from django.db import models class Sale(models.Model): customer = models.CharField(max_length=100) date = models.DateField("Date") phone = models.CharField(max_length=13) description = models.CharField(max_length=255) class SaleLine(models.Model): sale = models.ForeignKey(Sale, on_delete=models.CASCADE) product = models.CharField(max_length=100) quantity = models.IntegerField(null=True) unit_price = models.DecimalField(max_digits=9, decimal_places=2) description = models.CharField(max_length=255)