CREATE TABLE khachhang( ID_khachhang VARCHAR(10), NAME_khachhang VARCHAR(255) ); CREATE TABLE hoadon( ID_hoadon INT, ID_khachhang VARCHAR(10), DATE_hoadon date ); INSERT INTO khachhang VALUES ("Kh001","Khach Hang 001"); INSERT INTO khachhang VALUES ("Kh002","Khach Hang 002"); INSERT INTO khachhang VALUES ("Kh003","Khach Hang 003"); INSERT INTO khachhang VALUES ("Kh004","Khach Hang 004"); INSERT INTO khachhang VALUES ("Kh005","Khach Hang 005"); INSERT INTO hoadon (ID_hoadon,ID_khachhang, DATE_hoadon) VALUES (101,"Kh005","2015-03-03"); INSERT INTO hoadon (ID_hoadon,ID_khachhang, DATE_hoadon) VALUES (102,"Kh002","2015-07-09"); INSERT INTO hoadon (ID_hoadon,ID_khachhang, DATE_hoadon) VALUES (103,"Kh003","2015-10-12");