无法在Django外键字段中插入值

Question

我尝试在django的外键字段中插入值。但这表明我犯了这样的错误：- 无法分配“'95'”：“Catalog.author\u id”必须是“author”实例。 但是，当我尝试使用django shell插入时，它没有显示任何错误，可以正常工作。请帮帮我 我已附上我的代码，你可以很好地理解

型号.py

class Author(models.Model):
    author_id = models.CharField(max_length=50, primary_key=True)
    name = models.CharField(max_length=50)
    city = models.CharField(max_length=50)
    country = models.CharField(max_length=50)

    def __str__(self):
        return str(self.author_id)


class Catalog(models.Model):
    book_id = models.IntegerField(primary_key=True)
    title = models.CharField(max_length=100)
    year_of_publish = models.CharField(max_length=5)
    price = models.IntegerField()
    author_id = models.ForeignKey('Author', on_delete=models.CASCADE, null=True)

    def __str__(self):
        return str(self.book_id)

Forms.py

class Catalog_Details(forms.ModelForm):
book_id = forms.CharField(widget=forms.TextInput(
    attrs={'class': 'form-control',
           'placeholder': 'Enter book id'}
), required=True, max_length=50)

title = forms.CharField(widget=forms.TextInput(
    attrs={'class': 'form-control',
           'placeholder': 'Enter title'}
), required=True, max_length=50)
year_of_publish = forms.CharField(widget=forms.TextInput(
    attrs={'class': 'form-control',
           'placeholder': 'Enter Published Year'}
), required=True, max_length=5)
author_id = forms.ModelChoiceField(queryset=Author.objects.values_list(
    'author_id', flat=True))

price = forms.CharField(widget=forms.TextInput(
    attrs={'class': 'form-control',
           'placeholder': 'Enter Price'}
), required=True, max_length=50)

class Meta():
    model = Catalog
    fields = ['book_id', 'title', 'year_of_publish', 'price', 'author_id']

视图.py

@login_required
def catalog(request):
    if request.user.is_authenticated:
        if request.method == 'POST':
            form = Catalog_Details(request.POST)
            if form.is_valid():
                author_id = form.cleaned_data['author_id']
                m = Author.objects.get(author_id=author_id)
                c1 = Catalog(book_id=form.cleaned_data['book_id'], title=form.cleaned_data['title'],
                           year_of_publish=form.cleaned_data['year_of_publish'],price=form.cleaned_data['price'], author_id=m)
                c1.save()
                form = Catalog_Details()

        else:
            form = Catalog_Details()
        return render(request, 'catalog.html', {'form': form})

Answer 1

我认为甚至没有必要重写表单中的author_id字段。您可以从Catalog_Details中删除author_id。您可以如下方式更新视图：

@login_required
def catalog(request):
    if request.method == 'POST':
        form = Catalog_Details(request.POST)
        if form.is_valid():
            form.save()
            form = Catalog_Details()
            # here you should redirect to a success page to know `Catalog_Details` has been created
    else:
        form = Catalog_Details()
    return render(request, 'catalog.html', {'form': form})

FYI，您不应该用后缀_id命名ForeignKey字段，因为django为您创建了后缀。例如：在本例中，您将在Catalog模型中找到一个字段author_id_id，该字段将返回一个整数值（Author表列的主键）