Unique foreign key pairs with Django

Question

I have three models: products, users, and reviews.

A review is linked to a product and a user as follows:

class Review(models.Model):
    product = models.ForeignKey(Product)    
    user = models.ForeignKey(User)
    review_text = models.TextField()
    creation_date = models.DateTimeField(auto_now_add=True)

I'd like to allow each user to submit only one review per product. What is the recommended way to achieve this? Through the model, through verification, or something else? I'm very new to Django/Python. Thanks.

Answer 1

Use unique_together to make sure that each user/product combination is unique:

class Review(models.Model):

  class Meta:

    unique_together = ['user', 'product']

  user = models.ForeignKey(User)
  product = models.ForeignKey(Product)