No User匹配给定的查询

Question

在尝试在博客应用程序中显示后细节模板时，我得到一个错误No User matches a given query。在我的模型中，我继承了用户模型。有什么问题吗?

# Third party imports.
from django.contrib.auth.models import User
from django.db import models
from django.urls import reverse
from django.utils import timezone
class Post(models.Model):
"""
Creates Model for a post in the database.
"""
title = models.CharField(max_length=100)
sub_title = models.CharField(max_length=100)
content = models.TextField()
date_posted = models.DateTimeField(default=timezone.now)
author = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
"""
A string representation of the post model.
"""
return self.title
def get_absolute_url(self):
"""
Creates the absolute url for a particular post.
"""
return reverse('blog:post-detail', kwargs={'pk': self.pk})

views.py

class PostDetailView(DetailView):
"""
View for a post's details
"""
model = Post
template_name ='blog/post_detail.html'
context_object_name = 'posts'
paginate_by = 3

def get_queryset(self):
user = get_object_or_404(User, username=self.kwargs.get('username'))
return Post.objects.filter(author=user).order_by('-date_posted')

urls . py:

# Third party imports.
from django.urls import path
from .views import (
PostListView,
PostDetailView,
PostCreateView,
PostUpdateView,
PostDeleteView,
UserPostListView,
)
# Local application imports.
from . import views
# Specifies the app's name.
app_name = "blog"
urlpatterns = [
path('', PostListView.as_view(), name='home'),  # url for post list.
path('user/<str:username>/',
UserPostListView.as_view(),
name='user-posts'),  # url for specific user post.
path('post/<int:pk>/',
PostDetailView.as_view(),
name='post-detail'),  # url for post detail.
path('post/new/',
PostCreateView.as_view(),
name='post-create'),  # url to create new post.
path('post/<int:pk>/update/',
PostUpdateView.as_view(),
name='post-update'),  # url to update post.
path('post/<int:pk>/delete/',
PostDeleteView.as_view(), name='post-delete'),  # url to delete post.
path('about/', views.about, name='about'),  # url for about page.
]

home。

{% extends 'blog/base.html' %}
{% load static %}
{% block crumb %}
{% for post in posts %}
<div class="post-preview">
<a href="{% url 'blog:post-detail' post.id %}">
<h2 class="post-title">{{ post.title }}   </h2>
<h3 class="post-subtitle">{{ post.sub_title }}  </h3>
</a>
<p class="post-meta" style="font-weight: 300;"> Posted by 
<a class="text-muted">{{post.author}} on {{ post.date_posted|date:"F d, Y" }}</a>

</p>
</div>
<hr class="my-4" />
{% endfor %}
{% endblock %}

post_detail.html

{% extends "blog/base.html" %}
{% block content %}
<article class="media content-section">
<img class="rounded-circle article-img"
src="{{ object.author.profile.image.url }}">
<div class="media-body">
<div class="article-metadata">
<a class="mr-2"
href="{% url 'blog:user-posts' object.author.username %}">{{ object.author }}
</a>
<small class="text-muted">{{ object.date_posted|date:"F d, Y" }}</small>
{% if object.author == user %}
<div>
<a class="btn btn-secondary btn-sm mt-1 mb-1"
href="{% url 'blog:post-update' object.id %}">Update
</a>
<a class="btn btn-danger btn-sm mt-1 mb-1"
href="{% url 'blog:post-delete' object.id %}">Delete
</a>
</div>
{% endif %}
</div>
<h2 class="article-title">{{ object.title }}</h2>
<p class="article-content">{{ object.content }}</p>
</div>
</article>
{% endblock content %}

Answer 1

一些与你得到的错误没有直接关系的错误注释

• 你正在使用一个DetailView(它显示了单个对象的详细信息)，它看起来像你想要一个ListView(列出用户的帖子)。
  • 您的context_object_name是复数形式，这意味着您确实需要一个列表。
  • paginate_by在DetailViews中没有效果，因为单对象视图无法分页。
• 你的视图是指一个blog/post_detail.html，而你已经粘贴在一个home.html。是哪一个?
• 您说"在我的模型中，我继承了用户模型"，但看起来您没有导入自定义用户模型，而是默认的from django.contrib.auth.models import User。如果你真的使用继承自BaseUser(不是user)的自定义用户模型，那么这也是错误的。

---

错误本身，我想(因为您没有向我们提供回溯)来自

user = get_object_or_404(User, username=self.kwargs.get('username'))

这意味着您没有在该视图的URL中传递<username>，或者您使用的<username>是不正确的(并且没有这样的用户)。(你没有给我们看你的urls.py，所以这只是一个猜测。)

(在任何情况下，Detail视图的URL都可能不是指向用户名，而是指向帖子的唯一标识符)

---

编辑

在原始帖子的编辑之后，问题是get_queryset()在DetailView中是无关的(因为不需要按用户名过滤)，因此该类可以简化为:

class PostDetailView(DetailView):
model = Post
template_name ='blog/post_detail.html'