Generate a random alphanumeric string as a primary key for a model

Question

I would like a model to generate automatically a random alphanumeric string as its primary key when I create a new instance of it.

example:

from django.d         


        

Answer 1

Try this:

The if statement below is to make sure that the model is update able.

Without the if statement you'll update the id field everytime you resave the model, hence creating a new model everytime

from uuid import uuid4
from django.db import IntegrityError

class Book(models.Model):
    id = models.CharField(primary_key=True, max_length=32)

    def save(self, *args, **kwargs):
        if self.id:
            super(Book, self).save(*args, **kwargs)
            return

        unique = False
        while not unique:
            try:
                self.id = uuid4().hex
                super(Book, self).save(*args, **kwargs)
            except IntegrityError:
                self.id = uuid4().hex
            else:
                unique = True