创建student表,SQL代码如下:
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)
);
创建score表,SQL代码如下:
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)
);
向student表插入记录的INSERT语句如下:
INSERT INTO student VALUES( 901,'张老大', '男',1985,'计算机系', '北京市海淀区');
INSERT INTO student VALUES( 902,'张老二', '男',1986,'中文系', '北京市昌平区');
INSERT INTO student VALUES( 903,'张三', '女',1990,'中文系', '湖南省永州市');
INSERT INTO student VALUES( 904,'李四', '男',1990,'英语系', '辽宁省阜新市');
INSERT INTO student VALUES( 905,'王五', '女',1991,'英语系', '福建省厦门市');
INSERT INTO student VALUES( 906,'王六', '男',1988,'计算机系', '湖南省衡阳市');
向score表插入记录的INSERT语句如下:
INSERT INTO score VALUES(NULL,901, '计算机',98);
INSERT INTO score VALUES(NULL,901, '英语', 80);
INSERT INTO score VALUES(NULL,902, '计算机',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, '计算机',70);
INSERT INTO score VALUES(NULL,904, '英语',92);
INSERT INTO score VALUES(NULL,905, '英语',94);
INSERT INTO score VALUES(NULL,906, '计算机',90);
INSERT INTO score VALUES(NULL,906, '英语',85);
mysql> create database db_school;
Query OK, 1 row affected (0.01 sec)
mysql> use db_school;
Database changed
mysql> 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)
-> );
Query OK, 0 rows affected, 1 warning (0.10 sec)
mysql> 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)
-> );
Query OK, 0 rows affected, 3 warnings (2.46 sec)
测试:
mysql> INSERT INTO student VALUES( 901,'张老大', '男',1985,'计算机系', '北京市海淀区');
Query OK, 1 row affected (0.03 sec)
mysql> INSERT INTO student VALUES( 902,'张老二', '男',1986,'中文系', '北京市昌平区');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO student VALUES( 903,'张三', '女',1990,'中文系', '湖南省永州市');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO student VALUES( 904,'李四', '男',1990,'英语系', '辽宁省阜新市');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO student VALUES( 905,'王五', '女',1991,'英语系', '福建省厦门市');
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO student VALUES( 906,'王六', '男',1988,'计算机系', '湖南省衡阳市');
Query OK, 1 row affected (0.00 sec)
测试:
mysql> INSERT INTO score VALUES(NULL,901, '计算机',98);
Query OK, 1 row affected (0.02 sec)
mysql> INSERT INTO score VALUES(NULL,901, '英语', 80);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,902, '计算机',65);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,902, '中文',88);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,903, '中文',95);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,904, '计算机',70);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,904, '英语',92);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,905, '英语',94);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,906, '计算机',90);
Query OK, 1 row affected (0.00 sec)
mysql> INSERT INTO score VALUES(NULL,906, '英语',85);
Query OK, 1 row affected (0.00 sec)
测试:
1.查询student表的所有记录
2.查询student表的第2条到4条记录
3.从student表查询所有学生的学号(id)、姓名(name)和院系(department)的信息
4.从student表中查询计算机系和英语系的学生的信息
5.从student表中查询年龄18~22岁的学生信息
6.从student表中查询每个院系有多少人
7.从score表中查询每个科目的最高分
8.查询李四的考试科目(c_name)和考试成绩(grade)
9.用连接的方式查询所有学生的信息和考试信息
10.计算每个学生的总成绩
11.计算每个考试科目的平均成绩
12.查询计算机成绩低于95的学生信息
13.查询同时参加计算机和英语考试的学生的信息
14.将计算机考试成绩按从高到低进行排序
15.从student表和score表中查询出学生的学号,然后合并查询结果
16.查询姓张或者姓王的同学的姓名、院系和考试科目及成绩
17.查询都是湖南的学生的姓名、年龄、院系和考试科目及成绩