How represent a many to many relationship with django rest framework using Hyperlinking - django-rest-framework

Question

I have two models in a 'many to many' relationship Video and Genre. I want to represent them in my API using the Django Rest Framework and with Hyperlinking. I have tried using the the nested relationships solution that I have found over the internet but it brings me an error for the list viewss eg genres/ and videos/ as described below.
models.py
class VideoGenre(models.Model):
video = models.ForeignKey(Video, on_delete=models.CASCADE, related_name='genres')
genres = models.ForeignKey(Genre, on_delete=models.CASCADE, related_name='videos')
class Meta:
unique_together = ['video', 'genre']
class Video(models.Model):
genres = models.ManyToManyField(Genre, related_name="videos", blank=True, through='VideoGenre')
title = serializers.CharField(default=serializers.CurrentUserDefault())
class Genre(models.Model):
name = models.CharField(max_length=20)
descr = models.CharField(max_length=255)
serializers.py
class GenreSerializer(serializers.HyperlinkedModelSerializer):
videos = serializers.HyperlinkedIdentityField(many=True, view_name="video-detail")
class Meta:
model = ku_api_models.Genre
fields = "__all__"
class VideoSerializer(serializers.HyperlinkedModelSerializer):
genres = GenreSerializer(source='genre_set', many=True, read_only=True)
class Meta:
model = ku_api_models.Video
fields = "__all__"
class VideoGenreSerializer(serializers.HyperlinkedModelSerializer):
video = serializers.ReadOnlyField(source='video.id')
genre = serializers.ReadOnlyField(source='genre.id')
class Meta:
model = ku_api_models.VideoGenre
fields = "__all__"
unique_together = ['video', 'genre']
views.py
class VideoDetailView(RetrieveUpdateDestroyAPIView):
parser_classes = (MultiPartParser,)
serializer_class = VideoSerializer
queryset = Video.objects.all()
def perform_update(self, serializer):
serializer.save(owner=self.request.user)
class VideoListView(ListCreateAPIView):
parser_classes = (MultiPartParser,)
serializer_class = VideoSerializer
queryset = Video.objects.all()
def perform_create(self, serializer):
serializer.save(owner=self.request.user)
class GenreListView(ListCreateAPIView):
serializer_class = GenreSerializer
queryset = Genre.objects.all()
class GenreDetailtView(RetrieveUpdateDestroyAPIView):
serializer_class = GenreSerializer
queryset = Genre.objects.all()
urls.py
path('videos/', views.VideoListView.as_view(), name='video-list'),
path('videos/<int:pk>', views.VideoDetailView.as_view(), name='video-detail'),
path('genres/', views.GenreListView.as_view(), name="genre-list"),
path('genres/<int:pk>', views.GenreDetailtView.as_view(), name="genre-detail"),
I am getting below exception on the browsable API renderer
Exception Type: ProgrammingError at /api/genres/
Exception Value: relation "ku_api_videogenre" does not exist
LINE 1: ..._video"."owner_id" FROM "ku_api_video" INNER JOIN "ku_api_vi...
I have looked into these below links as referred above
django rest framework serializing many to many field
many to many relationship through an intermidiate model
serializing many to many field
... and tried them but getting the same/almost the same, only different is the relation name that "does not exist"
What am I missing? How to make it right? Thanks

Answer 1

I have found a way to this:
Changes will be in the serializers.py
serializers.py
class VideoSerializer(serializers.HyperlinkedModelSerializer):
genres = serializers.HyperlinkedRelatedField(many=True, read_only=False, view_name='genre-detail', queryset=ku_api_models.Genre.objects.all())
class Meta:
model = ku_api_models.Video
#fields = ('url', 'id', 'datetime_added', 'title', 'video_file', 'owner')
fields = "__all__"
def create(self, validated_data):
genres = validated_data.pop('genres', [])
video_instance = ku_api_models.Video.objects.create(**validated_data)
video_instance.genres.set(genres)
return video_instance
def update(self, instance, validated_data):
genres = validated_data.pop('genres', [])
instance.genres.set(genres)
instance.save()
return instance
class VideoGenreSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = ku_api_models.VideoGenre
fields = "__all__"
class GenreSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = ku_api_models.Genre
fields = "__all__"
Source: Docs: intermediary-manytomany