from django.db import models class Author(models.Model): name = models.CharField(max_length=20) age = models.IntegerField(null=True) birthdate = models.DateField(null=True) average_rating = models.FloatField(null=True) def __str__(self): return self.name class Article(models.Model): author = models.ForeignKey(Author, on_delete=models.CASCADE) class MySQLUnixTimestamp(models.Model): timestamp = models.PositiveIntegerField()