django - django 检索用户对象

Question

我有一个像这样的简单模型：

class Auction(models.Model):
    name = models.CharField()

class Item(models.Model):
    auction = models.ForeignKey(Auction)
    name = models.CharField()
    price = models.FloatField()

class Bid(models.Model):
    item = models.ForeignKey(Item)
    user = models.ForeignKey(User)
    price = models.FloatField()

用户对一个项目进行投标。知道用户只允许为每件商品出价一次。如果我有拍卖 ID，我能否获得在该拍卖中出价的所有用户对象（不是简单的用户名，例如 a values_list()）？

编辑：我也想避免使用'in'

Answer 1

users = User.objects.filter(bid__item__auction_id=auction_id)

Answer 2

It's probably possible to do it much easier, but this is the way I would try.

Add related names:

from django.db import models
from django.contrib.auth.models import User

class Auction(models.Model):
    name = models.CharField(max_length=20)

class Item(models.Model):
    auction = models.ForeignKey(Auction,related_name="items")
    name = models.CharField(max_length=20)
    price = models.FloatField()

class Bid(models.Model):
    item = models.ForeignKey(Item,related_name="bids")
    user = models.ForeignKey(User,related_name="bids")
    price = models.FloatField()

Now, if you have these:

a = Auction.objects.get(pk=auction_id)
users = set([]) #because there's no reason to have dupe users
for item in a.items.all():
    for bid in item.bids.all():
        users.add(bid.user)

Now, all the users with one or more bids in that auction is in the list