Mysql 语句

show databases;
create database first;
drop database first;
use example;
create table example0(
 id int primary key auto_increment,
 name varchar(20)
 );
show tables;
describe example0;
show create table example1 \G
primary key,

constraint c_fk foreign key(stu_id,course_id) references exma2(stu_id,course_id)

unique
math float default 0

alter table ex0 rename ex1;
alter table ex0 modify sex int(4);
alter table ex0 change id stu_id int;
alter table ex0 add age int not null;
alter table ex0 add id int primary key first;
alter table ex0 add address varchar(30) not null after name;
alter table ex0 drop sex;
alter table ex0 modify address varchar(30) after name;
alter table ex0 modify address varchar(30) first;
alter table ex0 drop foreign key c_fk;
drop table ex0;

insert into 表名 values(, , , );

select * from 表名；
select * from 表名 where id in(1000,1001);
select * from 表名 where age between 18 and 20;
select * from biao where name like "李明";
select * from biao where name like "李%";
select * from biao where name like "%李%";
select * from b where name like "李_";
select * from b where name not like "李%";
select * from ex0 order by id asc;
select * from ex0 order by age desc;
select avg(math),avg(English),avg(sum) from a1;
select id,name,max(sum) from a1;
select id,name,sex,max(sum) from a1 group by sex;

update tab_name set col_name1="",col_name2=" " where name="" order by 
update tab_name set sum=math+English;

delete tab_name from tab_name where id=1005;