【MySQL】經典資料庫SQL語句編寫練習題——SQL語句掃盲
【MySQL】資料庫原理複習——SQL語言
對基本的SQL語句編寫的練習題,其中的題目的答案可能會有多種書寫方式。
1、題目1
1.1 關係模式
學生student:SNO:學號,SNAME:姓名,AGE:年齡 SEX:性別
SNO |
SNAME |
AGE |
SEX |
1 |
23 |
男 |
|
2 |
22 |
女 |
|
5 |
22 |
男 |
課程course:CNO:課程程式碼,CNAME:課程名稱,TEACHER:教師
CNO |
CNAME |
TEACHER |
K1 |
C語言 |
|
K5 |
資料庫原理 |
程軍 |
K8 |
編譯原理 |
程軍 |
學生成績SC:SNO:學號,CNO:課程程式碼,SCORE:成績
SNO |
CNO |
SCORE |
1 |
K1 |
83 |
2 |
K1 |
85 |
5 |
K1 |
92 |
2 |
K5 |
90 |
5 |
K5 |
84 |
5 |
K8 |
80 |
1.2 要求一
用SQL語言完成表的建立以及資料的插入:
use test; create table if not exists student ( SNO varchar(20) primary key, SNAME varchar(20) character set gbk, AGE int, SEX char(2) character set gbk CHECK(SEX IN('男','女')) ); insert into student values('1','李強',23,'男'); insert into student values('2','劉麗',22,'女'); insert into student values('5','張友',22,'男'); create table if not exists course ( CNO varchar(20) primary key, CNAME varchar(20) character set gbk, TEACHER varchar(20) character set gbk ); insert into course values('K1','C語言','王華'); insert into course values('K5','資料庫原理','程軍'); insert into course values('K8','編譯原理','程軍'); create table if not exists sc ( SNO varchar(20) NOT NULL, CNO varchar(20) NOT NULL, SCORE int NOT NULL, primary key (SNO,CNO), foreign key (SNO) references student(SNO), foreign key (CNO) references course(CNO) ); insert into sc values('1','K1',83); insert into sc values('2','K1',85); insert into sc values('5','K1',92); insert into sc values('2','K5',90); insert into sc values('5','K5',84); insert into sc values('5','K8',80);
1.3 要求二
用SQL語言完成如下要求:
(1) 檢索至少選修"程軍"老師所授全部課程的學生姓名(SNAME);
本題的另外一種說法就是,檢索選修了“程軍”老師所授全部課程的學生姓名
select sname from student where not exists ( select * from course where teacher='程軍' and not exists ( select * from sc where sc.sno=student.sno and sc.cno=course.cno ) );
這裡的檢索結果是:
+-------+
| sname |
+-------+
| 張友 |
+-------+
1 row in set (0.00 sec)
(2) 檢索"李強"同學不學課程的課程號(CNO);
select course.cno from course
where course.cno not in
(
select sc.cno from sc,student
where student.sname='李強' and student.sno=sc.sno
);
+-----+
| cno |
+-----+
| K5 |
| K8 |
+-----+
2 rows in set (0.22 sec)
(3) 檢索選修不少於3門課程的學生學號(SNO);
SELECT sc.sno
FROM sc
GROUP BY sc.sno HAVING count(*)>=3
;
+-----+
| sno |
+-----+
| 5 |
+-----+
1 row in set (0.09 sec)
(4) 檢索選修全部課程的學生姓名(SNAME)。
SELECT sname FROM student
WHERE NOT EXISTS
(
SELECT * FROM course
WHERE NOT EXISTS
(
SELECT * FROM sc
WHERE course.cno=sc.cno and student.sno=sc.sno
)
);
+-------+
| sname |
+-------+
| 張友 |
+-------+
1 row in set (0.02 sec)
(5) 檢索不學"C語言"的學生資訊
SELECT * FROM student
WHERE sno not in
