CODEWITHSUNDEEP
djangodatabase-design
infiniteloop
infiniteloop

Reputation: 2212

What's the "right way" to design Django models for this use case?

I'm slightly confused about what the "right way" is to design Django models for this particular use case.

I have models called Book, User, Rating. I'm designing an app that let users rate books.

Rating has a many-to-one relationship with user and a many-to-one relationship with Book. 

class User(models.Model):
    name = models.CharField(max_length=30)

class Book(models.Model):
    name = models.CharField(max_length=30)

class Rating(models.Model):
    user = models.ForeignKey(User,related_name=ratings)
    book = models.ForeignKey(Book,related_name=ratings)
    ...

With this design, I can't work out how to enforce the rule that a user can only rate each book once. I'm also not sure whether this is the right way to design models for this use case. So if I could get a few pointers in the right direction, it might help me avoid design flaws at this early stage.

Thanks in advance!

Upvotes: 2

Views: 345

Answers (1)

Brandon Taylor
Brandon Taylor

Reputation: 34553

You can use the unique_together Meta option on your Rating model: https://docs.djangoproject.com/en/1.3/ref/models/options/#unique-together

Upvotes: 5

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