在Django和Django Rest Framework中使用一个请求创建多个对象

时间:2017-04-16 08:22:25

标签: django django-rest-framework

我使用Django作为后端服务器,使用Vue.js作为前端电影应用。

我有一个Ticket模型

class MovieTicket(models.Model):
    show = models.ForeignKey(Show)
    seat = models.ForeignKey(Seat)
    user = models.ForeignKey(User)
    purchased_at = models.DateTimeField(default=timezone.now)
    qrcode = models.ImageField(upload_to='qrcode', blank=True, null=True)
    qrcode_data = models.CharField(max_length=255, unique=True, blank=True)

    class Meta:
        unique_together = ('show', 'seat')

及其相关的Serializer

class MovieTicketSerializer(serializers.ModelSerializer):
    class Meta:
        model = MovieTicket
        fields = '__all__'

要购买新的Ticket,会有一个映射到此网址的视图 http://dev.site.com/api/movies/buy-ticket/

@api_view(['POST'])
@permission_classes([IsAuthenticated])
def buy_ticket(request):
    serialized = MovieTicketSerializer(data=request.data)
    if serialized.is_valid():
        serialized.save()
        return Response(serialized.data, status=status.HTTP_201_CREATED)
    return Response(serialized._errors, status=status.HTTP_400_BAD_REQUEST)

现在从前端(Vue.js)我可以创建一个新的电影票:

const formBody = {
    show: this.$store.state.showSelected.showTime.id,
    user: this.$store.state.user.id,

    // selectedSeats is an array of seats that have been selected by the user. Here I am passing the first seat object.
    seat: this.$store.state.selectedSeats[0].seat.id
};

this.$http.post("http://dev.site.com/api/movies/buy-ticket/", formBody)
    .then(function (response) {
        console.log(response.data);
    })
    .catch(function (response) {
        console.log(response);
    });
return;

如果表单有效,这将创建一个新的MovieTicket对象,否则显示错误/。

现在,假设用户选择了多个席位,我可以遍历每个selectedSeats阵列,并在客户端获取座位ID。并张贴这样的东西:

{
    "purchased_at": null,
    "qrcode": null,
    "qrcode_data": "",
    "show": 11,
    "seat": [
        106,
        219
    ],
    "user": 34
}

但我感到困惑的是,如果Django休息框架只接受每个请求一个席位并相应地显示错误,我怎么能传递多个seat.id?如果故障单可用,则显示错误,以及是否为该show-seat创建电影票。

5 个答案:

答案 0 :(得分:11)

使用many = True

初始化序列化程序

在您的实施中,这很容易实现:

serialized = MovieTicketSerializer(data=request.data, many=True)

数据不是单个对象,而是一个对象数组。

您的信息提示您需要转换request.data以生成这些多个对象(所有相同的数据只是不同的座位号)。正确?

反正:

请参阅:How do I create multiple model instances with Django Rest Framework?

编辑:

这里是drf docu中的信息:http://www.django-rest-framework.org/api-guide/serializers/#dealing-with-multiple-objects

(强烈建议在编写第一个真正的实现之前,从上到下阅读drf文档,然后再玩它。有很多方法可以使用drf,并且知道所有这些都会导致更好的决策)

编辑2(问题更新后):

您可以从客户端发送此JSON(请参阅下文),或者在您致电buy_ticket(request)之前,使用MovieTicketSerializer(...,many=True)方法中客户端发送的当前JSON创建此格式:

[
    {
        "purchased_at": null,
        "qrcode": null,
        "qrcode_data": "",
        "show": 11,
        "seat": 106,
        "user": 34
    },
    {
        "purchased_at": null,
        "qrcode": null,
        "qrcode_data": "",
        "show": 11,
        "seat": 219,
        "user": 34
    }
]

答案 1 :(得分:2)

您可以查看视图功能中的座位数,并创建一个或多个票证:

@api_view(['POST'])
@permission_classes([IsAuthenticated])
def buy_ticket(request):
    # Check if seats is a list
    if isinstance(request.data['seat'], list):
        seats = request.data.pop('seat')
        models = []
        for seat in seats:
            # validate each model with one seat at a time
            request.data['seat'] = seat
            serializer = MovieTicketSerializer(data=request.data)
            serializer.is_valid(raise_exception=True)
            models.append(serializer)
        # Save it only after all seats are valid. 
        # To avoid situations when one seat has wrong id 
        # And you already save previous
        saved_models = [model.save() for model in models]
        result_serializer = MovieTicketSerializer(saved_models, many=True)
        # Return list of tickets
        return Response(result_serializer.data)
    # Save ticket as usual
    serializer = MovieTicketSerializer(data=request.data)
    serializer.is_valid(raise_exception=True)
    return Response(serializer.data)

它会起作用但老实说它真是一团糟。您可以在不同的功能中移动创建座位的逻辑,它看起来会更好。

答案 2 :(得分:0)

如果您希望用户能够为一个故障单选择多个席位,则最好删除SeatMovieTicket的一对一映射,并创建多个席位关系。像这样:

串行器:

class SeatSerializer(serializers.ModelSerializer):
    class Meta:
        model = Seat

class MovieTicketSerializer(serializers.ModelSerializer):
    seats = SeatSerializer(many=True)
    class Meta:
        model = MovieTicket
        fields = '__all__'

    def create(self, vlaidated_data):
        seats = validated_data.pop('seats')
        instance = MovieTicket.objects.create(
            **validated_data)

        for seat in seats:
            Seat.objects.create(
                movieticket=instance, **seats)

        return instance

模型应该如下:

class MovieTicket(models.Model):
    show = models.ForeignKey(Show)
    user = models.ForeignKey(User)
    purchased_at = models.DateTimeField(default=timezone.now)
    qrcode = models.ImageField(upload_to='qrcode', blank=True, null=True)
    qrcode_data = models.CharField(max_length=255, unique=True, blank=True)

class Seat(models.Model):
    movieticket = ForeignKey(
        MovieTicket, related_name="movieticket")

    # ... other fields.

然后,这将允许您传递一系列席位'在请求中。

答案 3 :(得分:0)

如果您不介意在django项目中添加其他应用,可以尝试使用django-rest-framework-bulk,否则可以查看代码并查看其实现方式。

如果您使用此应用程序,则可以通过在POST请求中发送元素列表来执行批量创建操作。

e.g:

[{'name': 'Jane'}, {'name': 'John'}, {'name': 'Johny'}]

答案 4 :(得分:0)

This answer是解决这个问题的一个非常好的解决方案:

您只需覆盖APIView中的get_serializer方法,然后将many=True传递到基本视图的get_serializer,如下所示:

class SomeAPIView(CreateAPIView):
    queryset = SomeModel.objects.all()
    serializer_class = SomeSerializer

    def get_serializer(self, instance=None, data=None, many=False, partial=False):
        return super(SomeAPIView, self).get_serializer(instance=instance, data=data, many=True, partial=partial)