create table ceyan(ID int not null auto_increment,
name varchar(20), primay key (ID));
insert into ceyan(name) values('wei xie'),('chunjiezhao'),('fei dou');
插入的值數據庫會自動給他們編號;
對已經存在的表articles想修改字段arti_ID爲auto_increment必須首先將他定義成primary key,再設置auto_increment;
alter table articles modify arti_ID int not null;
alter table articles add primary key arti_ID;
alter table articles modify arit_ID int not null auto_increment;