Django Rest Framework外键序列化

Question

我有以下型号:

class Geofence(models.Model):
    id = models.IntegerField(default=0, primary_key=True)
    name = models.CharField(max_length=200, default="Geofence", blank=False)
    lat = models.DecimalField(default=0, decimal_places=6, max_digits=10, blank=False)
    long = models.DecimalField(default=0, decimal_places=6, max_digits=10, blank=False)
    radius = models.IntegerField(default=10, blank=False)

    def __str__(self):
        return "Geofence: " + str(self.name);

class Checkpoint(models.Model):
    id = models.IntegerField(default=0, primary_key=True)
    name = models.CharField(max_length=200, default="Geofence", blank=False)
    geofence = models.ForeignKey(Geofence, related_name='geofence')
    lat = models.DecimalField(default=0, decimal_places=6, max_digits=10, blank=False)
    long = models.DecimalField(default=0, decimal_places=6, max_digits=10, blank=False)
    trip_id = models.IntegerField(default=0, blank=False)
    enter_time = models.DateTimeField("Enter Time", blank=False)
    start_time = models.DateTimeField("Start Time", blank = True, null=True)
    stop_time = models.DateTimeField("Stop Time", blank= True, null = True)

和他们各自的序列化器:

class GeofenceSerializer(serializers.ModelSerializer):
    id = serializers.IntegerField(min_value=0)
    name = serializers.CharField()
    lat = serializers.DecimalField(max_digits=10, decimal_places=6, coerce_to_string=False)
    long = serializers.DecimalField(max_digits=10, decimal_places=6, coerce_to_string=False)
    radius = serializers.IntegerField(min_value=0)
    class Meta:
        model = Geofence
        fields = ('id', 'name','lat', 'long', 'radius')

    def create(self, valid_data):
        return Geofence.objects.create(**valid_data)

    def update(self, instance, valid_data):
        instance.id = valid_data.get('id', instance.id)
        instance.name = valid_data.get('name', instance.name)
        instance.name = valid_data.get('lat', instance.lat)
        instance.long = valid_data.get('long', instance.long)
        instance.radius = valid_data.get('radius', instance.radius)
        instance.save()



class CheckpointSerializer(serializers.ModelSerializer):
    lat = serializers.DecimalField(max_digits=10, decimal_places=6, coerce_to_string=False)
    long = serializers.DecimalField(max_digits=10, decimal_places=6, coerce_to_string=False)
    enter_time = serializers.DateTimeField()
    start_time =serializers.DateTimeField()
    geofence = serializers.SlugRelatedField(many=False, slug_field="id", read_only=True)
    class Meta:
        model = Checkpoint
        fields = ('trip_id', 'geofence', 'start_time', 'stop_time', 'lat', 'long', 'enter_time')

我从滑块中获取日期时间并进行ajax调用以获取相关数据.服务器响应500错误.具体来说,错误"KeyError:geofence"

这是被称为的视图:

class ResultsView(APIView):
    model = Checkpoint
    serializer_class = CheckpointSerializer
    def get(self, request, start, end):
        begin_date = parse_datetime(request.GET["start"]) 
        end_date = parse_datetime(request.GET["end"])
        ids = Checkpoint.objects.filter(start_time__range=(begin_date,end_date)).filter(stop_time__range=(begin_date,end_date)).distinct().values('trip_id', 'lat', 'long', 'enter_time')
        serializer = CheckpointSerializer(ids, many=True)
        return Response(serializer.data)

    def post(self, request, format=None):
        request.data["id"] = uuid.uuid4().int & (1<<8)-1
        serializer = CheckpointSerializer(data= request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)
        return Response(serializer.error)

和角度调用:

$http.get("http://127.0.0.1:8000/traffic/get/?end=" + $scope.endDateTime + "&format=json&search=Search&start=" + $scope.startDateTime)
  .then(function(response) {
     console.log("Response: " + response.data)
       $scope.data = response.data;
   });

我相信问题是序列化程序中的外键:

geofence = serializers.SlugRelatedField(many=False, slug_field="id", read_only=True)

这是在django rest框架中序列化外键的正确方法吗？如果没有,有人会提供一个例子吗？

Answer 1

你是说这个吗？指定嵌套序列化

有一个简单的例子:

class AccountSerializer(serializers.ModelSerializer):
    class Meta:
        model = Account
        depth = 1 # You need only add this sentence.

结果是这样的:

[
  {
    "id": 1,
    "priority": 10,
    "role": {
      "id": 1,
      "department": "researcher"
    }
  }
]

但是,您可以获取ForeignKey的所有字段.我不知道如何获得ForeignKey的一些字段.

Answer 2

对于这个特殊问题,我通过在字符字段中使用source参数来表示外键而不是相关字段来解决它.在这种情况下,正确的序列化程序条目是:

geofence = serializers.CharField(source='geofence.id', read_only=True)

class Meta:
    model = Checkpoint
    fields = ('geofence', 'start_time', 'lat', 'long', 'enter_time')

我在Checkpoint表中使用了这个,因为检查点是地理围栏而不是错误地将外键放在原始帖子中的地理围栏表中.字段名称只列在类meta中.类元是必需的,因为序列化器是模型序列化器.