1.創(chuàng)建student和score表

CREATE  TABLE  student (
id  INT(10)  NOT NULL  UNIQUE  PRIMARY KEY  ,
name  VARCHAR(20)  NOT NULL ,
sex  VARCHAR(4)  ,
birth  YEAR,
department  VARCHAR(20) ,
address  VARCHAR(50) 
);

創(chuàng)建score表。SQL代碼如下：
CREATE TABLE score (
id INT(10) NOT NULL UNIQUE PRIMARY KEY AUTO_INCREMENT ,
stu_id INT(10) NOT NULL ,
c_name VARCHAR(20) ,
grade INT(10)
);

2.為student表和score表增加記錄
向student表插入記錄的INSERT語(yǔ)句如下：
INSERT INTO student VALUES( 901,'張老大', '男',1985,'計(jì)算機(jī)系', '北京市海淀區(qū)');
INSERT INTO student VALUES( 902,'張老二', '男',1986,'中文系', '北京市昌平區(qū)');
INSERT INTO student VALUES( 903,'張三', '女',1990,'中文系', '湖南省永州市');
INSERT INTO student VALUES( 904,'李四', '男',1990,'英語(yǔ)系', '遼寧省阜新市');
INSERT INTO student VALUES( 905,'王五', '女',1991,'英語(yǔ)系', '福建省廈門(mén)市');
INSERT INTO student VALUES( 906,'王六', '男',1988,'計(jì)算機(jī)系', '湖南省衡陽(yáng)市');

向score表插入記錄的INSERT語(yǔ)句如下：
INSERT INTO score VALUES(NULL,901, '計(jì)算機(jī)',98);
INSERT INTO score VALUES(NULL,901, '英語(yǔ)', 80);
INSERT INTO score VALUES(NULL,902, '計(jì)算機(jī)',65);
INSERT INTO score VALUES(NULL,902, '中文',88);
INSERT INTO score VALUES(NULL,903, '中文',95);
INSERT INTO score VALUES(NULL,904, '計(jì)算機(jī)',70);
INSERT INTO score VALUES(NULL,904, '英語(yǔ)',92);
INSERT INTO score VALUES(NULL,905, '英語(yǔ)',94);
INSERT INTO score VALUES(NULL,906, '計(jì)算機(jī)',90);
INSERT INTO score VALUES(NULL,906, '英語(yǔ)',85);

3.查詢student表的所有記錄
mysql> SELECT * FROM student;

4.查詢student表的第2條到4條記錄
mysql> SELECT * FROM student LIMIT 1,3;

5.從student表查詢所有學(xué)生的學(xué)號(hào)（id）、姓名（name）和院系（department）的信息
mysql> SELECT id,name,department FROM student;

6.從student表中查詢計(jì)算機(jī)系和英語(yǔ)系的學(xué)生的信息
mysql> SELECT * FROM student WHERE department IN ('計(jì)算機(jī)系','英語(yǔ)系');

7.從student表中查詢年齡18~22歲的學(xué)生信息
mysql> SELECT id,name,sex,2013-birth AS age,department,address
-> FROM student
-> WHERE 2013-birth BETWEEN 18 AND 22;

mysql> SELECT id,name,sex,2013-birth AS age,department,address
-> FROM student
-> WHERE 2013-birth>=18 AND 2013-birth<=22;

8.從student表中查詢每個(gè)院系有多少人
mysql> SELECT department, COUNT(id) FROM student GROUP BY department;

9.從score表中查詢每個(gè)科目的最高分
mysql> SELECT c_name,MAX(grade) FROM score GROUP BY c_name;

10.查詢李四的考試科目（c_name）和考試成績(jī)（grade）
mysql> SELECT c_name, grade
-> FROM score WHERE stu_id=
-> (SELECT id FROM student
-> WHERE name= '李四' );

11.用連接的方式查詢所有學(xué)生的信息和考試信息
mysql> SELECT student.id,name,sex,birth,department,address,c_name,grade
-> FROM student,score
-> WHERE student.id=score.stu_id;

12.計(jì)算每個(gè)學(xué)生的總成績(jī)
mysql> SELECT student.id,name,SUM(grade) FROM student,score
-> WHERE student.id=score.stu_id
-> GROUP BY id;

13.計(jì)算每個(gè)考試科目的平均成績(jī)
mysql> SELECT c_name,AVG(grade) FROM score GROUP BY c_name;

14.查詢計(jì)算機(jī)成績(jī)低于95的學(xué)生信息
mysql> SELECT * FROM student
-> WHERE id IN
-> (SELECT stu_id FROM score
-> WHERE c_name="計(jì)算機(jī)" and grade<95);

15.查詢同時(shí)參加計(jì)算機(jī)和英語(yǔ)考試的學(xué)生的信息
mysql> SELECT * FROM student
-> WHERE id =ANY
-> ( SELECT stu_id FROM score
-> WHERE stu_id IN (
-> SELECT stu_id FROM
-> score WHERE c_name= '計(jì)算機(jī)')
-> AND c_name= '英語(yǔ)' );

mysql> SELECT a.* FROM student a ,score b ,score c
-> WHERE a.id=b.stu_id
-> AND b.c_name='計(jì)算機(jī)'
-> AND a.id=c.stu_id
-> AND c.c_name='英語(yǔ)';

16.將計(jì)算機(jī)考試成績(jī)按從高到低進(jìn)行排序
mysql> SELECT stu_id, grade
-> FROM score WHERE c_name= '計(jì)算機(jī)'
-> ORDER BY grade DESC;

17.從student表和score表中查詢出學(xué)生的學(xué)號(hào)，然后合并查詢結(jié)果
mysql> SELECT id FROM student
-> UNION
-> SELECT stu_id FROM score;

18.查詢姓張或者姓王的同學(xué)的姓名、院系和考試科目及成績(jī)
mysql> SELECT student.id, name,sex,birth,department, address, c_name,grade
-> FROM student, score
-> WHERE
-> (name LIKE '張%' OR name LIKE '王%')
-> AND
-> student.id=score.stu_id ;

19.查詢都是湖南的學(xué)生的姓名、年齡、院系和考試科目及成績(jī)
mysql> SELECT student.id, name,sex,birth,department, address, c_name,grade
-> FROM student, score
-> WHERE address LIKE '湖南%' AND
-> student.id=score.stu_id;