Question

我是Django的新手，到目前为止，我已经掌握了基础知识，但我正在努力做一些我从天堂学到的教程并没有教会我的东西，基本上我想要做的是，我在models.py中有一个名为delegates_num的字段，该字段是注册特定课程的代表人数的计数器。每当有人报名参加特定课程时，我希望能够将该字段增加1，课程为[ITIL, Change Management, Management of Risk, Programme Management, PRINCE2]

因此，例如，如果用户预订了ITIL课程，该课程的计数器将增加1.每个课程的空间限制为15个，所以某个地方的条件如下：

    if course.name = 'ITIL' && if delegates_num > 15
    redirect user to 'course is full page'
 else submit registration form and increment delegates_num by 1

对于任何帮助我都非常感激，到目前为止这里是代码：

class Course(models.Model):
    MY_CHOICES = (
        ('Open', 'Open'),
        ('Closed', 'Closed'),
        ('Fully Booked', 'Fully Booked'),
    )
    course_name = models.CharField(max_length=40)
    course_code = models.CharField(max_length=40)
    price = models.CharField(max_length=40, default='add price')
    topic_details = models.TextField(max_length=200)
    start_date = models.DateField('start date')
    end_date = models.DateField('end date')
    status = models.CharField(max_length=20, choices=MY_CHOICES)
    venue = models.ForeignKey(Venue, on_delete=models.CASCADE)
    room = models.CharField(max_length=20)
    delegates_num=models.IntegerField()
    def add_delegate(self):
        #for count, thing in enumerate(args):
        self.delegates_num+=1
    def __str__(self):
        return self.course_name

models.py

 <h1>Registration</h1>
    <form method="POST" class="post-form">{% csrf_token %}
        {{ form.as_p }}

        {% if course.course_name = 'ITIL' %}
            {{ course.delegates_num|inc }}
            {% if course.delegates_num > 15 %}
               <meta http-equiv="refresh" content="1;url=http://example.com">
                     <script type="text/javascript">
                        window.location.href = "https://yr4-group-project-mfblack.c9users.io/sorry_full/"
                </script>
                {% endif %}
        {% endif %}
        <button type="submit" class="save btn btn-default">Save</button>
    </form>

book_course.html

def book_course(request):
    if request.method == "POST":
        form = StudentForm(request.POST)
        if form.is_valid():
            student = form.save(commit=False)
            student.save()
            student.course.add_delegate()
            return redirect('registration_complete')
    else:
        form = StudentForm()
    return render(request, 'website/book_course.html', {'form': form})

views.py

Answer 1

创建房产可能要容易得多，因为我猜测你没有考虑到人们离开课程 - 或者是用户错误的可能性。

检索计数的属性通常是一个小型数据库操作，并且有一些保证是准确的

@property
def delegates_num(self)
   return self.user_set.count()

_{我假设你有一个fk到用户模型或模拟..}

增加models.py和网站中的值会相应地表现

1 个答案: