编辑代码

show DATABASES;
CREATE DATABASE test; 
show DATABASES;
use test;
CREATE TABLE student(
   XMH int not null,
   zhigonghao int,
   GZL varchar(30),
    primary key(XMH,zhigonghao)
);
INSERT INTO student VALUES(1,1,'五天');
INSERT INTO student VALUES(2,12,'五天');
INSERT INTO student VALUES(3,123,'六天');
delete from student where XMH=3;

update student set zhigonghao=13 where XMH=2;
insert into student(XMH,zhigonghao,GZL)
values(4,1234,'六天');
SELECT   *  FROM  student;

alter table  student add  zhuchezhibeng varchar(30);
desc student;

alter table student MODIFY GZL varchar(40);
desc student;

alter table student CHANGE GZL gongzhuoliang  varchar(40);
desc student;

SELECT * from student where gongzhuoliang like '六%';
update student set zhuchezhibeng='5000元' where XMH=1;