如何摆脱没有停车场的校园

Question

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

型号.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Django数据库中没有存储的搜索框中键入一个校园的名称时，它会同时显示"没有这样的校园"one_answers"没有找到停车场"。如何只为不存在的校园打印"没有这样的校园"？

Answer 1

看看下面的代码，它应该只显示不在数据库中的园区的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

您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 %}