create database yen use yen create table phanloai ( maloai nchar(50) not null primary key, tenloai nchar(50) not null, ) create table nhacungcap ( maNCC nchar(50) not null primary key, tenNCC nchar (50) not null, diachi nchar(50) not null, dienthoai numeric null, ) create table khachhang ( maKH nchar(50) not null primary key, tenKH nchar(50) not null, diachi nchar(50) not null, dienthoai numeric null, ) create table hanghoa ( maHH nchar(50) not null primary key, tenHH nchar(50) not null, donvitinh nchar(50) not null, maloai nchar(50) not null, ) create table bangbaogia ( maNCC nchar(50) not null primary key, maMH nchar(50) not null, giaban numeric not null, ) create table cungcap ( maNCC nchar(50) not null primary key, maHH nchar(50)not null, ngay date not null, soluong numeric not null, ) create table hoadonbanhang ( maHD nchar(50) not null primary key, maKH nchar(50) not null, maHH nchar(50) not null, ngay date not null, soluong numeric not null, dongia numeric not null, )