如何从Django模型中排除值？

Question

我正在尝试从观察列表中排除一个项目，但它不起作用

我的代码：

def watchlist(request, page_id):
    items = Watchlist.objects.all()
    item = Auction_listings.objects.get(pk=page_id)

    if request.method == "POST":
        if item_id not in items:
            add = Watchlist(auction=item)
            add.save()
        else:
            remove = Watchlist.objects.get(auction=item)
            remove.delete()
            
    return render(request, "auctions/watchlist.html", {
        "items": Watchlist.objects.all()
    })

Answer 1

您可以检查queryset中是否存在该项，然后从那里开始

def watchlist(request, page_id):
    items = Watchlist.objects.all()
    item = Auction_listings.objects.get(pk=page_id)

    if request.method == "POST":
        if not items.filter(auction=item).exists():
            add = Watchlist(auction=item)
            add.save()
        else:
            remove = Watchlist.objects.get(auction=item)
            remove.delete()
            
    return render(request, "auctions/watchlist.html", {
        "items": Watchlist.objects.all()
    })