Django foreign key form save

Question

EDIT: I have since solved the problem (with help from stackoverflow and IRC, but I have to wait two days before I can mark this question as solved. See my reply below to see the solution!

I am currently working an a 'IMDB' clone for me and my friends to use. The idea is that each of us gets an account and can either submit new movies or vote on already submitted ones. These movies are sorted by rating and users can access the detail view to see the individual reviews.

To achieve this I'm using foreign keys in my models.py - one for the movie entries (with information like director, title, etc) and one for the individual votes. The latter one uses foreign keys to fetch the movies title and the user that submitted the review.

However when testing the form that submits reviews I encountered the 'NOT NULL constraint failed: list_vote.voter_id_id' error. When browsing through the error page I discovered that the foreignkey values are not submitted to the database

params: [None, None, 9.0]
query: ('INSERT INTO "list_vote" ("movie_id_id", "voter_id_id", "rating") VALUES (?, ' '?, ?)') 
self  <django.db.backends.sqlite3.base.SQLiteCursorWrapper object at 0x7f77b8907dc8>

Yet, when I browse the error page for the local vars at the moment of the 'post.save()' command the missing variables seem to be there

entry: <Entry: Starwars 4>
form: <VoteForm bound=True, valid=True, fields=(rating)>
movie_id: 'Starwars 4'
post: <Vote: Vote object>
request: <WSGIRequest: POST '/vote/starwars-4/'>
slug: 'starwars-4'
voter_id    : <SimpleLazyObject: <User: admin>>

If I add the ' movie_id' and ' user_id' values to my modelform (in the 'fields' variable) the form actually works. (though this is not what I want, as there could potentially be hundreds of movies in this database, making selection rather difficult. And right now, any user can pretend to be anyone)

I'm probably missing something very obvious, but for the life of me I cannot figure out what I'm doing wrong. The models, forms etc are based on both the Django_girls tutorial (where they work) and the 'Hello WebApp' book (though foreign keys are not used in this book)

Does anyone know what I'm doing wrong here?

These are the models used:

class Entry(models.Model):
  movie = models.CharField(max_length=255)
  director = models.CharField(max_length=255)
  total_votes = models.IntegerField(default=0)
  rating = models.FloatField(default=0) 
  length = models.IntegerField(default=0)
  year = models.IntegerField(default=0)
  added_by = models.ForeignKey(User)
  slug = models.SlugField(unique=True)

  def __str__(self):
      return self.movie

########################
 Vote-model:
 ########################

class Vote(models.Model):

  class Meta:
      unique_together = (('voter_id','movie_id'),)

  movie_id = models.ForeignKey(Entry)
  voter_id = models.ForeignKey(User)
  rating = models.FloatField(validators=[MinValueValidator(0), MaxValueValidator(10)])

This is my form.py:

class VoteForm(ModelForm):
  class Meta:
      model = Vote
      fields = ('rating',)

This is the relevant function form the view.py:

def lets_vote(request, slug):
  entry = Entry.objects.get(slug=slug)


  if request.method == "POST":
      form = VoteForm(request.POST)
      if form.is_valid():
          voter_id = request.user
          movie_id = Entry.objects.get(slug=slug).movie
          post = form.save(commit=False)
          post.save()
          return redirect('/movies/')

  else:
      form = VoteForm()

  return render(request, 'list/lets_vote.html', {'entry':entry, 'form':    form})

Last but not least: the voteform from the html page:

<form role="form" action="" method="post">
{% csrf_token %}
{{ form.as_p }}
<button type="submit">Submit</button>
</form>
{% endblock %}

Answer 1

I posted this question on the Django IRC as well and somebody there helped me solve the problem!

I originally made two mistakes:

1. I added a '_id' in my models. This is already done so automatically, so the variables in my database were actually called 'movie_id_id'. I've since removed the superfluous '_id'.

2. The '.movie' in the following line was unnecessary.

   post.movie = Entry.objects.get(slug=slug).movie

The correct, working view is as follows:

def lets_vote(request, slug):
  entry = Entry.objects.get(slug=slug)
  form = VoteForm(request.POST)

  if request.method == "POST":
      if form.is_valid():

          post = form.save(commit=False)
          post.voter = request.user
          post.movie = Entry.objects.get(slug=slug)
          post.save()
          return redirect('/movies')

I only needed the actual instance, but the rest of @Alasdair his suggestions were correct. Thank you @Alasdair and Flobin from IRC!