Django表单在尝试从数据库更新现有行时未验证

我正在做我的第一个Django项目。 但我发现以下错误:

编辑\u文件模板

                <form method="POST" action="{% url 'edit_file' file.id %}">
                {% csrf_token %}

                {{ form.errors }}
                {{ form.non_field_errors }}

                {% for hidden_field in form.hidden_fields %}
                    {{ hidden_field.errors }}
                    {{ hidden_field }}
                {% endfor %}

                <div class="form-group row">
                    <label for="id_name" class="col-sm-3 col-form-label"> File Name </label>
                    <div class="col-sm-4">
                        {% render_field form.name|add_class:"form-control" %}
                    </div>
                </div>

                <div class="form-group row">
                    <label class="col-sm-3 col-form-label">File Path</label>
                    <div class="col-sm-4">
                        {% render_field form.directory_path|add_class:"form-control" %}
                    </div>
                </div>

                <div class="form-group">
                    {% render_field form.script_code|add_class:"form-control" %}
                    <pre id="id_script_code" style="height: 40pc;">{{ form.script_code }}</pre>
                </div>

                <button type="submit" class="btn btn-success mr-2">Save Changes</button>
                <a href="{% url 'list_files_from_version' file.version_id %}" class="btn btn-light">Back</a>

            </form>

视图。py公司

def edit_file(request, id):
    instance = get_object_or_404(File, id=id)
    if request.method == "POST":
        form = EditFileForm(request.POST, instance=instance)  
        if form.is_valid():
            print('Form validation => True')
            form.save()
            return HttpResponse('<h1> database updated! </h1>')
        else:
            print('Form validation => False')
        file = File.objects.latest('id')
        context = {'file': file, "form": form}
        return render(request, 'edit_file.html', context)
    else:
        instance = get_object_or_404(File, id=id)
        form = EditFileForm(request.POST or None, instance=instance)
        file = File.objects.latest('id')
        context = {'file': file, "form": form}
        return render(request, 'edit_file.html', context)

表格。py公司

class EditFileForm(ModelForm):
    # field_order = ['field_1', 'field_2']

    class Meta:
        print("forms.py 1")
        model = File
        fields = ('name', 'script_code', 'directory_path','version')

    def clean(self):
        print("forms.py 2")
        cleaned_data = super(EditFileForm, self).clean()
        name = cleaned_data.get('name')
        print("cleaned data: ", cleaned_data)

型号:

版本id指向包含多个文件的版本。

  class File(models.Model):
    # Incrementing ID (created automatically)
    name = models.CharField(max_length=40)
    script_code = models.TextField()  # max juiste manier?
    directory_path = models.CharField(max_length=200)
    version = models.ForeignKey('Version', on_delete=models.CASCADE)

    class Meta(object):
        db_table = 'file'  # table name


class Version(models.Model):
    # Incrementing ID (created automatically)
    version_number = models.CharField(max_length=20)
    pending_update = models.BooleanField(default=False)
    creation_date = models.DateTimeField(auto_now_add=True, null=True, editable=False)
    modification_date = models.DateTimeField(auto_now_add=True, null=True)
    connecthor = models.ForeignKey('ConnecThor', on_delete=models.CASCADE)

    def __str__(self):
        return self.connecthor_id

问题是:

类型is\u valid()不断失败。我的视图返回一个错误。 *版本:此字段为必填字段。 但我不知道怎么解决这个问题。用户应该只能更新5个数据字段中的3个。因此,没有理由在模板中显示PK或FK。