Solution #664
Solution #664
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| class Meta: | ||
| model = Actor | ||
| fields = ("id", "first_name", "last_name", "full_name") | ||
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| def get_full_name(self, obj): |
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You also can wrote property for Actor method
cinema/serializers.py
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| ) | ||
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| def get_tickets_available(self, movie_session): |
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You also can calculate it in view
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This is inefficient because we will have to query database for tickets.count() on every entry in a list. Better to override queryset and use annotate()
cinema/serializers.py
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| for ticket_data in tickets_data: | ||
| Ticket.objects.create(order=order, **ticket_data) | ||
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| return order |
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On create/update/delete functions you don't need to return anything
cinema/views.py
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| @@ -31,28 +46,90 @@ class CinemaHallViewSet(viewsets.ModelViewSet): | |||
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| class MovieViewSet(viewsets.ModelViewSet): | |||
| queryset = Movie.objects.all() | |||
| queryset = Movie.objects.prefetch_related("genres", "actors").all() | |||
| return super().get_serializer_class() | ||
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| def get_queryset(self): | ||
| queryset = self.queryset |
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call super method instead of accesing this attribute directly
solve N+1 problem
cinema/views.py
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| return super().get_serializer_class() | ||
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| def get_queryset(self): | ||
| queryset = self.queryset.annotate( |
cinema/serializers.py
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| ) | ||
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| def get_tickets_available(self, movie_session): |
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This is inefficient because we will have to query database for tickets.count() on every entry in a list. Better to override queryset and use annotate()
cinema/serializers.py
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| movie = MovieListSerializer(read_only=True) | ||
| cinema_hall = CinemaHallSerializer(read_only=True) | ||
| taken_places = serializers.SerializerMethodField() | ||
| tickets_available = serializers.SerializerMethodField() |
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this should be shown only on List serializer
cinema/serializers.py
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| class MovieSessionDetailSerializer(serializers.ModelSerializer): | ||
| movie = MovieListSerializer(read_only=True) | ||
| cinema_hall = CinemaHallSerializer(read_only=True) | ||
| taken_places = serializers.SerializerMethodField() |
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You can use nested serializer here instead - create TicketSeatsSerializer with row / seat fields and pass it to taken_places. then you will not need a separate method get_taken_places
cinema/serializers.py
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| class OrderCreateSerializer(serializers.ModelSerializer): | ||
| tickets = serializers.ListField() |
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instead create a modified version of ticket serializer without movie_session = MovieSessionListSerializer(read_only=True) and pass it here
cinema/views.py
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| return super().get_serializer_class() | ||
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| def get_queryset(self): | ||
| queryset = super().get_queryset() |
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is better to access queryset like so : self.queryset
cinema/views.py
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| def get_queryset(self): | ||
| queryset = super().get_queryset() | ||
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| genres_param = self.request.query_params.get("genres") |
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all of this can go under if condition
cinema/views.py
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| queryset = MovieSession.objects.all() | ||
| queryset = ( | ||
| MovieSession.objects.select_related | ||
| ("movie", "cinema_hall").prefetch_related("tickets").all() |
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you don't need to prefetch tickets on every action and you don't need all() in the end
cinema/views.py
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| return queryset.distinct() | ||
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| class OrderPagination(PageNumberPagination): |
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would be better to put pagination in separate file
cinema/views.py
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| Order.objects.prefetch_related | ||
| ("tickets__movie_session__movie", | ||
| "tickets__movie_session__cinema_hall" | ||
| ).all() |
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no need for all() if you already used prefetch
cinema/views.py
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| queryset = super().get_queryset().annotate( | ||
| available_tickets=F("cinema_hall__rows") | ||
| * F("cinema_hall__seats_in_row") - Count("tickets") | ||
| ) |
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