CODEWITHSUNDEEP
pythondjangodjango-queryset
HS Park
HS Park

Reputation: 63

How to get user queryset who commented to certain post in Python, Django?

I would like to get a user queryset who commented in certain post. Assume that there is a post(id=3), and there 8 people commented on it. I want to notify something to 8 people, so I want to get 8 people's queryset(user objects). How can I do it?

I have model User, Post, and Comment.

For example,

User.objects.get(comment__Post.objects.filter(id='3'))

like this way. (of course, the upper doesn't work)

Help me!

User model is Django User model.

class Post(models.Model):
    post_id = models.CharField('username', max_length=150)
    ...

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    com_id = models.CharField('username', max_length=150)
    ....

Upvotes: 0

Views: 1261

Answers (2)

aprasanth
aprasanth

Reputation: 1099

Ideally your models should look like the following

class Post(models.Model):
    posted_by = models.ForeignKey(User, on_delete=models.CASCADE)
    ...

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    comment = models.CharField(max_length=100)
    commented_by = models.ForeignKey(User, on_delete=models.CASCADE)

And your requirement can be achieved through the following query

post = Post.objects.get(id=3)
user_ids = list(Comment.objects.filter(post=post).values_list('user__id', flat=True))

This will return the list of user ids

If you need queryset,

users = User.objects.filter(id__in=user_ids)

Upvotes: 1

Alessio Ferri
Alessio Ferri

Reputation: 345

In my opinion you should add a OneToOneField to the model Comment and to the model Post that relate to the User model like this:

from django.conf import settings
...
class Post(models.Model):
    ...
    user = models.OneToOneField(settings.User, related_name="posts")
    ...

class Comment(models.Model):
    ...
    user = models.OneToOneField(settings.User, related_name"comments")
    post = models.ForeignKey(Post, related_name="post_comments")
    ...

The for your queryset you will be able to do:

User.objects.get(posts__id=3)
for comments in Comment.objects.get(post_comments__id=3):
    comments.user # this are the user that commented on a certain post.

Upvotes: 1

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