select [distinct] [*] [列名,列名2] from 表名 [where 條件]
distinct: 去除重複的數據
--商品分類: 手機數碼, 皮靴箱包
1.分類ID
2.分類名稱
3.分類描述
Create table category (
cid int primary key auto_increment,
cname varchar(10),
cdesc varchar(30)
);
insert into category values(null, '手機數碼','電子產品,黑馬生產');
insert into category values(null, '皮靴箱包','江南皮革廠親情打造');
insert into category values(null, '香菸酒水','衡水老白乾');
insert into category values(null, '酸奶餅乾','君樂寶乳業');
insert into category values(null, '饞嘴零食','花生瓜子八寶粥');
select * form category;
select cname,cdesc from category;
--所有商品
1.商品ID
2.商品名稱
3.商品價格
4.商品數量
5.生產日期 (時間戳,默認當前時間)
6.商品分類ID
商品和商品分類: 所屬關係
create table product(
pid int primary key auto_increment,
pname varchar(10) ,
price double,
pdate timestamp,
cno int
);
insert into product values(null, '小米mix8',998,null,1);
insert into product values(null, '錘子',2888,null,1);
insert into product values(null, '阿迪王',99,null,2);
insert into product values(null, '老白乾',598,null,3);
insert into product values(null, '敬酒',298,null,3);
insert into product values(null, '小熊餅乾',1,null,4);
insert into product values(null, '衛龍辣條',3,null,5);