如何摆脱没有找到这样的校园的停车场

Question

我有两个模型：校园和停车场。停车场信息的数据存储在数据库中的 json 文件中。

models.py

from django.db import models

class Campus(models.Model):
  campus_id = models.AutoField(primary_key=True)
  name = models.CharField(max_length=100)
  def __str__(self):
    return self.name

class Carpark(models.Model):
  carpark_id = models.AutoField(primary_key=True)
  name = models.CharField(max_length=100)
  spaces = models.IntegerField()
  campus_id = models.ForeignKey()
  disabled_spaces = models.IntegerField()
  def __str__(self):
    return self.name

views.py

from django.shortcuts import render
from django.http import HttpResponse
from parkatdcu.models import Campus, Carpark
import requests

def index(request):
  context = {}
  return render(request, "parkatdcu/index.html", context)

def carparks(request):
  context = {}
  Base_URL = 'http://jfoster.pythonanywhere.com/carparks/'
  campus_name = request.GET['campus']
  try:
    campus = Campus.objects.get(name__iexact=campus_name)
  except Campus.DoesNotExist:
    print('No such campus')
    return render(request,"parkatdcu/carparks.html",context)
  carparks = Carpark.objects.filter(campus_id=campus)
  carpark_info= []
  for carpark in carparks:
    URL = Base_URL + carpark.name
    r = requests.get(URL).json()
    if 'spaces_available' in r:
      spaces_available = r['spaces_available']
    else:
      spaces_available = 'not available'
    carpark_info.append({
                         'name': carpark.name,
          
           'spaces': carpark.spaces,
                         'disabled_spaces': carpark.disabled_spaces,
                         'spaces_available': spaces_available
                         }
                        )
context['campus'] = campus_name
context['carparks'] = carpark_info
return render(request,"parkatdcu/carparks.html",context)

carparks.html

{% if campus %}
<h2>{{ campus }}</h2>
{% else %}
<h2>No such campus</h2>
{% endif %}
{% if carparks %}
<ul>
{% for carpark in carparks %}
<li>{{carpark.name}}: {{carpark.spaces}} spaces, {{carpark.disabled_spaces}} spaces for people with 
disabilities
<br>Spaces available:  {{ carpark.spaces_available }}<br><br>
</li>
{% endfor %}
{% else%}
<p>No carparks found</p>
{% endif %}
</ul>

当我在搜索框中输入未存储在 Django 数据库中的校园名称时，它会同时显示“没有这样的校园”和“找不到停车场”。如何只为不存在的校区打印“没有这样的校区”？

Answer 1

看看下面的代码，它应该只为不在数据库中的校园显示No such campus 消息。

<h2>{% if campus %} {{ campus }} {% else %} No such campus {% endif %}</h2>



{% if campus %} {# HERE -- i just wrapped the block with if statement #}



  {% if carparks %}
    <ul>
      {% for carpark in carparks %}
      <li>{{carpark.name}}: {{carpark.spaces}} spaces, {{carpark.disabled_spaces}} spaces for people with disabilities<br>Spaces available:  {{ carpark.spaces_available }}<br><br></li>
      {% endfor %}
    </ul>
  {% else%}
    <p>No carparks found</p>
  {% endif %}



{% endif %}

Answer 2

你应该只需要删除上面的行

{% if campus %}
    <h2>{{ campus }}</h2>
{% else %}
    <h2>No such campus</h2>
{% endif %}

{% if carparks %}
    <ul>

    {% for carpark in carparks %}
        <li>{{carpark.name}}: {{carpark.spaces}} spaces, {{carpark.disabled_spaces}} spaces for people with 
disabilities
        <br>Spaces available:  {{ carpark.spaces_available }}<br><br>
        </li>
    {% endfor %}

{% else%}                    <--- REMOVE THIS LINE 
    <p>No carparks found</p> <--- REMOVE THIS LINE
    
    </ul>                    <--- MOVE THIS LINE INSIDE {% endif %}
{% endif %}