NoReverseMatch at / 模板渲染时出错
NoReverseMatch at / Error during template rendering
当我打开 http://127.0.0.1:8000/
即 home.html
时,我得到:
NoReverseMatch at / and Reverse for 'exam-detail' with arguments '('',)' not found. 1 pattern(s) tried: ['exam/(?P[^/]+)$']
我认为错误是由于 <str:pk>
in urls.py
.
urls.py文件如下:
from . import views
from .views import ExamListView, ExamDetailView
app_name='map'
urlpatterns = [
path("", ExamListView.as_view(), name='map-home'),
path("exam/<str:pk>", ExamDetailView.as_view(), name="exam-detail"),
path("login_student/", views.login_student, name='map-login'),
path("register_student", views.register_student, name='map-register'),
path('add_student/', views.add_student, name='add_student'),
path('front/', views.front, name="front"),
]
models.py:
subject = models.TextField(primary_key = True, unique = True)
def __str__(self):
return self.subject
home.html
{% extends "map/base.html" %}
{% block content %}
<p>WELCOME HOME</p>
{% for exam in exams %}
<article class="media content-section">
<div class="media-body">
<div class="article-metadata">
<a class="mr-2" href="{% url 'map:exam-detail' exam.subject %}">{{ exam }} </a>
</div>
</div>
</article>
{% endfor %}
{% endblock content %}
base.html
{% load static %}
<!DOCTYPE html>
<html>
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="{% static 'map/main.css' %}">
{% if title %}
<title>{{ title }}</title>
{% else %}
<title> MAP PAGE </title>
{% endif %}
</head>
<body>
<header class="site-header">
<nav class="navbar navbar-expand-md navbar-dark bg-steel fixed-top">
<div class="container">
<a class="navbar-brand mr-4" href="/">Project M.A.P</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarToggle" aria-controls="navbarToggle" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarToggle">
<div class="navbar-nav mr-auto">
<a class="nav-item nav-link" href="{% url 'map:map-home' %}">Home</a> <!-- no hardcoded links -->
<a class="nav-item nav-link" href="{% url 'map:map-home' %}">About</a>
</div>
<!-- Navbar Right Side -->
<div class="navbar-nav">
{% if user.is_authenticated %}
<a class="nav-item nav-link" href="{% url 'profile' %}">Profile</a>
<a class="nav-item nav-link" href="{% url 'logout' %}">Logout</a>
{% else %}
<a class="nav-item nav-link" href="{% url 'login' %}">Login</a>
<a class="nav-item nav-link" href="{% url 'register' %}">Register</a>
<a class="nav-item nav-link" href="{% url 'map:map-register' %}">Student</a>
{% endif %}
</div>
</div>
</div>
</nav>
</header>
<main role="main" class="container">
<div class="row">
<div class="col-md-8">
{% if messages %}
{% for message in messages %}
<div class="alert alert-{{ message.tags }}">
{{ message }}
</div>
{% endfor %}
{% endif %}
{% block content %}{% endblock %}
</div>
<div class="col-md-4">
<div class="content-section">
<h3>Our Sidebar</h3>
<p class='text-muted'>You can put any information here you'd like.
<ul class="list-group">
<li class="list-group-item list-group-item-light">Latest Posts</li>
<li class="list-group-item list-group-item-light">Announcements</li>
<li class="list-group-item list-group-item-light">Calendars</li>
<li class="list-group-item list-group-item-light">etc</li>
</ul>
</p>
</div>
</div>
</div>
</main>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>[enter image description here][1]
views.py
from django.shortcuts import render
from django.http import HttpResponse
from django.http import HttpResponseRedirect
from django.urls import reverse
from . models import Student, Exam
from django.views.generic import ListView, DetailView
def home(request):
context = {
'exams': Exam.objects.all()
}
return render(request, 'map/home.html', context)
class ExamListView(ListView): #class based views
model = Exam
template_name = 'map/home.html' #<app>/<model>_<viewtype>.html
context_object_name = 'exams'
ordering = ['subject'] #['-exam']
class ExamDetailView(DetailView):
model = Exam
您在 home.html 中错过了 exam.pk
以这种方式更新您的代码,
<div class="article-metadata">
<a class="mr-2" href="{% url 'map:exam-detail'
exam.pk %}">{{ exam }} </a>
</div>
</div>
在
python manage.py shell
from my_app_name.models import Exam
exam = Exam()
exam.subject = ""
exam.save()
我已经执行了这些行。我还为 "google"、"english"、..
