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pythondjangodjango-modelsdjango-database

Use new subclass with already in use database in django

I'm trying to create a customized User class inheriting from django User. Problem is I already have some users in database which can not be deleted whatsoever and also I have another class (let's say reports) which have a foreignkey to User. My question is: Is there any way to create my new User class and keep the old data too?
thanks in advance.

Solution

  • You can create related model that links back to User. This is a common approach if you have different types of users, but there are also other use cases.

    class SpecialUserProfile(models.Model):
    user = models.OneToOneField(User, null=True, blank=True, on_delete=models.SET_NULL)
    special_feature = models.CharField(max_length=100, null=True, blank=True)
    etc.

    What you also need to do is create this profile, when new user is added to User. You can do this with post_save signal.

    @receiver(post_save, sender=User)
def create_special_user_profile(sender, instance, created, **kwargs):

    if created:
        SpecialUserProfile.objects.create(user=instance)

    You create profiles for existing user with a command or write and run a temporary function that does that for existing users in User.

    Now you can use ORM in the sense of user.specialuserprofile.special_feature.

    This way you'll keep using User model as a base, it won't mess with build-in user related functionalities, won't have think about new and old users and you can use this new model for any additional information about users.