IntegrityError at /tickets/1/comments/new/ NOT NULL constraint failed: comments_comment.ticket_id

Using Django Mystery Errors
1

Getting an integrity error when creating a separate comments app for my ticket project. Not sure why, I have already assigned the logged in user as author in the get_absolute_url method on my Comment object and so now I’m not sure on how to proceed. Any help is much appreciated

Here is my comment model

models.py

class Comment(models.Model):
    ticket = models.ForeignKey(Ticket, related_name='comments', on_delete=models.CASCADE)
    title = models.CharField(max_length=20)
    content = models.TextField()
    date_posted = models.DateTimeField(default=timezone.now)
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    
    def __str__(self):
        return self.title
    
    def get_absolute_url(self):
        return reverse('tickets: ticket-detail', kwargs={'pk': self.ticket_id})

Here is my views.py

class CommentCreateView(LoginRequiredMixin, CreateView):
    redirect_field_name = 'tickets/ticket_detail.html'
    model = Comment
    fields = ['title', 'content']

    def form_valid(self, form):
        form.instance.post_id = self.kwargs['pk']
        form.instance.author = self.request.user
        return super().form_valid(form)

Traceback

Django Version: 4.0.1
Python Version: 3.10.0
Installed Applications:
['tickets.apps.TicketsConfig',
 'users.apps.UsersConfig',
 'comments.apps.CommentsConfig',
 'crispy_forms',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback (most recent call last):
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)

The above exception (NOT NULL constraint failed: comments_comment.ticket_id) was the direct cause of the following exception:
  File "C:\Users\mikha\bug_env\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\views\generic\base.py", line 69, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\contrib\auth\mixins.py", line 71, in dispatch
    return super().dispatch(request, *args, **kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\views\generic\base.py", line 101, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\views\generic\edit.py", line 174, in post
    return super().post(request, *args, **kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\views\generic\edit.py", line 144, in post
    return self.form_valid(form)
  File "C:\Users\mikha\issuetracker\comments\views.py", line 38, in form_valid
    return super().form_valid(form)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\views\generic\edit.py", line 127, in form_valid
    self.object = form.save()
  File "C:\Users\mikha\bug_env\lib\site-packages\django\forms\models.py", line 466, in save
    self.instance.save()
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\base.py", line 743, in save
    self.save_base(using=using, force_insert=force_insert,
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\base.py", line 780, in save_base
    updated = self._save_table(
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\base.py", line 885, in _save_table
    results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\base.py", line 923, in _do_insert
    return manager._insert(
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\query.py", line 1301, in _insert
    return query.get_compiler(using=using).execute_sql(returning_fields)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\models\sql\compiler.py", line 1441, in execute_sql
    cursor.execute(sql, params)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 99, in execute
    return super().execute(sql, params)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 67, in execute
    return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 76, in _execute_with_wrappers
    return executor(sql, params, many, context)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 80, in _execute
    with self.db.wrap_database_errors:
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\utils.py", line 90, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\utils.py", line 85, in _execute
    return self.cursor.execute(sql, params)
  File "C:\Users\mikha\bug_env\lib\site-packages\django\db\backends\sqlite3\base.py", line 416, in execute
    return Database.Cursor.execute(self, query, params)

Exception Type: IntegrityError at /tickets/1/comments/new/
Exception Value: NOT NULL constraint failed: comments_comment.ticket_id
2

Look at your error message:

Where is the value for the ticket field in your new Comment model supposed to be coming from?

3

From my Ticket Model? So is the issue coming from my urls.py file for the Comments app?

4

No.

You’re trying to create an instance of Comment.

Comment has these five fields:

Your form has defined form fields for title and content.

Your form_valid method is setting author.

Your date_posted field has a default.

This accounts for four of the five fields.

You are not setting the ticket field - therefore, it’s null. However, the model field is not defined with null=True, therefore, you’re getting this error.