等科目创建了考试
现在Exam.objects.all()
returns
<QuerySet [<Exam: google>, <Exam: english>, <Exam: >]>
问题是由于有一个长度为零的字符串作为其中一个考试对象的主题。现在我使用 Exam.objects.get(subject="").delete()
删除了那个考试。问题已解决。
{% url 'map:exam-detail' exam.subject %}
或
{% url 'map:exam-detail' exam %}
或
{% url 'map:exam-detail' exam.pk %}
所有这些现在都在工作,因为所有这些都在返回主题。但是{% url 'map:exam-detail' exam.id %}
不行。因为我在Exam model中将subject设为primary_key,所以Exam model don '没有属性 id(当没有提到 primary_key 时默认添加)。
思考为什么它接受了空字符串作为主题,尽管我将其定义为primary_key。
然后我想阅读有关 django.db.models.TextField 的内容,然后键入帮助 (TextField) 并获得
TextField(verbose_name=None, name=None, primary_key=False, max_length=None, unique=False, blank=False, null=False, db_index=False, rel=None, default=<class 'django.db.models.fields.NOT_PROVIDED'>, editable=True, serialize=True, unique_for_date=None, unique_for_month=None, unique_for_year=None, choices=None, help_text='', db_column=None, db_tablespace=None, auto_created=False, validators=(), error_messages=None)
现在尝试了验证器...
后续问题
谢谢大家
莫妮卡
当我打开 http://127.0.0.1:8000/
即 home.html
时,我得到:
NoReverseMatch at / and Reverse for 'exam-detail' with arguments '('',)' not found. 1 pattern(s) tried: ['exam/(?P[^/]+)$']
我认为错误是由于 <str:pk>
in urls.py
.
urls.py文件如下:
from . import views
from .views import ExamListView, ExamDetailView
app_name='map'
urlpatterns = [
path("", ExamListView.as_view(), name='map-home'),
path("exam/<str:pk>", ExamDetailView.as_view(), name="exam-detail"),
path("login_student/", views.login_student, name='map-login'),
path("register_student", views.register_student, name='map-register'),
path('add_student/', views.add_student, name='add_student'),
path('front/', views.front, name="front"),
]
models.py:
subject = models.TextField(primary_key = True, unique = True)
def __str__(self):
return self.subject
home.html
{% extends "map/base.html" %}
{% block content %}
<p>WELCOME HOME</p>
{% for exam in exams %}
<article class="media content-section">
<div class="media-body">
<div class="article-metadata">
<a class="mr-2" href="{% url 'map:exam-detail' exam.subject %}">{{ exam }} </a>
</div>
</div>
</article>
{% endfor %}
{% endblock content %}
base.html
{% load static %}
<!DOCTYPE html>
<html>
<head>
<!-- Required meta tags -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<!-- Bootstrap CSS -->
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<link rel="stylesheet" type="text/css" href="{% static 'map/main.css' %}">
{% if title %}
<title>{{ title }}</title>
{% else %}
<title> MAP PAGE </title>
{% endif %}
</head>
<body>
<header class="site-header">
<nav class="navbar navbar-expand-md navbar-dark bg-steel fixed-top">
<div class="container">
<a class="navbar-brand mr-4" href="/">Project M.A.P</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarToggle" aria-controls="navbarToggle" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarToggle">
<div class="navbar-nav mr-auto">
<a class="nav-item nav-link" href="{% url 'map:map-home' %}">Home</a> <!-- no hardcoded links -->
<a class="nav-item nav-link" href="{% url 'map:map-home' %}">About</a>
</div>
<!-- Navbar Right Side -->
<div class="navbar-nav">
{% if user.is_authenticated %}
<a class="nav-item nav-link" href="{% url 'profile' %}">Profile</a>
<a class="nav-item nav-link" href="{% url 'logout' %}">Logout</a>
{% else %}
<a class="nav-item nav-link" href="{% url 'login' %}">Login</a>
<a class="nav-item nav-link" href="{% url 'register' %}">Register</a>
<a class="nav-item nav-link" href="{% url 'map:map-register' %}">Student</a>
{% endif %}
</div>
</div>
</div>
</nav>
</header>
<main role="main" class="container">
<div class="row">
<div class="col-md-8">
{% if messages %}
{% for message in messages %}
<div class="alert alert-{{ message.tags }}">
{{ message }}
</div>
{% endfor %}
{% endif %}
{% block content %}{% endblock %}
</div>
<div class="col-md-4">
<div class="content-section">
<h3>Our Sidebar</h3>
<p class='text-muted'>You can put any information here you'd like.
