SQL 基础语句练习题(查询)

SQL 基础语句练习题(查询)

查询语句练习题
1.建表
create table student(
id int(10) primary key not null auto_increment,
name varchar(20) not null,
sex varchar(4),
birth year,
department varchar(20) not null,
address varchar(50)
)default charset=utf8;

create table score(
id int(10) primary key not null auto_increment,
stu_id int(10) not null,
c_name varchar(20),
grade int(10)
)default charset=utf8;

2.插入数据
insert into student values(901,‘张老大’,‘男’,1990,‘计算机系’,‘北京市海淀区’);
insert into student (name,sex,birth,department,address) values
(‘张老二’,‘男’,1991,‘中文系’,‘北京市昌平区’),
(‘张三’,‘女’,1995,‘中文系’,‘湖南省永州市’),
(‘李四’,‘男’,1995,‘英语系’,‘辽宁省阜新市’),
(‘王五’,‘女’,1996,‘英语系’,‘福建省厦门市’),
(‘王六’,‘男’,1993,‘计算机系’,‘湖南省衡阳市’);

insert into score values(NULL,901,‘计算机’,98);
insert into score (stu_id,c_name,grade) values
(901,‘英语’,80),
(902,‘计算机’,65),
(902,‘中文’,88),
(903,‘中文’,95),
(904,‘计算机’,70),
(904,‘英语’,92),
(905,‘英语’,94),
(906,‘计算机’,90),
(906,‘英语’,85);

3.查询student表的所有记录
select * from student;

4.查询student表的第2条到第4条记录
select * from student limit 1,3;

5.从student表查询所有学生的学号、姓名和院系信息
select id,name,department from student;

6.从student表中查询计算机系和英语系的学生的信息
select *
from student
where department in (‘计算机系’,‘英语系’);

7.从student表中查询年龄18~22岁的学生信息
select *
from student
where 2018-birth between 18 and 22;

8.从student表中查询每个院系有多少人
select department,count(department)
from student
group by department;

9.从score表中查询每个科目的最高分
select c_name,max(grade)
from score
group by c_name;

10.查询李四的考试科目和考试成绩
select c_name,grade
from score
where stu_id in (select id from student where name=‘李四’);

11.用连接的方式查询所有学生的信息和考试信息
select a.*,b.c_name,b.grade
from student a,score b
where a.id=b.stu_id
order by a.id;

12.计算每个学生的总成绩
select stu_id,count(c_name),sum(grade)
from score
group by stu_id;

13.计算每个考试科目的平均成绩
select c_name,avg(grade)
from score
group by c_name;

14.查询计算机成绩低于95的学生信息
select *
from student
where id in (select stu_id from score where c_name=‘计算机’ and grade<95);

15.查询同时参加计算机和英语考试的学生的信息
select *
from student
where id in (select a.stu_id from score a,score b where a.stu_id=b.stu_id and a.c_name=‘计算机’ and b.c_name=‘英语’);

16.将计算机考试成绩按从高到低排序
select stu_id,grade
from score
where c_name=‘计算机’
order by grade desc;

17.从student表和score表中查询出学生的学号，然后合并查询结果
select id from student
union
select stu_id from score;

18.查询姓张或者姓王的同学的姓名、院系和考试科目及成绩
select a.name,a.department,b.c_name,b.grade
from student a,score b
where a.id=b.stu_id and a.name regexp ‘¹’;
题意 张、王必须为姓，即以其中之一开头

19.查询都是湖南的学生的姓名、年龄、院系和考试科目及成绩
select a.name,2018-a.birth as age,a.department,b.c_name,b.grade

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1. 张王 ↩︎