如何将过滤后的对象变量从 views.py 传递到 HTML 模板答案

【问题标题】：How to pass a filtered object variable from views.py to a HTML template如何将过滤后的对象变量从 views.py 传递到 HTML 模板
【发布时间】：2020-04-23 00:01:11
【问题描述】：

当前路径：

ticket-strap/
     ticketstrap/
           templates/
                 home.html (home.html file in question)
                 index.html
     tickets/
          __pycache__
          migrations
          templates/
               __init__.py
               admin.py
               apps.py
               models.py (models file in question)
               tests.py
               urls.py (urls file in question)
               views.py (views file in question)
     ticketstrap/
          __pycache__
          __init__.py
          asgi.py
          settings.py
          urls.py (urls file in question)
          views.py
          wsgi.py

代码如下：

urls.py（来自票务应用）

from django.contrib import admin
from django.conf.urls import url
from django.conf.urls import include
from django.urls import path
from . import views

app_name = 'ticketstrap'

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', views.home, name="homepage"),
    path('home/', views.home, name="home"),
    path('tickets/', include('tickets.urls')),
    path('accounts/', include('accounts.urls'))
    # url(r'^$', views.home, name="homepage"),
    # url(r'^home/', views.home, name="home"),
    # url(r'^tickets/', include('tickets.urls')),
    # url(r'^accounts/', include('accounts.urls'))
]

urls.py（来自门票应用程序）

from django.conf.urls import url
from django.urls import path
from . import views

app_name = 'tickets'

urlpatterns = [
    path('', views.tickets, name="tickets"),
    path('new_ticket_submission/', views.new_ticket_submission, name="new_ticket_submission"),
    path('<int:ticket_id>/', views.ticket_details, name="ticket_details")
    # url(r'^$', views.tickets, name="tickets"),
    # url(r'^new_ticket_submission/$', views.new_ticket_submission, name="new_ticket_submission")
]

models.py（来自门票应用）

from django.db import models

class Ticket(models.Model):
    customer_name = models.CharField(max_length=50)
    customer_email = models.CharField(max_length=100)
    ticket_subject = models.CharField(max_length=200)
    ticket_type = models.CharField(max_length=20)
    ticket_status = models.CharField(max_length=30)
    ticket_priority = models.CharField(max_length=30)
    ticket_description = models.TextField()
    ticket_tags = models.CharField(max_length=50)
    # slug = models.SlugField()
    # submit_date = models.DateTimeField(auto_now_add=True)
    # submit_date = models.DateTimeField('Date Submitted')

    def __str__(self):
        return "status: {} | Subject: {} | Name: {}".format(self.ticket_status, self.ticket_subject, self.customer_name)

views.py（来自门票应用程序）

from django.http import HttpResponse
from django.shortcuts import render
from django.contrib.auth.decorators import login_required
from tickets.models import Ticket

@login_required(login_url="/accounts/login")
def home(request):
    return render(request, "home.html")

def ticket_status_count(request):
    open_count = Ticket.objects.filter(ticket_status='open').count()
    in_progress_count = Ticket.objects.filter(ticket_status='inProgress').count()
    pending_count = Ticket.objects.filter(ticket_status='pending').count()
    resolved_count = Ticket.objects.filter(ticket_status='resolved').count()
    closed_count = Ticket.objects.filter(ticket_status='closed').count()
    waiting_on_customer_count = Ticket.objects.filter(ticket_status='waitingOnCustomer').count()
    waiting_on_third_party_count = Ticket.objects.filter(ticket_status='waitingOnThirdParty').count()
    return render(request, 'home.html', {'open_count': open_count})

home.html

{% extends "index.html" %}

{% block content %}
  <!-- Today's Tasks Header -->
  <header id="header">
    <div class="container">
      <div class="row">
        <div class="col-md-6">
          <h2><svg class="bi bi-calendar" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
            <path fill-rule="evenodd" d="M16 2H4a2 2 0 00-2 2v12a2 2 0 002 2h12a2 2 0 002-2V4a2 2 0 00-2-2zM3 5.857C3 5.384 3.448 5 4 5h12c.552 0 1 .384 1 .857v10.286c0 .473-.448.857-1 .857H4c-.552 0-1-.384-1-.857V5.857z" clip-rule="evenodd"/>
            <path fill-rule="evenodd" d="M8.5 9a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm-9 3a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm-9 3a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2zm3 0a1 1 0 100-2 1 1 0 000 2z" clip-rule="evenodd"/>
          </svg><small> Today's Tasks</small></h2>
        </div>
      </div>
    </header>

    <section id="breadcrumb">
      <div class="container-fluid">
        <ol class="breadcrumb">
          <li class="active">Dashboard</li>
        </ol>
      </div>
    </section>

    <section id="main">
      <div class="container">
        <div class="row">

          <!-- Left Dashboard -->
          <div class="col-md-3">
            <div class="list-group">
              <a href="/index/" class="list-group-item list-group-item-action active main-color-bg"><svg class="bi bi-display-fill" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path d="M7.75 15.5c.167-.333.25-.833.25-1.5h4c0 .667.083 1.167.25 1.5H13a.5.5 0 010 1H7a.5.5 0 010-1h.75z"/>
                <path fill-rule="evenodd" d="M15.991 5H4c-.325 0-.502.078-.602.145a.758.758 0 00-.254.302A1.46 1.46 0 003 6.01V12c0 .325.078.502.145.602.07.105.17.188.302.254a1.464 1.464 0 00.538.143L4.01 13H16c.325 0 .502-.078.602-.145a.758.758 0 00.254-.302 1.464 1.464 0 00.143-.538L17 11.99V6c0-.325-.078-.502-.145-.602a.757.757 0 00-.302-.254A1.46 1.46 0 0015.99 5zM16 4H4C2 4 2 6 2 6v6c0 2 2 2 2 2h12c2 0 2-2 2-2V6c0-2-2-2-2-2z" clip-rule="evenodd"/>
                <path d="M4 6h12v6H4z"/>
              </svg> Dashboard</a>
              <a href="/tickets/" class="list-group-item list-group-item-action"><svg class="bi bi-tag-fill" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path fill-rule="evenodd" d="M4 3a1 1 0 00-1 1v4.586a1 1 0 00.293.707l7 7a1 1 0 001.414 0l4.586-4.586a1 1 0 000-1.414l-7-7A1 1 0 008.586 3H4zm4 3.5a1.5 1.5 0 11-3 0 1.5 1.5 0 013 0z" clip-rule="evenodd"/>
              </svg> Tickets  <span class="badge badge-pill badge-primary">change_num</span></a>
