from django.db import models

class School(models.Model):

    name = models.CharField(max_length=100)

class Parent(models.Model):

    name = models.CharField(max_length=100)

class Child(models.Model):

    mother = models.ForeignKey(Parent, models.CASCADE, related_name="mothers_children")

    father = models.ForeignKey(Parent, models.CASCADE, related_name="fathers_children")

    school = models.ForeignKey(School, models.CASCADE)

    name = models.CharField(max_length=100)

class Poet(models.Model):

    name = models.CharField(max_length=100)

    def __str__(self):

        return self.name

class Poem(models.Model):

    poet = models.ForeignKey(Poet, models.CASCADE)

    name = models.CharField(max_length=100)

    class Meta:

        unique_together = ("poet", "name")

    def __str__(self):

        return self.name