1.創(chuàng)建一個(gè)新的表

create table if not exists goods_cates(id int unsigned key auto_increment,name varchar(40) not null) ;

2.把一個(gè)表的數(shù)據(jù)插入另一個(gè)表

insert into good_cates (name) values select cate_name from goods group by cate_name ;

3 同步表數(shù)據(jù)

update goods as g inner join goods_cates as c on g.cate_name = c.name set g.cate_name = c.id;

4 更改表結(jié)構(gòu)

alter table goods change cate_name cate_id int unsigned not null;

5 外鍵

alter table goods add foreign key (cate_id) references goods_cates(id);