python - Value Error. Cannot assign query set. It must be an instance

Question

I want to create object in my comment model. It's my Reply model to a post.

class Reply(MPTTModel):
    post = models.ForeignKey(Post, on_delete=models.CASCADE)

    detail = models.CharField(max_length=50, null=True, blank=True, unique=True)

    pub_date = models.DateTimeField(auto_now_add=True)
    last_edited = models.DateTimeField(auto_now=True)
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    class MPTTMeta:
        order_insertion_by = ['name']

It's my view function for reply.

def post_detail(request,id,**kwargs):
    post = Post.objects.all().filter(id=id)
    comment = CommentReply.objects.filter(post=id)
    context = {'post': post, 'comment': comment}
    if request.method == 'POST':
        comments = request.POST.get('comment')
        Reply.objects.create(
                post=post, detail=comments, author = request.user)
    else:
        return render(request, 'khalidblog_app/full_detail.html', context)

    return render(request,'khalidblog_app/full_detail.html',context)

I'm using for loop in my template:

{% for post in post %}
    <img alt='' src='{{ post.image.url }}' class='avatar avatar-80 photo' height='80' width='80' />
    <div class="eltd-author-description-text-holder">
        <h5 class="eltd-author-name"> {{post.author}} </h5>
    <div class="eltd-author-text">
        <p>{{post.title}}</p>
    </div>
    <div class="eltd-author-text">
        <p>{{post.content}}</p>
        <hr>
    </div>
{%endfor%}

When I run this view function It shows a value error as follows.

Cannot assign "<QuerySet [<Post: Author : zorainTiTleFirst PostDated :2021-01-17 16:27:47.043869+00:00>]>": "Reply.post" must be a "Post" instance.

How I can set the forignkey(Post) in this reply model using this view function?

question from:https://stackoverflow.com/questions/65943713/value-error-cannot-assign-query-set-it-must-be-an-instance

Answer 1

On the very first line of your function, you are using .filter() method which returns QuerySet (List of Objects in short), where you should have ideally used .get() method. .get() returns a single object which the assignment on line 6 actually expects.