数据库

create database school;

use school

create table student(

 cno int primary key, cname varchar(20), gender int(1),  grade float

);

desc student;

insert into student(cno,cname,gender,grade)values(101,"math",0,95.5);

insert into student(cno,cname,gender,grade)values(102,"english",1,85.0);

insert into student(cno,cname,gender,grade)values(103,"chinese",0,73.5);

select *from student;

select cno,grade from studnet;

update student set grade=89.0 where grade=73.5;

create table teacher(

 tno int primary key,

 tname varchar(15),

 course varchar(15),

 room int);

show create table teacher\G;

alter table teacher change tno tno int auto_increment;

insert into teacher values(null,"jim","math",405),(null,"tom","english",101),(null,"marry","chinese",306);

select *from teacher;

delete from teacher where tno=1;

delete from teacher;

drop table teacher,student;

drop database school;