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()