django - "IntegrityError. NOT NULL constraint failed: blog_comment.post_id "代表什么？

Question

我已经在我的应用程序中添加了一个 Comment 模型，但是当提交表单时，弹出这个错误:

NOT NULL 约束失败:blog_comment.post_id

这是模型.py:

class Post(models.Model):
    title = models.CharField(max_length=100, null=True, blank=True)
    caption = models.CharField(max_length=100, null=True, blank=True)
    image = models.ImageField(upload_to='post_pics/', null=True, blank=True)
    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('post-detail', kwargs={'pk': self.pk})

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE, related_name='comments')
    text = models.TextField(null=True)
    date_posted = models.DateTimeField(default=timezone.now)

    def __str__(self):
        return self.text

    def get_absolute_url(self):
        return reverse('post-detail', kwargs={'pk': self.pk})

这是在 views.py 中创建评论的部分:

class AddCommentView(LoginRequiredMixin, CreateView):
    model = Comment
    fields = ['text']

    def form_valid(self, form):
        form.instance.author = self.request.user
        return super().form_valid(form)

我的表格.py:

class CommentForm(forms.ModelForm):

    class Meta:
        model = Comment
        fields = ['text']

html 格式:

    <div class="content-section">
        <form method="POST">
            {% csrf_token %}
            <fieldset class="form-group">
                <legend class="border-bottom mb-4">New Comment</legend>
                {{ form|crispy }}
            </fieldset>
            <div class="form-group">
                <button class="btn btn-outline-info" type="submit">Publish</button>
            </div>
        </form>
    </div>

Answer 1

您必须为 post 设置值，因为它是一个外键。在 form_valid 中，您应该定义 post = Post.objects.get(id=current_post_id) 并且您可以从 url 获取 current_post_id 或将其接收为一个参数。然后赋值:form.instance.post = post