Error adding comment?

Question

Django

If you try to add a comment to a post through the form, it gives the following error.
IntegrityError at /post/7/comment/
NOT NULL constraint failed: blog_comment.post_id
But if you write a comment through the admin panel, then there are no errors and everything is ok. By the way, after I added a comment, then the link to the comment form disappears on the page. Why?

#models.py
class Comment(models.Model):
    post = models.ForeignKey('blog.Post', on_delete=models.CASCADE, related_name='comments')
    author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    text = models.TextField(null=True, blank=True)
    pub_date = models.DateTimeField(default=timezone.now)

    def __str__(self):
        return self.text

#views.py
def add_comment(request, pk):
    post = get_object_or_404(Post, pk=pk)
    if request.method == 'POST':
        add_comment_form = CommentForm(request.POST)
        if add_comment_form.is_valid():
            comment_form = add_comment_form.save(commit=False)
            comment_form.author = request.user
            comment_form.save()
            return redirect('post_detail', pk=post.pk)
    else:
        add_comment_form = CommentForm()
    return render(request, 'blog/add_comment.html', {'add_comment_form': add_comment_form})

Answer 1

The question is clearly incomplete without code CommentForm. Either in it or in view, you must fill in all the fields that are required in the model (hint: postis a required field in the model Comment).