我正在使用 Django 开发拍卖网站。我正在尝试显示 Last_bid 字段的数据，该字段使用外键连接到投标表。我尝试了很多方法，但都没有成功。models.py 文件是：
from django.contrib.auth.models import AbstractUser
from django.db import models
from django.db.models.base import Model
from django.db.models.deletion import CASCADE
from django.db.models.fields import CharField
from django.utils import timezone
class User(AbstractUser):
pass
class Category(models.Model):
category = models.CharField(max_length=64)
def __str__(self):
return f'{self.category}'
class AuctionListing(models.Model):
item_name = models.CharField(max_length=100)
item_image = models.ImageField(upload_to="products", null=True, blank=True)
detail = models.TextField()
price = models.IntegerField()
last_bid = models.ForeignKey('Bid', on_delete=models.CASCADE, blank=True, null=True, related_name='lst')
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='publisher_listing', null=True, blank=True)
watchers = models.ManyToManyField(User, blank=True, related_name='watched_list')
pub_date = models.DateTimeField(auto_now=True, null=True)
deadline = models.DateTimeField(null=True)
list_category = models.ForeignKey(Category, on_delete=models.CASCADE, null=True, related_name='sortion')
closed = models.BooleanField(default=False)
def __str__(self):
return f'{self.item_name} - {self.price}'
class Bid(models.Model):
bid = models.IntegerField()
user = models.ForeignKey(User, on_delete=CASCADE)
auction = models.ForeignKey(AuctionListing, on_delete=CASCADE)
bid_date = models.DateTimeField(auto_now=True)
def __str__(self):
return f'{self.bid}-{self.auction}'
class Comment(models.Model):
user = models.ForeignKey(User, on_delete=CASCADE)
com = models.TextField()
pub_date = models.DateField()
com_item = models.ForeignKey(AuctionListing, on_delete=models.CASCADE, related_name='get_comment')
def __str__(self):
return f'{self.user} - {self.pub_date}'
视图.py：
from django.contrib.auth import authenticate, login, logout
# from django.contrib.auth.decorators import login_required
from django.db import IntegrityError, reset_queries
from django.http import HttpResponse, HttpResponseRedirect
from django.shortcuts import redirect, render
from django.urls import reverse
from django.forms import ModelForm
from .models import *
def index(request):
active_list = AuctionListing.objects.all().order_by('id').reverse()
return render(request, "auctions/index.html", {'active_list': active_list })
def login_view(request):
if request.method == "POST":
# Attempt to sign user in
username = request.POST["username"]
password = request.POST["password"]
user = authenticate(request, username=username, password=password)
# Check if authentication successful
if user is not None:
login(request, user)
return HttpResponseRedirect(reverse("index"))
else:
return render(request, "auctions/login.html", {
"message": "Invalid username and/or password."
})
else:
return render(request, "auctions/login.html")
def logout_view(request):
logout(request)
return HttpResponseRedirect(reverse("index"))
def register(request):
if request.method == "POST":
username = request.POST["username"]
email = request.POST["email"]
# Ensure password matches confirmation
password = request.POST["password"]
confirmation = request.POST["confirmation"]
if password != confirmation:
return render(request, "auctions/register.html", {
"message": "Passwords must match."
})
# Attempt to create new user
try:
user = User.objects.create_user(username, email, password)
user.save()
except IntegrityError:
return render(request, "auctions/register.html", {
"message": "Username already taken."
})
login(request, user)
return HttpResponseRedirect(reverse("index"))
else:
return render(request, "auctions/register.html")
class CreateForm(ModelForm):
class Meta:
model = AuctionListing
fields = ['item_name', 'item_image', 'detail', 'price', 'deadline', 'list_category']
def create_listing(request):
user = request.user
if user.id is None:
return redirect('login')
if request.method == 'GET':
context = {
'form': CreateForm()
}
return render(request, 'auctions/create_listing.html', context)
else:
if request.method == 'POST':
form = CreateForm(request.POST or None, request.FILES or None)
if form.is_valid():
item_name = form.cleaned_data['item_name']
item_image = form.cleaned_data['item_image']
detail = form.cleaned_data['detail']
price = form.cleaned_data['price']
deadline = form.cleaned_data['deadline']
list_category = form.cleaned_data['list_category']
listing_created = AuctionListing.objects.create(
item_name = item_name,
item_image = item_image,
detail = detail,
price = price,
deadline = deadline,
list_category = list_category,
user = request.user,
)
listing_created.save()
return redirect('index')
def listing(request, pk):
user = request.user
list = AuctionListing.objects.get(id=pk)
if request.method == 'POST':
bid = request.POST.get('placebid')
user = request.user
form = Bid(bid=bid, user=user, auction=list)
form.save()
return render(request, 'auctions/listing.html', {'list': list})
index.html 是：
{% extends "auctions/layout.html" %}
{% block body %}
<h2>Active Listings</h2>
{% for each in active_list %}
<div class="back">
<div class="imag">
<img src="{{ each.item_image.url }}" alt="">
</div>
<div class="detail">
<a href="{% url 'listing' each.id %}"><h1>{{ each.item_name }}</h1></a>
<h6>Published by: <span>{{ each.user }}</span></h6>
{% if each.last_bid %}
<p>Current Bid: <span>{{ each.last_bid.bid }} </span></p>
{% else %}
<p>Current Bid: <span>{{ each.price }} </span></p>
{% endif %}
<p>Published date: <span>{{ each.pub_date }}</span></p>
<p>DeadLine: <span>{{ each.deadline }}</span></p>
<div class="bid-detail">
<p>Initial Price: {{ each.price }}</p>
<p>Watchers: 10</p>
</div>
</div>
</div>
{% endfor %}
{% endblock %}
我想在 index.html 中显示 last_bid 但我做不到。请帮我解决这个问题。我会感谢你的。