TypeError: 'ModelBase' 对象在尝试使用排除时不可迭代

Question

I have the following two models:

class Listings(models.Model):
    CATEGORY = [
    ("Miscellaneous", "Miscellaneous"),
    ("Movies and Television", "Movies and Television"),
    ("Sports", "Sports"),
    ("Arts and Crafts", "Arts and Crafts"),
    ("Clothing", "Clothing"),
    ("Books", "Books"),
]
    title = models.CharField(max_length=64)
    description = models.CharField(max_length=500)
    bid = models.DecimalField(max_digits=1000000000000, decimal_places=2)
    image = models.URLField(null=True, blank=True)
    category = models.CharField(max_length=64, choices=CATEGORY, default=None)
    user = models.ForeignKey(User, on_delete=models.CASCADE, default="")

class CloseListing(models.Model):
    listings = models.ForeignKey(Listings, on_delete=models.CASCADE, default="")
    user = models.ForeignKey(User, on_delete=models.CASCADE, default="")

I want to be able to query through all the objects of every listing that is not in the CloseListing model. How can I do this?

I tried the code in the answer, and I am still not able to query through all the objects of every listing not in the CloseListing model. I think it might have to do with how I am saving the model. The following code is the part of the view that deals with the CloseListing model.

def index(request):
    listings = Listings.objects.all().exclude(id__in=CloseListing)
    return render(request, "auctions/index.html",{
        "listings": Listings.objects.all()
    })

error message: TypeError: 'ModelBase' object is not iterable because of listings = models.ForeignKey(Listings, on_delete=models.CASCADE, default="") .

closeListing part of views.py

@login_required(login_url='login')
def listing(request, id):
    #gets listing
    listing = get_object_or_404(Listings.objects, pk=id)
    sellar = listing.user

    #close listing code
    if sellar == request.user:
        closeListingButton = True
    else: 
        closeListingButton = False
    closeListing = ''
    try:
        has_closed = get_list_or_404(CloseListing, Q(
            user=request.user) & Q(listings=listing))
    except:
        has_closed = False
    if has_closed:
        closeListing = False
    else: 
        closeListing = True

   if request.method == "POST":
       #close listing code
        if request.POST.get('close'):
          CloseListing.objects.create(user=request.user,
 listings=listing)
            closeListing = True
            closeListingButton = False
            add_or_remove_watchlist = True
            winning_bid = Bids.objects.aggregate(Max('bid'))
            winning_bid = Bids.objects.latest('bid')
            winner = winning_bid.user
            return render(request, "auctions/listing.html",{
                        "auction_listing": listing,
                        "comments": comment_obj,
                        "bids": bid_obj,
                        "closeListingButton": closeListingButton,
                        "closeListing": closeListing,
                        "closedMessage": "This listing is closed.",
                        "winner": winner
            })
            return render(request, "auctions/listing.html",{
                 "auction_listing": listing,
                 "closeListingButton": closeListingButton, 
                 "closeListing": closeListing
            })

Answer 1

You should not query directly through model, which is CloseListing , you can first filter all close listings from CloseListing model then exclude all those listings which are in CloseListing by exclude() .

views.py

def index(request):
    close_listings = CloseListing.objects.values('listings')
    listings=Listings.objects.exclude(id__in=close_listings)
    return render(request, "auctions/index.html",{
        "listings": listings
    })

I'd recommend you to add __str__ in Listing model as:

class Listings(models.Model):
    CATEGORY = [
        ("Miscellaneous", "Miscellaneous"),
        ("Movies and Television", "Movies and Television"),
        ("Sports", "Sports"),
        ("Arts and Crafts", "Arts and Crafts"),
        ("Clothing", "Clothing"),
        ("Books", "Books"),
    ]
    title = models.CharField(max_length=64)
    description = models.CharField(max_length=500)
    bid = models.DecimalField(max_digits=1000000000000, decimal_places=2)
    image = models.URLField(null=True, blank=True)
    category = models.CharField(max_length=64, choices=CATEGORY, default=None)
    user = models.ForeignKey(User, on_delete=models.CASCADE, default="")

    def __str__(self) -> str:
        return f'{self.title}'

By adding __str__ you would see instances title instead of objects.