Question

models.py：

class MODEL(models.Model):
    ModelName = models.CharField(max_length = 128, unique = True)
    URL_Slug = models.SlugField(unique = True)
    ...

class Maker(models.Model):
    maker = models.CharField(max_length = 128, unique = True)
    URL_Slug = models.SlugField(unique = True)
    ...
class Truck(models.Model):
    MODEL = models.ForeignKey(MODEL)
    CarID = models.CharField(max_length = 10, unique = True, null = False)
    Maker = models.ForeignKey(Maker)   
    year = models.IntegerField(default = 0)
    def __unicode__(self):
        return self.CarID

forms.py：

class MODELForm(forms.ModelForm):
    ModelName = forms.CharField(max_length = 128, help_text = 'Enter the NEW model name')
    URL_Slug = forms.SlugField(widget = forms.HiddenInput(), required = False)

    class Meta:
        model = MODEL
        fields = ('ModelName', )

class MakerForm(forms.ModelForm):
    maker = forms.CharField(max_length = 128, help_text = 'Enter the NEW maker')
    URL_Slug = forms.SlugField(widget = forms.HiddenInput(), required = False)

    class Meta:
        model = Maker
        fields = ('maker', )

class TruckForm(forms.ModelForm):
    MODEL = forms.CharField(max_length = 128, help_text = 'Enter the NEW model name')
    CarID = forms.CharField(max_length = 10, help_text = 'Enter the NEW truck ID')
    Maker = forms.CharField(max_length = 128, help_text = 'Enter the NEW maker')   
    year = forms.IntegerField(help_text = 'Enter the year of production')

    class Meta:
        model = Truck
        fields = ('MODEL', 'CarID', 'Maker', 'year')

views.py：

def add_Truck(request):
    form = TruckForm()

    if request.method == 'POST':
        form = TruckForm(request.POST)
        if form.is_valid():
            form.save(commit = True)
            return index(request)

        else:
            print(form.errors)
    return render(request, 'APP/addTruck.html', {'form': form})

HTML文件：

<!DOCTYPE html>
<html>
    <body>
        <div>
            <form id = "Truck" method = "post" action = "/APP/NewTruck/">
                {%csrf_token%}
                {% for field in form.visible_fields %}
                    {{field.errors}}
                    {{field.help_text}}
                    {{field}}<br/>
                {% endfor %}
                <input type = "submit" name = "submit" value = "Create Truck">
            </form>
        </div>
    </body>
</html>

我正在尝试在addTruck.html中创建一个新对象，因为MODEL和Maker是外键，因此在创建Truck对象时，MODEL和Maker字段也应该是对象。

回溯：

这是来自终端Macbook的Traceback：

-

[07 / Aug / 2017 09:14:04]＆＃34; GET / APP / NewTruck / HTTP / 1.1＆＃34; 200 1240
  内部服务器错误：/ APP / NewTruck / Traceback（最近的呼叫
  最后）：文件
  ＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/handlers/exception.py" ;,   第39行，在内部          response = get_response（request）File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/handlers/base.py"，   第187行，在_get_response中          response = self.process_exception_by_middleware（e，request）文件
  ＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/core/handlers/base.py" ;,   第185行，在_get_response中          response = wrapped_callback（request，* callback_args，** callback_kwargs）File＆＃34; /Users/apple/WebWorkshop/TKTrading/APP/views.py" ;,第88行，中
  add_Truck          if form.is_valid（）：File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/forms/forms.py"，   第169行，in_valid          返回self.is_bound而不是self.errors文件＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/forms/forms.py"，   第161行，有错误          self.full_clean（）File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/forms/forms.py"，   第372行，在full_clean中          self._post_clean（）File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/forms/models.py"，   第388行，在_post_clean中          self.instance = construct_instance（self，self.instance，opts.fields，opts.exclude）文件
  ＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/forms/models.py" ;,   第60行，在construct_instance中          f.save_form_data（instance，cleaning_data [f.name]）File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/ 初始化的.py＆＃34 ;,   第833行，在save_form_data中          setattr（instance，self.name，data）File＆＃34; /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/db/models/fields/related_descriptors.py&# 34 ;,   第211行，设置          self.field.remote_field.model._meta.object_name，ValueError：无法分配＆＃34;你＆＃39; Wing＆＃39;＆＃34;＆＃34; Truck.MODEL＆＃34;必须是＆＃34; MODEL＆＃34;实例。
  [07 / Aug / 2017 09:14:42]＆＃34; POST / APP / NewTruck / HTTP / 1.1＆＃34; 500 93290

Answer 1

在TruckForm，

中

MODEL = forms.CharField(max_length = 128, help_text = 'Enter the NEW model name')

在你的模特中，

MODEL = models.ForeignKey(MODEL)

ForeignKey字段必须是相应模型的实例，而不是纯文本。错误消息非常具体。在您的情况下，如果您想每次为新卡车创建新模型，您可能需要覆盖save()方法，因为适当的原因。或者如果你想从现有的ModelForm中选择一个模型，你可以让Django使用该字段的默认选择小部件，或者你也可以通过定义一个自定义小部件来覆盖它。

MODELs

-Django-得了＆＃34;不能分配＆＃34;你＆＃39; Wing＆＃39;＆＃34;＆＃34; Truck.MODEL＆＃34;必须是＆＃34; MODEL＆＃34;实例＆＃34;在为数据库

1 个答案: