Django - IntegrityError - Not null constraint

Question

When the field of my form is empty, I have this error :

IntegrityError at /inscription NOT NULL constraint failed: le_site_inscrit.age

My models :

class Inscrit(models.Model):
    user = models.OneToOneField(User)
    age = models.IntegerField(max_length=2, null=True, default=None)

My form in forms.html :

class inscriptionForm(forms.Form):
    mail = forms.EmailField(max_length=100)
    firstname = forms.CharField()
    username = forms.CharField()
    age = forms.IntegerField(required=False)
    mdp = forms.CharField(widget=forms.PasswordInput)

My views :

def inscription(request):
    error = False
    if request.method == "POST":
        form = inscriptionForm(request.POST)
        if form.is_valid():
            mail = form.cleaned_data["mail"]
            mdp = form.cleaned_data["mdp"]
            username = form.cleaned_data["username"]
            userfirstname = form.cleaned_data["firstname"]
            age = form.cleaned_data["age"] or None
            u = User.objects.create_user(username,mail,mdp)
            u.first_name = userfirstname
            u.save()
            inscrit = Inscrit()
            inscrit.user = u
            if age is not None :
                inscrit.age = age
            inscrit.save()
            return redirect(reverse(home))
        else :
            error = True
    else :
        form = inscriptionForm()
    return render(request,"zouya/inscription.html",locals())

Thanks

Answer 1

Add blank=True to your model field definition:

class Inscrit(models.Model):
    user = models.OneToOneField(User)
    age = models.IntegerField(max_length=2, null=True, blank=True, default=None)