ManyToMany 不会保存到 db Django

Question

我有一个多对多字段，结果CheckboxSelectMultiple没有保存在数据库中，我不明白为什么。这一定很简单，但是......

这是代码：

模型.py

class Person(models.Model):

    last_name = models.CharField(max_length = 50)
    first_name = models.CharField(max_length = 50)

    def __str__(self):
        return self.last_name +" "+self.first_name

class Event(models.Model):
        owner = models.ForeignKey(User, on_delete=models.SET_NULL, null = True)
        person = models.ManyToManyField(Person)

表格.py

class EventForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        self.user = kwargs.get('user',None)
        #self.user = kwargs.pop('user',None)
        super(EventForm, self).__init__(*args, **kwargs)

        self.helper = FormHelper()
        self.helper.form_method = 'POST'
        #self.helper.form_action = reverse_lazy('simpleuser')
        self.helper.add_input(Submit('submit', 'Submit', css_class='btn-success'))     

    class Meta:
        model = Event
        fields = ['person']
        widgets ={
        'person': forms.CheckboxSelectMultiple,
        }

视图.py

def uploadevent(request):

    if request.method == "POST":
        form =EventForm(request.POST)
        if form.is_valid():
            event = form.save(commit=False)
            event.owner = request.user
            event.save()
    else:
        form = EventForm()

    return render...

Answer 1

请参阅此 stackoverflow 问题的回复：通过 Django 中的模型表单保存多对多数据

引用 OP：

使用 commit=False 时，必须调用 save_m2m()

m2m 关系需要先保存父对象，而使用 commit=False 而不是这样做

只需在下面添加这一行 event.save()

    if form.is_valid():
        event = form.save(commit=False)
        event.owner = request.user
        event.save()
        form.save_m2m()

参考：https : //docs.djangoproject.com/en/2.0/topics/forms/modelforms/#the-save-method