(
SELECT sc.sno FROM sc,course
WHERE course.cno=sc.cno
);
1.4 要求三
請用SQL語言完成如下查詢:
(1)查詢“程軍”老師所教授的所有課程;
SELECT * FROM course
WHERE teacher='程軍';
(2)查詢“李強”同學所有課程的成績;
SELECT score FROM student,sc
WHERE student.sname='李強' AND student.sno=sc.sno
(3)查詢課程名為“C語言”的平均成績;
SELECT AVG(score) FROM sc,course
WHERE course.cname='C語言' AND course.cno=sc.cno
(4)查詢選修了所有課程的同學資訊。
SELECT * FROM student
WHERE NOT EXISTS
(
SELECT * FROM course
WHERE NOT EXISTS
(
SELECT * FROM sc
WHERE course.cno=sc.cno AND student.sno=sc.sno
)
);
1.5 要求四
(1)檢索王老師所授課程的課程號和課程名。
SELECT cno,cname FROM course WHERE teacher LIKE '王%';
(2)檢索年齡大於23歲的男學生的學號和姓名。
SELECT sno,sname FROM student
WHERE age>23;
(3)檢索至少選修王老師所授課程中一門課程的女學生姓名。
SELECT sname FROM student
WHERE sex='女' AND sno IN
(
SELECT distinct sno FROM sc,course
WHERE teacher LIKE '王%' AND sc.cno=course.cno
);
(4)檢索李同學不學的課程的課程號。
SELECT course.cno FROM course
WHERE course.cno NOT IN
(
SELECT sc.cno FROM sc,student
WHERE student.sname LIKE '李%' AND sc.sno=student.sno
);
(5)檢索至少選修兩門課程的學生學號。
SELECT sno FROM sc
GROUP BY sno HAVING (count(*)>=2);
(6)檢索全部學生都選修的課程的課程號與課程名。
SELECT course.cno,course.cname FROM course
WHERE course.cno IN
(
SELECT cno FROM sc
GROUP BY cno HAVing count(*)=(SELECT count(*) FROM student)
);
(7)檢索選修課程包含王老師所授課的學生學號。SELECT DISTINCT sno FROM sc
WHERE cno IN
(
SELECT cno FROM course
WHERE teacher LIKE '王%'
);
(8)統計有學生選修的課程門數。
SELECT count(*) NumberOfCourse
FROM
(
SELECT DISTINCT cno FROM sc
GROUP BY cno
) AS testTab;
(9)求選修K1課程的學生的平均年齡。SELECT AVG(age) AverageOfAge
FROM student
WHERE sno IN
(
SELECT sno FROM sc
WHERE cno='K1'
);
(10)求王老師所授課程的每門課程的學生平均成績。SELECT sc.cno,AVG(sc.score)
FROM sc
WHERE sc.cno IN
(
SELECT course.cno FROM course
WHERE course.teacher LIKE '王%'
)
GROUP BY sc.cno
(11)統計每門課程的學生選修人數(超過2人的課程才統計)。要求輸出課程號和選修人數,查詢結果按人數降序排列,若人數相同,按課程號升序排列。
SELECT cno,Num
FROM
(
SELECT cno,count(*) as Num
FROM sc
GROUP BY cno HAVING (count(*) >= 2)
) tb_temp
ORDER BY Num DESC,cno ASC
;
(12)檢索學號比李同學大,而年齡比他小的學生姓名。
SELECT stu1.sname
FROM student stu1,
(
SELECT max(sno) snoLi,min(age) ageLi FROM student
WHERE sname LIKE '李%'
) AS stuLi
WHERE (stu1.age < stuLi.ageLi) AND (stu1.sno>stuLi.snoLi)
;
(13)檢索姓名以李打頭的所有學生的姓名和年齡。
SELECT sname,age FROM student
WHERE sname LIKE '李%'
;
(14)在SC中檢索成績為空值的學生學號和課程號。
SELECT sno,cno FROM sc
WHERE score IS NULL;
(15)求年齡大於女同學平均年齡的男學生姓名和年齡。
SELECT sname,age FROM student
WHERE
sex='男' AND age > (
SELECT AVG(age)
FROM student
WHERE sex='女'
)
;
(16)求年齡大於所有女同學年齡的男學生姓名和年齡。SELECT sname,age
FROM student
WHERE sex='男' AND age > (
SELECT max(age)
FROM student
WHERE sex='女'
)
;