              <a href="/contacts/" class="list-group-item list-group-item-action"><svg class="bi bi-person-fill" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path fill-rule="evenodd" d="M5 16s-1 0-1-1 1-4 6-4 6 3 6 4-1 1-1 1H5zm5-6a3 3 0 100-6 3 3 0 000 6z" clip-rule="evenodd"/>
              </svg> Contacts</a>
              <a href="/companies/" class="list-group-item list-group-item-action"><svg class="bi bi-building" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path fill-rule="evenodd" d="M17.285 2.089a.5.5 0 01.215.411v15a.5.5 0 01-.5.5h-3a.5.5 0 01-.5-.5V16h-1v1.5a.5.5 0 01-.5.5H3a.5.5 0 01-.5-.5v-6a.5.5 0 01.418-.493l5.582-.93V5.5a.5.5 0 01.324-.468l8-3a.5.5 0 01.46.057zM9.5 5.846V10.5a.5.5 0 01-.418.493l-5.582.93V17h8v-1.5a.5.5 0 01.5-.5h2a.5.5 0 01.5.5V17h2V3.221l-7 2.625z" clip-rule="evenodd"/>
                <path fill-rule="evenodd" d="M8.5 17.5v-7h1v7h-1z" clip-rule="evenodd"/>
                <path d="M4.5 13h1v1h-1v-1zm2 0h1v1h-1v-1zm-2 2h1v1h-1v-1zm2 0h1v1h-1v-1zm6-10h1v1h-1V5zm2 0h1v1h-1V5zm-4 2h1v1h-1V7zm2 0h1v1h-1V7zm2 0h1v1h-1V7zm-2 2h1v1h-1V9zm2 0h1v1h-1V9zm-4 0h1v1h-1V9zm0 2h1v1h-1v-1zm2 0h1v1h-1v-1zm2 0h1v1h-1v-1zm-4 2h1v1h-1v-1zm2 0h1v1h-1v-1zm2 0h1v1h-1v-1z"/>
              </svg> Companies</a>
              <a href="/reports/" class="list-group-item list-group-item-action"><svg class="bi bi-graph-up" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path d="M2 2h1v16H2V2zm1 15h15v1H3v-1z"/>
                <path fill-rule="evenodd" d="M16.39 6.312l-4.349 5.437L9 8.707l-3.646 3.647-.708-.708L9 7.293l2.959 2.958 3.65-4.563.781.624z" clip-rule="evenodd"/>
                <path fill-rule="evenodd" d="M12 5.5a.5.5 0 01.5-.5h4a.5.5 0 01.5.5v4a.5.5 0 01-1 0V6h-3.5a.5.5 0 01-.5-.5z" clip-rule="evenodd"/>
              </svg> Reports</a>
              <a href="/adminSettings/" class="list-group-item list-group-item-action"><svg class="bi bi-gear-fill" width="1em" height="1em" viewBox="0 0 20 20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
                <path fill-rule="evenodd" d="M11.405 3.05c-.413-1.4-2.397-1.4-2.81 0l-.1.34a1.464 1.464 0 01-2.105.872l-.31-.17c-1.283-.698-2.686.705-1.987 1.987l.169.311c.446.82.023 1.841-.872 2.105l-.34.1c-1.4.413-1.4 2.397 0 2.81l.34.1a1.464 1.464 0 01.872 2.105l-.17.31c-.698 1.283.705 2.686 1.987 1.987l.311-.169a1.464 1.464 0 012.105.872l.1.34c.413 1.4 2.397 1.4 2.81 0l.1-.34a1.464 1.464 0 012.105-.872l.31.17c1.283.698 2.686-.705 1.987-1.987l-.169-.311a1.464 1.464 0 01.872-2.105l.34-.1c1.4-.413 1.4-2.397 0-2.81l-.34-.1a1.464 1.464 0 01-.872-2.105l.17-.31c.698-1.283-.705-2.686-1.987-1.987l-.311.169a1.464 1.464 0 01-2.105-.872l-.1-.34zM10 12.93a2.929 2.929 0 100-5.858 2.929 2.929 0 000 5.858z" clip-rule="evenodd"/>
              </svg> Admin</a>
            </div>
          </div>

