Django使用内置的User模型时，如何按名称优雅地过滤Friend对象？

Question

I am learning by building and have a little FriendShip class. In one of my views, I want to filter the FriendShips such that my user is shown a list of all friendships he or she is involved in.

To give you an idea, something like this that has valid syntax:

relevant_friends_list = FriendShip.objects.filter(request.user.username == creator || request.user.username == friend)

But you can't just do that since friend and creator are user objects.

models.py

from django.contrib.auth.models import User
class FriendShip(models.Model):
    created = models.DateTimeField(auto_now_add=True, editable=False)
    creator = models.ForeignKey(User, related_name="friendship_creator_set")
    friend = models.ForeignKey(User, related_name="friend_set")
    def __str__(self):
        return self.creator.username + " | " + self.friend.username

If I were to mimic the tutorial, I would add properties like creator_name = models.charField(...) and set that equal to User.username or something. But that sounds like I'm overthinking things, and it just feels like django would have a minimal-line solution. Thanks for your time

Answer 1

You are indeed overthinking. You can filter by model objects, and since you want an OR operation, you can use Q objects like so:

from django.db.models import Q

user = request.user
conditions = Q(creator=user) | Q(friend=user)
relevant_friends_list = FriendShip.objects.filter(conditions)

Note that request.user is only available inside a view where the request object is available.