Python 无法将关键字“pub_u2;”解析为views.py中的字段

在下面的教程中，

我的操作与教程中的指导完全相同，在polls/templates/polls/index.html中创建模板文件：

polls/templates/polls/index.html¶
{% if latest_question_list %}
    <ul>
    {% for question in latest_question_list %}
        <li><a href="/polls/{{ question.id }}/">{{ question.question_text }}</a></li>
    {% endfor %}
    </ul>
{% else %}
    <p>No polls are available.</p>
{% endif %}

当我启动服务器并访问URL:时，出现以下错误：

FieldError at /polls/
Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
Request Method: GET
Request URL:    http://127.0.0.1:8000/polls/
Django Version: 2.1.7
Exception Type: FieldError
Exception Value:    
Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
Exception Location: /home/martin/anaconda3/envs/web/lib/python3.7/site-packages/django/db/models/sql/query.py in names_to_path, line 1389
Python Executable:  /home/martin/anaconda3/envs/web/bin/python
Python Version: 3.7.2
Python Path:    
['/home/martin/nlp/web/web',
 '/home/martin/anaconda3/envs/web/lib/python37.zip',
 '/home/martin/anaconda3/envs/web/lib/python3.7',
 '/home/martin/anaconda3/envs/web/lib/python3.7/lib-dynload',
 '/home/martin/anaconda3/envs/web/lib/python3.7/site-packages']
Server time:    Sun, 3 Mar 2019 09:20:08 +0000
Error during template rendering
In template /home/martin/nlp/web/web/polls/templates/polls/index.html, error at line 1

Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
1   {% if latest_question_list %}
2       <ul>
3       {% for question in latest_question_list %}
4           <li><a href="/polls/{{ question.id }}/">{{ question.question_text }}</a></li>
5       {% endfor %}
6       </ul>
7   {% else %}
8       <p>No polls are available.</p>
9   {% endif %}
10  

---

我在应用程序的终端运行这一行，没有发现任何问题。但是，当我在服务器上运行应用程序时，我总是遇到这样一个恼人的问题。

您的代码中是否有打字错误：

我猜你是这样写的：

问题.对象.按'-pub_date'[：5]排序

这意味着所有问题都按名为“pub_u”的字段降序排列，因为“-pub_udate”[：5]是“-pub_u”

您要编写以下代码：

问题.对象.按'-pub_date'[：5]排序

---

这意味着最新的五个问题。

也许你是按“-pub_date”[：5]写订单，而不是按“-pub_date”[：5]写订单？有什么区别？正是sameLook仔细的。括号后或字符串后的括号：pub_date'[vs pub_date'[。完全正确！谢谢，我将其作为解决方案发布。

FieldError at /polls/
Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
Request Method: GET
Request URL:    http://127.0.0.1:8000/polls/
Django Version: 2.1.7
Exception Type: FieldError
Exception Value:    
Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
Exception Location: /home/martin/anaconda3/envs/web/lib/python3.7/site-packages/django/db/models/sql/query.py in names_to_path, line 1389
Python Executable:  /home/martin/anaconda3/envs/web/bin/python
Python Version: 3.7.2
Python Path:    
['/home/martin/nlp/web/web',
 '/home/martin/anaconda3/envs/web/lib/python37.zip',
 '/home/martin/anaconda3/envs/web/lib/python3.7',
 '/home/martin/anaconda3/envs/web/lib/python3.7/lib-dynload',
 '/home/martin/anaconda3/envs/web/lib/python3.7/site-packages']
Server time:    Sun, 3 Mar 2019 09:20:08 +0000
Error during template rendering
In template /home/martin/nlp/web/web/polls/templates/polls/index.html, error at line 1

Cannot resolve keyword 'pub_' into field. Choices are: choice, id, pub_date, question_text
1   {% if latest_question_list %}
2       <ul>
3       {% for question in latest_question_list %}
4           <li><a href="/polls/{{ question.id }}/">{{ question.question_text }}</a></li>
5       {% endfor %}
6       </ul>
7   {% else %}
8       <p>No polls are available.</p>
9   {% endif %}
10  

latest_question_list = Question.objects.order_by('-pub_date')[:5]