在有85分以上成績的課程cou_id。
SELECT score.cou_id
FROM score
GROUP BY score.cou_id
HAVING MAX(sco_degree) > 85;
 
-- 27、查詢出“計算機系“教師所教課程的成績表。
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 = '計算機系';
 
-- 28、查詢“計算機系”與“電子工程系“不同tea_prof的教師的tea_name和tea_prof。
SELECT tea_name, tea_prof
FROM teacher
WHERE tea_depart = '計算機系'
    AND tea_prof NOT IN (SELECT tea_prof 
                         FROM teacher
                         WHERE tea_depart = '電子工程系');
 
-- 29、查詢選修編號為“3-105“課程且成績至少高於選修編號為“3-245”的同學的cou_id、stu_id和sco_degree,並按sco_degree從高到低次序排序。
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、查詢選修編號為“3-105”且成績高於選修編號為“3-245”課程的同學的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、查詢所有教師和同學的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、查詢所有“女”教師和“女”同學的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**、查詢成績比該課程平均成績低的同學的成績表。
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、查詢所有任課教師的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、查詢所有未講課的教師的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、查詢至少有2名男生的班號。
SELECT stu_class
FROM student
WHERE stu_sex = '男'
GROUP BY stu_class
HAVING COUNT(*) >= 2;
 
-- 37、查詢Student表中不姓“王”的同學記錄。
SELECT *
FROM student
WHERE stu_name NOT LIKE '王%';
 
-- 38、查詢Student表中每個學生的姓名和年齡。
SELECT stu_name, YEAR(NOW()) - YEAR(stu_birthday) AS stu_age
FROM student;
 
-- 39、查詢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、以班號和年齡從大到小的順序查詢Student表中的全部記錄。
SELECT student.*, YEAR(NOW()) - YEAR(stu_birthday) AS stu_age
FROM student
ORDER BY stu_class DESC, stu_age DESC;
 
-- 41、查詢“男”教師及其所上的課程。 
SELECT course.*
FROM course INNER JOIN
teacher ON teacher.tea_id = course.tea_id
WHERE teacher.tea_sex = '男';
 
-- 42、查詢最高分同學的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、查詢和“李軍”同性別的所有同學的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 = '李軍');
                    
-- 44、查詢和“李軍”同性別並同班的同學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 = '李軍')
                    AND S1.stu_class = (SELECT S3.stu_class
                    FROM student AS S3
                    WHERE S3.stu_name = '李軍');
                                        
-- 45、查詢所有選修“計算機導論”課程的“男”同學的成績表
SELECT score.*
FROM score, student, course
WHERE score.stu_id = student.stu_id
    AND score.cou_id = course.cou_id
    AND course.cou_name = '計算機導論'
    AND student.stu_sex = '男';