CREATE TABLE MAYTINH
(
  HANG VARCHAR(20),
  CPU VARCHAR(10),
  RAM INT,
  DOPHANGIAI CHAR(10),
  DUNGLUONG INT,
  PHANKHUC VARCHAR(15),
  BAOHANH INT,
  MAMAY VARCHAR(8) NOT NULL,
  PRIMARY KEY (MAMAY)
);

CREATE TABLE NHANVIEN
(
  HOTEN VARCHAR(30),
  MANHANVIEN VARCHAR(8) NOT NULL,
  NGAYSINH DATE NOT NULL,
  GIOITINH ,
  HESOLUONG FLOAT,
  PRIMARY KEY (MANHANVIEN)
);

CREATE TABLE KHACHHANG
(
  MAKH VARCHAR(8) NOT NULL,
  SDT VARCHAR(10),
  HOTEN VARCHAR(30),
  DIACHI VARCHAR(50),
  PRIMARY KEY (MAKH)
);

CREATE TABLE HOADON
(
  MAHOADON VARCHAR(8) NOT NULL,
  NGAYBAN DATE,
  MAKH VARCHAR(8) NOT NULL,
  MANHANVIEN VARCHAR(8) NOT NULL,
  PRIMARY KEY (MAHOADON),
  FOREIGN KEY (MAKH) REFERENCES KHACHHANG(MAKH),
  FOREIGN KEY (MANHANVIEN) REFERENCES NHANVIEN(MANHANVIEN)
);

CREATE TABLE PHIEUNHAP
(
  MAPHIEUNHAP VARCHAR(8) NOT NULL,
  NGAYNHAP DATE,
  NHACUNGCAP VARCHAR(30),
  MANHANVIEN VARCHAR(8) NOT NULL,
  PRIMARY KEY (MAPHIEUNHAP),
  FOREIGN KEY (MANHANVIEN) REFERENCES NHANVIEN(MANHANVIEN)
);

CREATE TABLE Chua
(
  SOLUONGBAN INT NOT NULL,
  GIABAN INT NOT NULL,
  MAHOADON VARCHAR(8) NOT NULL,
  MAMAY VARCHAR(8) NOT NULL,
  PRIMARY KEY (MAHOADON, MAMAY),
  FOREIGN KEY (MAHOADON) REFERENCES HOADON(MAHOADON),
  FOREIGN KEY (MAMAY) REFERENCES MAYTINH(MAMAY)
);

CREATE TABLE Co
(
  SOLUONGNHAP INT NOT NULL,
  DONGIANHAP INT NOT NULL,
  MAPHIEUNHAP VARCHAR(8) NOT NULL,
  MAMAY VARCHAR(8) NOT NULL,
  PRIMARY KEY (MAPHIEUNHAP, MAMAY),
  FOREIGN KEY (MAPHIEUNHAP) REFERENCES PHIEUNHAP(MAPHIEUNHAP),
  FOREIGN KEY (MAMAY) REFERENCES MAYTINH(MAMAY)
);