<ul class="list-group">
<li class="list-group-item list-group-item-light">Latest Posts</li>
<li class="list-group-item list-group-item-light">Announcements</li>
<li class="list-group-item list-group-item-light">Calendars</li>
<li class="list-group-item list-group-item-light">etc</li>
</ul>
</p>
</div>
</div>
</div>
</main>
<!-- Optional JavaScript -->
<!-- jQuery first, then Popper.js, then Bootstrap JS -->
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>[enter image description here][1]
views.py
from django.shortcuts import render
from django.http import HttpResponse
from django.http import HttpResponseRedirect
from django.urls import reverse
from . models import Student, Exam
from django.views.generic import ListView, DetailView
def home(request):
context = {
'exams': Exam.objects.all()
}
return render(request, 'map/home.html', context)
class ExamListView(ListView): #class based views
model = Exam
template_name = 'map/home.html' #<app>/<model>_<viewtype>.html
context_object_name = 'exams'
ordering = ['subject'] #['-exam']
class ExamDetailView(DetailView):
model = Exam
您在 home.html 中错过了 exam.pk 以这种方式更新您的代码,
<div class="article-metadata">
<a class="mr-2" href="{% url 'map:exam-detail'
exam.pk %}">{{ exam }} </a>
</div>
</div>
在 python manage.py shell
from my_app_name.models import Exam
exam = Exam()
exam.subject = ""
exam.save()
我已经执行了这些行。我还为 "google"、"english"、..
等科目创建了考试现在Exam.objects.all()
returns
<QuerySet [<Exam: google>, <Exam: english>, <Exam: >]>
问题是由于有一个长度为零的字符串作为其中一个考试对象的主题。现在我使用 Exam.objects.get(subject="").delete()
删除了那个考试。问题已解决。
{% url 'map:exam-detail' exam.subject %}
或
{% url 'map:exam-detail' exam %}
或
{% url 'map:exam-detail' exam.pk %}
所有这些现在都在工作,因为所有这些都在返回主题。但是{% url 'map:exam-detail' exam.id %}
不行。因为我在Exam model中将subject设为primary_key,所以Exam model don '没有属性 id(当没有提到 primary_key 时默认添加)。
思考为什么它接受了空字符串作为主题,尽管我将其定义为primary_key。 然后我想阅读有关 django.db.models.TextField 的内容,然后键入帮助 (TextField) 并获得
TextField(verbose_name=None, name=None, primary_key=False, max_length=None, unique=False, blank=False, null=False, db_index=False, rel=None, default=<class 'django.db.models.fields.NOT_PROVIDED'>, editable=True, serialize=True, unique_for_date=None, unique_for_month=None, unique_for_year=None, choices=None, help_text='', db_column=None, db_tablespace=None, auto_created=False, validators=(), error_messages=None)
现在尝试了验证器...
后续问题
谢谢大家 莫妮卡