          <!-- Unresolved, Due Today, and Open Cards -->
          <div class="col-md-9">
            <div class="card-deck">
              <div class="card">
                <div class="card-body">
                  <h3 class="card-title">Open</h3>
                  <h1 class="card-text">
                    {{open_count}}
                  </h1>
                  <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
                </div>
              </div>
              <div class="card">
                <div class="card-body">
                  <h3 class="card-title">On Hold</h3>
                  <h1 class="card-text">12</h1>
                  <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
                </div>
              </div>
              <div class="card">
                <div class="card-body">
                  <h3 class="card-title">Unresolved</h3>
                  <h1 class="card-text">42</h1>
                  <p class="card-text"><small class="text-muted">Last updated 3 mins ago</small></p>
                </div>
              </div>
            </div>
        </div>


        </div> <!-- Row collapse -->
        <!-- <div class="col-md-9">

        </div> -->
      </div>
    </section>
{% endblock %}

在 views.py 中，ticket_status_count 计算我的票证管理系统中的每个票证实例。在这种情况下，我想计算有多少票被标记为“打开”，分配给变量open_count。然后我尝试从views.py 中获取open_count 并将其显示在home.html 上。在我的 Django 数据库中，我已经确认有 2 张票标记为“打开”，Ticket.objects.filter(ticket_status='open').count() 确实返回了正确的数字，这是通过 Python Shell 中的测试确定的。但是，我的浏览器中的 home.html 中没有显示数字 2。

到目前为止我已经尝试过：

在views.py中我只试过return open_count。

在 home.html 我试过了：

{% for status in open_count %}
 {{status}}
{ % endfor %}

和

{% if open_count %}
 {{open_status}}
{% endif %}

【问题讨论】：

上下文变量名为“open_count”，但您使用的是“open_status”
你能分享这两个视图的urls.py 吗？
在初始代码中，正确的是，模板中间的{{open_count}} - 这应该可以工作。但在后面的示例中使用了open_status，这一事实让人怀疑视图和模板的正确版本是否曾经一起使用过。
@IainShelvington 我很抱歉，那些本来是 open_count。我正在重新输入代码，并且一定把我的变量搞混了。我会立即编辑帖子
@BrianLee 你能分享这两个视图的urls.py 以及你当前的路径吗？

标签： python django django-models django-templates django-views

【解决方案1】：

将计数添加到您的主页上下文

@login_required(login_url="/accounts/login")
def home(request):
    return render(request, "home.html", {
        'open_count': Ticket.objects.filter(ticket_status='open').count()
    })

要添加您想要的所有计数，您可以将它们单独添加到上下文中

@login_required(login_url="/accounts/login")
def home(request):
    return render(request, "home.html", {
        'open_count': Ticket.objects.filter(ticket_status='open').count(),
'in_progress_count': Ticket.objects.filter(ticket_status='inProgress').count(),
'pending_count': Ticket.objects.filter(ticket_status='pending').count(),
'resolved_count': Ticket.objects.filter(ticket_status='resolved').count(),
'closed_count': Ticket.objects.filter(ticket_status='closed').count(),
'waiting_on_customer_count': Ticket.objects.filter(ticket_status='waitingOnCustomer').count(),
'waiting_on_third_party_count': Ticket.objects.filter(ticket_status='waitingOnThirdParty').count()
    })

要在单个查询中返回许多不同计数的结果，您可以使用 aggregation，这将在 1 个 DB 调用中返回包含所有值的字典

@login_required(login_url="/accounts/login")
def home(request):
    return render(request, "home.html", Ticket.objects.aggregate(
        open_count=Count('id', filter=Q(ticket_status='open')),
        in_progress_count=Count('id', filter=Q(ticket_status='inProgress')),
        pending_count=Count('id', filter=Q(ticket_status='pending')),
        resolved_count=Count('id', filter=Q(ticket_status='resolved')),
        closed_count=Count('id', filter=Q(ticket_status='open')),
        waiting_on_customer_count=Count('id', filter=Q(ticket_status='waitingOnCustomer')),
        waiting_on_third_party_count=Count('id', filter=Q(ticket_status='waitingOnThirdParty')),
    ))

【讨论】：

你是圣人——它成功了！有没有办法，怎么说呢，多次退货？例如，在home.html 中，我有一个地方可以显示打开的、未解决的和暂停的票证的数量，这些票证都是从models.py 获得的，具有与Ticket.objects.filter(ticket_status='open').count() 类似的功能，我想拥有它们都从home(request)返回
@BrianLee 您可以将它们全部单独传递给上下文（传递给render 的字典），但有更好的方法。 1分钟，我会更新答案
@BrianLee 您使用的是哪个版本的 Django 以及哪个数据库？
我使用的是 django 版本 3.0.1 - 不太清楚你所说的“哪个数据库”是什么意思
我的意思是 MySQL 或 PostgreSQL。用如何将所有这些计数添加到视图中更新了答案