drop table cart_item;drop table cart_order;drop table cart_product;drop table cart_user;create table cart_user(	id integer primary key,	name varchar(32) not null,	password varchar(32) not null,	birthday date,	address varchar(512) not null,	postcode varchar(10) not null,	email varchar(32),	telephone varchar(32) not null);insert into cart_user values(1,'rmeng','820419','1988-1-1','ranmeng','100081','tarena@tarena.com.cn','62136369');create table cart_product(	id integer primary key,	name varchar(32) not null,	description varchar(64),	price double not null);insert into cart_product values(1,'pencil','pencil',2.00);insert into cart_product values(2,'pen','pen',5.00);insert into cart_product values(3,'rubber','rubber',1.00);insert into cart_product values(4,'notebook','notebook',2.00);insert into cart_product values(5,'gluewater','gluewater',5.00);insert into cart_product values(6,'pencilcase','pencilcase',10.00);insert into cart_product values(7,'ballpen','ballpen',2.00);create table cart_order(	id integer primary key,	cost double not null,	status integer not null,	user_id integer references cart_user(id));create table cart_item(	id integer primary key,	amount integer,	product_id integer references cart_product(id),	order_id integer references cart_order(id));