Test Inventory Database Models

inventory_models.py

class Product(models.Model):
    profile = models.ForeignKey('accounts.Profile', null=True,
                                blank=True, on_delete=models.CASCADE)
    name = models.CharField(max_length=180)


class ProductOption(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    nr = models.IntegerField(default=0)
    name = models.CharField(max_length=20, null=False, blank=False)

    def __str__(self):
        return f'{self.product}: {self.name}'

    class Meta:
        unique_together = ('nr', 'product')


class ProductOptionValue(models.Model):
    option = models.ForeignKey(ProductOption, on_delete=models.CASCADE)
    value = models.CharField(max_length=20, null=False, blank=False)

    def __str__(self):
        return f'{self.option.name}: {self.value}'


class ProductSKUValue(models.Model):
    product = models.ForeignKey(Product, on_delete=models.CASCADE)
    option = models.ForeignKey(ProductOption, on_delete=models.CASCADE)
    option_value = models.ForeignKey(ProductOptionValue, on_delete=models.CASCADE)
    sku = models.CharField(max_length=40, null=False, blank=False, unique=True)


    def __str__(self):
        return f'{self.product.name} - {self.option_value}: {self.sku}'

    class Meta:
        unique_together = ('product', 'sku', 'option', 'option_value')