Python 在django中同时保存多个数据，如复选框

我在ang django项目在线投票中工作。在我的模板中，我使用 循环以循环所有位置和候选人。我在一个属性中一次保存多个数据时遇到问题，例如，在我的模型中，我有：

class Vote(models.Model):
candidate_id = models.ForeignKey('Candidate', blank=True, null=True)
election_id = models.ForeignKey('Election', blank=True, null=True)
user_id = models.ForeignKey('User', blank=True, null=True)

def __str__(self):
    return "%s %s" % (user_id.first_name, election_id.year)

在my template vote.html中：

<form method="POST" class="form-horizontal" role="form">

                              {% if success %}
                                <div class="alert alert-success">
                                  <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
                                  <strong>Success!</strong> {{ success }}
                                </div>
                              {% endif %}

                              {% if exist %}
                              <div class="alert alert-warning">
                                <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
                                <strong>Warning!</strong> {{ exist }}
                              </div>
                              {% endif %}

                              {% csrf_token %}
                                  <div class="form-group ">
                                  {% for position in positions %}
                                      <label for="cname" class="control-label col-lg-2">{{ position }}<span class="required">*</span></label>

                                      {% for candidate in candidates %}
                                        {% if position.pk == candidate.position_id.pk %}
                                          <div class="col-lg-3">
                                              <input type="checkbox" name="candidate_id" value="{{ candidate.pk }}">{{ candidate }}<br>
                                          </div>
                                        {% endif %}
                                      {% endfor %}

                                  </div>
                                  {% endfor %}
                                          <button class="btn btn-primary" type="submit">Save</button>
                                          <button class="btn btn-default" type="button">Cancel</button>
                                      </div>
                                  </div>
                              </form>

---

为什么在更改每个字段后保存投票？设置好所有字段后保存不会改变这里的任何内容。因为我需要一次获得他们所有的赌注并保存它。比如总统和副总统。之后，将其交给views.py并保存在candidate_id属性中。

def vote(request):

if request.user.is_authenticated and request.user.is_admin:
    candidates = Candidate.objects.all()
    election = Election.objects.all().filter(is_active=True)
    positions = Position.objects.all()
    user = get_object_or_404(User, pk=request.user.pk)

    try:
        if request.method == 'POST':
            candidate_id = request.POST['candidate_id']

            vote = Vote.objects.create(candidate_id=candidate_id)
            vote.save()

            vote.election_id = election
            vote.save()

            vote.user_id = user
            vote.save()

        else:
            form = VoteForm()
            return render(request,'system/vote.html', {'form':form, 'candidates': candidates,
                                                        'election': election, 'user': user,
                                                        'positions': positions})

    except:
        exist = "ERROR!"
        form = VoteForm()
        return render(request,'system/vote.html', {'form':form, 'exist': exist})

elif not request.user.is_authenticated:
    return redirect('system.views.user_login')