编辑Django表单集数据，创建新记录，而不是更新

Question

请帮忙

我正在尝试更新一组通过主表单pk与主表单(项目信息(相关的表单集。创建表单运行良好，但我发现实现更新版本极其困难。

对于表单集，我无法理解保存为更新的部分。主窗体会正确更新数据库。表单集只是创建新记录，而不是更新现有记录。我不知道如何实例化表单集。

这是代码。

view.py

@login_required
def edit_project(request):
SampleInformationFormSet = formset_factory(SampleInformationForm, extra=1)
DissolutionMethodsFormSet = formset_factory(DissolutionMethodsForm, extra=1)

form = ProjectInformationForm(request.POST or None)
si_formset = SampleInformationFormSet(request.POST or None, prefix='si')
d_formset = DissolutionMethodsFormSet(request.POST or None, prefix='d')

if request.method == 'POST':
form = ProjectInformationForm(request.POST or None)
si_formset = SampleInformationFormSet(request.POST or None, prefix='si')
d_formset = DissolutionMethodsFormSet(request.POST or None, prefix='d')
pi_pk = ''
p = ''
if form.is_valid():
pi_pk = form.cleaned_data['hd']
p = ProjectInformation.objects.get(pk=pi_pk)
form = ProjectInformationForm(request.POST, instance=p)
form.save()  # This form saves correctly
for si_form in si_formset:
si_form.save() # I do not know how to attach an instance to these formsets
for d_form in d_formset:
d_form.save()

messages.success(request, 'Your project has been updated!')
return redirect('edit_project')
else:
pass
form = ProjectInformationForm(request.POST or None)
si_formset = SampleInformationFormSet(request.POST or None, prefix='si')
messages.warning(request, 'There was an error saving your form.')
study_id_select = list(
ProjectInformation.objects.values('dissolution_study_id', 'id').filter())
context = {'form': form, 'si_formset': si_formset, 'd_formset': d_formset, 'study_id_select': study_id_select}
return render(request, 'main/edit_project.html', context)

models.py我只想把七个模型中的三个模型的一部分包括进来，让它稍微短一点。

class ProjectInformation(models.Model):
username = models.ForeignKey(User, on_delete=models.CASCADE)
compound_code = models.CharField(max_length=60)
product_type = models.ForeignKey(ProductType, on_delete=models.CASCADE)
main_component = models.CharField(max_length=100)
class SampleInformation(models.Model):
sample_index = models.CharField(max_length=30)
sample_type_purpose = models.ForeignKey(SampleTypePurpose, on_delete=models.CASCADE)
specification_number = models.CharField(max_length=20, blank=True, null=True)
project = models.ForeignKey(ProjectInformation, on_delete=models.CASCADE, blank=True, null=True)
class DissolutionMethods(models.Model):
number_of_methods = models.IntegerField(default=1,
validators=[MaxValueValidator(10), MinValueValidator(1)],
blank=True, null=True)
dissolution_method_index = models.CharField(max_length=10)
project = models.ForeignKey(ProjectInformation, on_delete=models.CASCADE, blank=True, null=True)

forms.py

class ProjectInformationForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['hd'] = forms.CharField(widget=forms.HiddenInput, required=False)
class Meta:
model = ProjectInformation
fields = '__all__'
class SampleInformationForm(forms.ModelForm):
class Meta:
model = SampleInformation
fields = '__all__'

如果可以的话，请帮忙。这个项目已经试过了，而且火焰很热！

Answer 1

终于自己解决了。

@login_required
def edit_project(request):
SampleInformationFormSet = formset_factory(SampleInformationForm, extra=1)
DissolutionMethodsFormSet = formset_factory(DissolutionMethodsForm, extra=1)

form = ProjectInformationForm(request.POST or None)
si_formset = SampleInformationFormSet(request.POST or None, prefix='si')
d_formset = DissolutionMethodsFormSet(request.POST or None, prefix='d')

if request.method == 'POST':
form = ProjectInformationForm(request.POST or None)
si_formset = SampleInformationFormSet(request.POST or None, prefix='si')
d_formset = DissolutionMethodsFormSet(request.POST or None, prefix='d')
pi_pk = ''
p = ''
if form.is_valid():
pi_pk = form.cleaned_data['hd']
p = ProjectInformation.objects.get(pk=pi_pk)
form = ProjectInformationForm(request.POST, instance=p)
form.save()
si = p.sampleinformation_set.all()  # All the Methods related to the instance
d = p.dissolutionmethods_set.all()
si_cnt = 0
for si_form in si_formset:
if si_form.is_valid():
update = si_form.save(commit=False)
update.pk = si[si_cnt].pk
update.save()
si_cnt += 1
d_cnt = 0
for d_form in d_formset:
if d_form.is_valid():
update = d_form.save(commit=False)
update.pk = d[d_cnt].pk
update.save()
d_cnt += 1