Django Rest框架关系序列化

Question

我试图用外键获取以下模型的序列化数据，但在输出中，我只获取i，而不是与超链接相关的模型字段。

我试过使用配置文件序列化程序中的注释行获取技能模型的所有字段，但没有成功。

models.py

class Profile(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    first_name = models.CharField(max_length=20, null=True)
    last_name = models.CharField(max_length=20, null=True)

    def __str__(self):
        return 'Profile for user {}'.format(self.user.username)


class Skill(models.Model):
    skill = models.CharField(max_length=20, null=True)
    level = models.CharField(max_length=20, null=True)
    user = models.ForeignKey(Profile, null=True,
                             on_delete=models.PROTECT, related_name='skills')

    def __str__(self):
        return '%s: %s: %s' % (self.user, self.skill, self.level)

serializer.py

class SkillSerializer(serializers.ModelSerializer):

    class Meta:
        model = Skill
        fields = ('user', 'skill', 'level')

class ProfileSerializer(serializers.ModelSerializer):

    class Meta:
        # skills = SkillSerializer(many=True, read_only=True)  # serializes child model's data inside this model's data
        # skills = serializers.HyperlinkedRelatedField(many=True, read_only=True, view_name='skill-detail')
        # skills = serializers.StringRelatedField(many=True)
        # skills = serializers.HyperlinkedIdentityField( view_name = "skill-list", lookup_field = "user")
        url = HyperlinkedIdentityField( view_name="profile-detail", lookup_field = "id")
        # user = serializers.ReadOnlyField(source='user.username')
        # pdb.set_trace()

        model = Profile
        fields = ['id', 'user', 'url', 'skills']

views.py

class ProfileList(generics.ListCreateAPIView):
    queryset = Profile.objects.all()
    serializer_class = ProfileSerializer

class ProfileDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Profile.objects.all()
    serializer_class = ProfileSerializer

class SkillList(generics.ListCreateAPIView):
    queryset = Skill.objects.all()
    serializer_class = SkillSerializer

class SkillDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Skill.objects.all()
    serializer_class = SkillSerializer

urls.py

path('profiles/', views.ProfileList.as_view(), name='profile-list'),
path('profiles/<int:pk>/', views.ProfileDetail.as_view(), name='profile-detail'),   
path('skills/', views.SkillList.as_view(), name='profile-list'),
path('skills/<int:pk>/', views.SkillDetail.as_view(), name='skill-list'),

输出：http://127.0.0.1:8000/authenticator/profiles/

   [  "id": 6,
        "user": 4,
        "url": "http://127.0.0.1:8000/authenticator/profiles/6/",
        "skills": [
            57,
            55
        ],
   ]

预期产出：

   [  "id": 6,
        "user": 4,
        "url": "http://127.0.0.1:8000/authenticator/profiles/6/",
        "skills": [
              {
                "user": 6,
                "skill": "ABC",
                "level": "Beginner"
              },
              {
                "user": 6,
                "skill": "DEF",
                "level": "Intermediate"
              },
         ]
    ]

Answer 1

这通常适用于serializer.py中的以下内容：

class ProfileSerializer(serializers.ModelSerializer):
    skills = SkillSerializer(many=True, read_only=True)  # serializes child model's data inside this model's data
    url = HyperlinkedIdentityField( view_name="profile-detail", lookup_field = "id")

    class Meta:
        model = Profile
        fields = ['id', 'user', 'url', 'skills']

因此，基本上取消ProfileSerializer被告知使用SkillsSerializers序列化技能的行，这样整个技能对象都包含在结果中，而不是in中。

Answer 2

您可以为解决方案使用嵌套序列化器的概念。

创建两个序列化程序ProfileReadSerializer和ProfileWriteSerializer

serializers.py

class SkillSerializer(serializers.ModelSerializer):
    class Meta:
        model = Skill
        fields = ('user', 'skill', 'level')


class ProfileReadSerializer(serializers.ModelSerializer):
    skills = SkillSerializer(many=True, read_only=True)
    url = HyperlinkedIdentityField( view_name="profile-detail", lookup_field = "id")

    class Meta:
        model = Profile
        fields = ('id', 'user', 'url', 'skills')


class ProfileWriteSerializer(serializers.ModelSerializer):
    skills = SkillSerializer(many=True)

    class Meta:
        model = Profile
        fields = ('id', 'user', 'url', 'skills')

在视图中，您可以简单地使用ModelViewSet使事情变得简单，并使用get_serializer_class

views.py

from rest_framework.viewsets import ModelViewSet

class ProfileVewSet(ModelViewSet):
    queryset = Profile.objects.all()

    def get_serializer_class(self):
        if self.request.method == 'POST' or self.request.method == 'PUT' or self.request.method == 'PATCH':
            return ProfileWriteSerializer
        else:
            return ProfileReadSerializer

最后，如果您正在使用ModelViewSet，则需要更改urls.py

urls.py

from rest_framework.routers import DefaultRouter

router = DefaultRouter()
router.register('profile', views.ProfileViewSet, base_name='profile')

urlpatterns = [
    path('', include(router.urls))
]

我想这能解决你的问题。请看一下。