Python 如何从两个模型中更新多对多？

你好，我正在尝试更新两个模型中的多对多字段。我可以成功地从集群模型更新带有M2M字段的集群模型，但无法从子网模型更新它

我将在子网的模板表单中得到一个集群列表。。。布乌特

分配给子网的群集未显示选中状态

当我选择集群并更新表单时，它不会将子网添加到集群

现在我想我只能从集群端更新m2m关系，我说的对吗

型号.py

class Cluster(models.Model):
    cluster = models.CharField(max_length=130, unique=True)
    subnet = models.ManyToManyField('Subnet', null=True, blank=True)

class Subnet(models.Model):
    network_address = models.IPAddressField()
    subnet_prefix = models.ForeignKey('SubnetPrefix')

class SubnetForm(forms.ModelForm):
    cluster = forms.ModelMultipleChoiceField(widget=forms.CheckboxSelectMultiple, required=True, queryset=Cluster.objects.all())

def __init__(self, *args, **kwargs):
    self.helper = FormHelper()
    self.helper.form_tag = True
    self.helper.layout = Layout(
        Div(
            Div(Field('network_address', css_class="input-sm"), css_class="col-lg-4"),
            Div(Field('subnet_prefix', css_class="input-sm"), css_class="col-lg-2"),
            css_class="row"
        ),
        Div(
            Div(Field('cluster', css_class="nav nav-list"), css_class="col-lg-4"),
            css_class="row"
        ),
        Div(
            Div(
                Submit('submit', 'Submit'),
            ),
            css_class="row",
        ),
    )
    super(SubnetForm, self).__init__(*args, **kwargs)

    class Meta:
        model = Subnet

class SubnetUpdateView(UpdateView):
    template_name = 'subnet_update.html'
    model = Subnet
    form_class = SubnetForm
    success_url = '#'

    def form_valid(self, form):
        messages.success(self.request, u"Subnet updated successfully.")
        return super(SubnetUpdateView, self).form_valid(form)

forms.py

class Cluster(models.Model):
    cluster = models.CharField(max_length=130, unique=True)
    subnet = models.ManyToManyField('Subnet', null=True, blank=True)

class Subnet(models.Model):
    network_address = models.IPAddressField()
    subnet_prefix = models.ForeignKey('SubnetPrefix')

class SubnetForm(forms.ModelForm):
    cluster = forms.ModelMultipleChoiceField(widget=forms.CheckboxSelectMultiple, required=True, queryset=Cluster.objects.all())

def __init__(self, *args, **kwargs):
    self.helper = FormHelper()
    self.helper.form_tag = True
    self.helper.layout = Layout(
        Div(
            Div(Field('network_address', css_class="input-sm"), css_class="col-lg-4"),
            Div(Field('subnet_prefix', css_class="input-sm"), css_class="col-lg-2"),
            css_class="row"
        ),
        Div(
            Div(Field('cluster', css_class="nav nav-list"), css_class="col-lg-4"),
            css_class="row"
        ),
        Div(
            Div(
                Submit('submit', 'Submit'),
            ),
            css_class="row",
        ),
    )
    super(SubnetForm, self).__init__(*args, **kwargs)

    class Meta:
        model = Subnet

class SubnetUpdateView(UpdateView):
    template_name = 'subnet_update.html'
    model = Subnet
    form_class = SubnetForm
    success_url = '#'

    def form_valid(self, form):
        messages.success(self.request, u"Subnet updated successfully.")
        return super(SubnetUpdateView, self).form_valid(form)

视图.py

class Cluster(models.Model):
    cluster = models.CharField(max_length=130, unique=True)
    subnet = models.ManyToManyField('Subnet', null=True, blank=True)

class Subnet(models.Model):
    network_address = models.IPAddressField()
    subnet_prefix = models.ForeignKey('SubnetPrefix')

class SubnetForm(forms.ModelForm):
    cluster = forms.ModelMultipleChoiceField(widget=forms.CheckboxSelectMultiple, required=True, queryset=Cluster.objects.all())

def __init__(self, *args, **kwargs):
    self.helper = FormHelper()
    self.helper.form_tag = True
    self.helper.layout = Layout(
        Div(
            Div(Field('network_address', css_class="input-sm"), css_class="col-lg-4"),
            Div(Field('subnet_prefix', css_class="input-sm"), css_class="col-lg-2"),
            css_class="row"
        ),
        Div(
            Div(Field('cluster', css_class="nav nav-list"), css_class="col-lg-4"),
            css_class="row"
        ),
        Div(
            Div(
                Submit('submit', 'Submit'),
            ),
            css_class="row",
        ),
    )
    super(SubnetForm, self).__init__(*args, **kwargs)

    class Meta:
        model = Subnet

class SubnetUpdateView(UpdateView):
    template_name = 'subnet_update.html'
    model = Subnet
    form_class = SubnetForm
    success_url = '#'

    def form_valid(self, form):
        messages.success(self.request, u"Subnet updated successfully.")
        return super(SubnetUpdateView, self).form_valid(form)

subnet\u update.html

{% extends 'base.html' %}
{% load crispy_forms_tags %}

{% block content %}
    <h1>Update Subnet</h1>
    <br />
        {% crispy form %}
    <br />
{% endblock %}

{%extends'base.html%}
{%load crispy_forms_tags%}
{%block content%}
更新子网


{%crispy form%}


{%endblock%}

群集表单的html输出

<div class="row" >
<div class="col-lg-4" >
<div id="div_id_cluster" class="form-group">
    <label for="id_cluster_0" class="control-label  requiredField">Cluster<span class="asteriskField">*</span></label>
    <div class="controls " class="nav nav-list">
        <label class="checkbox"><input type="checkbox" name="cluster" id="id_cluster_1" value="1"  class="nav nav-list">CLUSTER01</label>
        <label class="checkbox"><input type="checkbox" name="cluster" id="id_cluster_2" value="2" class="nav nav-list">CLUSTER02</label>
        <label class="checkbox"><input type="checkbox" name="cluster" id="id_cluster_3" value="3"  class="nav nav-list">CLUSTER03</label>
    </div>
</div>
</div>
</div>

簇*
集群01
集群02
集群03

这似乎是以下内容的副本：

第一个答案不会改变模型，并向您展示了如何使init和save方法复杂化以使您的modelforms工作

---

第二个答案是通过模型明确定义自己的m2m，从而使表单保持简单。

这里没有真正重要的代码。用于更新模型的代码在哪里？它在我的视图SubnetUpdateView中，在调用form_valid方法后，它会自动保存。通过def form_valid（self，form）查看ModelFormMixin:at。