Django - ValidationError “value must be an integer”

Question

I was recycling some of my code from an old project (Django 1.7) to use it in a new one (Django 1.8), so I get this Error every time I want to Login

It was working well in Django 1.7

For my models I'm using an AbstractBaseUser

models.py

class Student(AbstractBaseUser, models.Model):
    email = models.EmailField(max_length=50)
    user_id = models.CharField(max_length=8, null=False, editable=False, default=id_generator, primary_key=True)
    first_name = models.CharField(max_length=20)
    last_name = models.CharField(max_length=20)
    prom_code = models.CharField(max_length=8, null=False, default="")
    gender = (("M","Male"),("F","Female"),)
    gender = models.CharField(max_length=1, choices=gender, default="M", null=False)
    USERNAME_FIELD = 'email'

    @property
    def is_superuser(self):
        return False

    def has_perm(self, perm, obj=None):
        return False

    def has_module_perms(self, app_label):
        return False

    @property
    def is_staff(self):
        return False

    def save(self, **kwargs):
        if not self.user_id:
            self.user_id = id_generator()
            while Student.objects.filter(user_id = self.user_id).exists():
                self.user_id = id_generator()

        super(Student, self).save() 

I made a custom Authentication

auth_backend.py

from registration_app.models import Student
import md5    


class ClientAuthBackend(object):

    def authenticate(self, username=None, password=None):
        try:
            user = Student.objects.get(email=username)
            password_ver = md5.new(password).hexdigest()        
            if user.check_password(password_ver):
                return user
            else:
                print("Entre aqui")
                return None
        except Student.DoesNotExist:
            print("Entre aqui2")
            return None

    def get_user(self, user_id):
        try:
            user = Student.objects.get(user_id=user_id)
            if user is not None:
                return user
        except Student.DoesNotExist:
            return None

views.py

def user_login(request):
    args = {}
    form = LoginForm(request.POST)
    username = request.POST.get('email', '')
    password = request.POST.get('password', '')
    user = authenticate(username=username, password=password)

    if user is not None:
        print user.first_name + " ah iniciado session"
        login(request, user) #-----**Here is where i get the problem**-----
        return HttpResponseRedirect('/user/')
    else:
        print("El usuario no existe")

    args['form'] = form
    return render(request, 'user_student/login.html', args)

In my command prompt I can actually see the user getting logged in (it brings me the name of the user)

Answer 1

According to the Django documentation:

The Django admin is tightly coupled to the Django User object. The best way to deal with this is to create a Django User object for each user that exists for your backend (eg, in your LDAP directory, your external SQL database, etc.) You can either write a script to do this in advance, or your authenticate method can do it the first time a user logs in.

https://docs.djangoproject.com/en/1.11/topics/auth/customizing/

What happens is your having a non Numeric PK for the User, and Django doesn't like that. I had the same problem.

As stated in the documentation you should create a User for each authentication (if it doesn't exists yet) and change the get_user method in your ClientAuthBackend back to:

def get_user(self, user_id):
    try:
        return User.objects.get(pk=user_id)
    except User.DoesNotExist:
        return None

After I changed that, it all works smooth.

Answer 2

This error comes from your Django Session. I solved it using by

- python manage.py shell

At the shell, I ran

> from django.contrib.sessions.models import Session
> Session.objects.all().delete()

you can check the created session by running

Assuming the userid = '2b1189a188b44ad18c35e113ac6ceead'
s = Session.objects.get(pk='2b1189a188b44ad18c35e113ac6ceead')

you can read more about session here

I hope this helps.