Question

我是DRF的新手。我有Record模型，如下所示：

class Records(models.Model):
    owner = models.ForeignKey(User, null=True)
    activity = models.ForeignKey(Activity, null=True)
    time_start = models.DateTimeField(null=True)
    time_end = models.DateTimeField(null=True)

  ...

RecordSerializer就是这个：

class RecordSerializer(serializers.ModelSerializer):

    now = datetime.today()
    owner = serializers.Field(source='owner.username')
    time_start = serializers.DateTimeField(source='now')

    class Meta:
        model = Records
        fields = ("owner", "activity", "time_start")

这就是观点：

class StartApiView(generics.CreateAPIView):
    model = Records
    serializer_class = RecordSerializer

    def pre_save(self, obj):
        obj.owner = self.request.user

POST请求是从Backbone发送的，它包含一个带有活动ID的字段，例如＆＃34; {activity：12}＆＃34;。如果我希望视图保存记录并将活动设置为ID为12的活动，我该怎么办？

Answer 1

接受的答案适用于DRF v2.x 但is no longer for newer (3.x) versions，因为它会引发此AssertionError：

AssertionError：关系字段必须提供queryset参数，或设置read_only=True。

对于较新版本，只需向其添加queryset参数：

class RecordSerializer(serializers.ModelSerializer):
    activity = serializers.PrimaryKeyRelatedField(queryset=Activity.objects.all())
    // [...]

Answer 2

Django REST Framework provides a PrimaryKeyRelatedField正好用于此用例。

class RecordSerializer(serializers.ModelSerializer):
    activity = serializers.PrimaryKeyRelatedField()
    owner = serializers.CharField(read_only=True, source='owner.username')
    time_start = serializers.DateTimeField(source='now')

    class Meta:
        model = Records
        fields = ("owner", "activity", "time_start")

这将产生类似于您要查找的输出，并且当您想要更新时，它将接受活动的id。

Django Rest Framework如何使用基于ID的相关字段保存模型

2 个答案: