Django 将一些字段保存到数据库中，但不保存其他字段

Question

我正在尝试通过表单保存一些数据，我正在尝试使用FormSet.要保存的数据是包含Product的发票 而且Details.

我能够在一个地方渲染所有内容(这并不简单(和 将发票和详细信息保存到数据库。出于某种原因，Detail表保存的是产品 ID，但不保存发票 ID。 这是 我的models.py：

class Detail(models.Model):
invoice = models.ForeignKey(Invoice, null=True, on_delete=models.CASCADE)
product = models.ForeignKey(Product, on_delete=models.CASCADE)
quantity = models.PositiveIntegerField(default=1)
subtotal = models.DecimalField(max_digits=9 , null=True, decimal_places=2)
class Invoice(models.Model):
date = models.DateField(default=datetime.date.today)
number = models.CharField(max_length=10, default='0000000000')
supplier = models.ForeignKey(Supplier, on_delete=models.CASCADE)
products = models.ManyToManyField(Product, null=True, blank=True)
total = models.DecimalField(max_digits=9 , null=True, decimal_places=2)

这是我的views.py：

def invoice_new(request):
DetailFormSet = formset_factory(DetailForm, extra=2)
if request.method == "POST":
invoice_form = InvoiceForm(request.POST)
detail_formset = DetailFormSet(request.POST)
if invoice_form.is_valid() and detail_formset.is_valid():
invoice = invoice_form.save(commit=False)
invoice.save()
for details in detail_formset:
details.save()
return redirect('invoice_detail', pk=invoice.pk)
else:
return redirect('invoice_error')
else:
invoice_form = InvoiceForm()
detail_formset=formset_factory(DetailForm, extra=2)
return render(request, 'invoice/invoice_edit.html', {'invoice_form': invoice_form, 'detail_form': detail_formset} )

我尝试将其添加到for循环的主体中：

details.invoice_id = invoice.pk

invoice.id打印正常，但不会将数字保存到数据库。我不明白它如何很好地获取产品 ID，但不是发票。

我正在添加forms.py

class InvoiceForm(forms.ModelForm):
class Meta:
model = Invoice
fields = ['date','number','supplier']
total = forms.DecimalField(disabled=True)
class DetailForm(forms.ModelForm):
class Meta:
model = Detail
fields = ['product','quantity']

Answer 1

您可以在保存表单之前设置发票 ID。

if invoice_form.is_valid() and detail_formset.is_valid():
invoice = invoice_form.save(commit=False)
invoice.save()
for details in detail_formset:
details.invoice = invoice # Set the invoice
details.save()