Question

我有一个Trip模型，并创建了一个表格，以便更新现有行程。

models.py：

class Trip(models.Model):
    trip_id = models.CharField(max_length=20, verbose_name="Ref. Viagem")
    destination = models.CharField(max_length=200, null=True, verbose_name='Destino')
    client = models.ForeignKey(Clients, null=True, on_delete=models.CASCADE, verbose_name="Cliente")
    out_flight = models.ForeignKey(Flight, related_name="outbound_flight" ,null=True, on_delete=models.SET_NULL, verbose_name="Voo Ida")
    hotel = models.ForeignKey(Hotels, null=True, on_delete=models.SET_NULL, verbose_name="Hotel")
    in_flight = models.ForeignKey (Flight, related_name="inbound_flight", null=True, on_delete=models.SET_NULL, verbose_name="Voo Regresso")

forms.py：

class UpdateTrip(ModelForm):

    def __init__(self, *args, **kwargs):
        super(UpdateTrip, self).__init__(*args, **kwargs)
        self.fields['trip_id'].widget = TextInput(attrs={'class': 'form-control'})
        self.fields['destination'].widget = TextInput(attrs={'class': 'form-control'})
        self.fields['client'].queryset = Clients.objects.all()


    class Meta:
        model = Trip
        fields = ('trip_id', 'destination', 'client', 'out_flight', 'hotel', 'in_flight')

这是views.py：

def trip_upd(request, trip_id):
    if request.method == 'POST':
        form = UpdateTrip(request.POST)
        if form.is_valid():
            form.save()
            return redirect('trips')
    else:
        form = UpdateTrip()
    return render(request, 'backend/trip_update.html', {'form': form})

我在测试时使用准系统表格：

<form method="post">
    {% csrf_token %}
    {{ form }}
    <input type="submit" value="Submit">
</form>

现在，这不会更新对象，而是创建一个新对象。

Answer 1

您需要通过instance=…参数传递要更新的实例：

def trip_upd(request, trip_id):
    if request.method == 'POST':
        trip = Trip.objects.get(trip_id=trip_id)
        form = UpdateTrip(request.POST, instance=trip)
        if form.is_valid():
            form.save()
            return redirect('trips')
    else:
        form = UpdateTrip()
    return render(request, 'backend/trip_update.html', {'form': form})

或者如果对象不存在，您可以使用get_object_or_404 function [Django-doc]返回HTTP 404错误：

from django.shortcuts import get_object_or_404

def trip_upd(request, trip_id):
    if request.method == 'POST':
        trip = get_object_or_404(Trip, trip_id=trip_id)
        form = UpdateTrip(request.POST, instance=trip)
        if form.is_valid():
            form.save()
            return redirect('trips')
    else:
        form = UpdateTrip()
    return render(request, 'backend/trip_update.html', {'form': form})

请注意，在表单中，您可以在Meta中指定小部件，这要比在__init__中编写小部件：

class UpdateTrip(ModelForm):

    class Meta:
        model = Trip
        fields = ('trip_id', 'destination', 'client', 'out_flight', 'hotel', 'in_flight')
        widgets = {
            'trip_id': TextInput(attrs={'class': 'form-control'}),
            'destination': TextInput(attrs={'class': 'form-control'})
        }

更新表单在Django中创建新对象

1 个答案: