day06 作业--技能题1

1.创建test数据库

 create database test character set utf8;

2.在test数据库中创建student表,(id设置为主键自增长)

create table student(
id int primary key auto_increment,
name varchar(20),
score int,
address varchar(50),
useremail varchar(20)
)

desc student;

 3.向student表中添加记录

insert into student value(1,'张三',98,'北京','[email protected]'),(2,'李四',88,'上海','[email protected]'),(3,'王五',78,'广州','[email protected]'),(4,'赵六',68,'深圳','[email protected]'),(5,'孙七',58,'杭州','[email protected]'),(6,'小红',48,'北京','[email protected]'),(7,'小黑',99,'上海','[email protected]'),(8,'小绿',100,'杭州','[email protected]'),(9,'小粉',60,'杭州','[email protected]'),(10,'小紫',70,'黑龙江','[email protected]')

4. 使用sql语句查询出表中的所有内容

SELECT * from student;

5. 使用sql语句查询出表中所有score>70的同学的id,name,score

select id,name,score from student where score>70;

6.更改name字段的数据类型为varchar(50)

alter table student MODIFY COLUMN name varchar(50);
desc student;

7.向表中添加一个字段，字段名称为“pingjia”,字段类型为varchar(20)

alter table student add pingjia varchar(20);
desc student;

8.更改姓名是张三的同学的分数为88

update student set score=88 where name='张三';
select * from student;

 

9.如果80分为及格线，查询出所有及格的同学的详细信息

select * from student where score >=80;

 

10.使用关键字in,查询id值是1或5或7的同学的基本信息

select * from student where id in(1,5,7);

  

11.查询id值在5至8的所有同学的基本信息

select * from student where id between 5 and 8;

12.查询姓名是小红并且分数大于60的同学的基本信息

select * from student where name='小红' and score>60;

13.查询姓名是小红或者分数大于90的同学的基本信息

select * from student where name='小红' or score>90;