Django, save ModelForm

Question

I have created a model Student which extends from the Django User and is a foreign key to another model while it has an integer field called year. What i'm trying to do is to save a form, which has 2 fields. The one is the course id and the another one is the the integer field year. When I'm clicking submit, i'm getting an error Cannot assign "u'2'": "Student.course" must be a "Course" instance.

models.py

class Student(models.Model):     user = models.OneToOneField(User)     course = models.ForeignKey(Course)     year = models.IntegerField(validators=[MinValueValidator(1),                                            MaxValueValidator(7)]) 

view.py

def step3(request):     user = request.user     if request.method == 'POST':         form = SelectCourseYear(request.POST)         if form.is_valid():             form.save()             return render_to_response("registration/complete.html", RequestContext(request))     else:         form = SelectCourseYear()     return render(request, 'registration/step3.html',) 

forms.py

class SelectCourseYear(forms.ModelForm):     course = forms.CharField()     year = forms.IntegerField(required=True)      class Meta:         model = Student         fields = ['user', 'course', 'year'] 

Answer 1

You dont need to redefine fields in the ModelForm if you've already mentioned them in the fields attribute. So your form should look like this -

class SelectCourseYear(forms.ModelForm):     class Meta:         model = Student         fields = ['course', 'year'] # removing user. we'll handle that in view 

And we can handle the form with ease in the view -

def step3(request):     user = request.user     if request.method == 'POST':         form = SelectCourseYear(request.POST)         if form.is_valid():             student = form.save(commit=False)             # commit=False tells Django that "Don't send this to database yet.             # I have more things I want to do with it."              student.user = request.user # Set the user object here             student.save() # Now you can send it to DB              return render_to_response("registration/complete.html", RequestContext(request))     else:         form = SelectCourseYear()     return render(request, 'registration/step3.html',)