我在我的伙伴关系中遇到一个问题。 NET a. 与实体框架核心的核心应用,我一再收到以下答复:

{
  "statusCode": 500,
  "message": "The instance of entity type  Airline  cannot be tracked because another instance with the key value  {CarrierCode: DY}  is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached."
}

这发生在我<>PassengerController的“AddBaggage()”方法中的一种前方圆形:await_baggageRepository.AddAsync(NewBaggage);。 该方法:

[HttpPost("{id}/flight/{flightId}/add-baggage")]
        public async Task<ActionResult<Baggage>> AddBaggage(Guid id, int flightId,
            [FromBody] List<AddBaggageModel> addBaggageModels)
        {
            var passenger = await _passengerRepository.GetPassengerByIdAsync(id);
            var selectedFlight = await _flightRepository.GetFlightByIdAsync(flightId);
            var destination = await _destinationRepository.GetDestinationByCriteriaAsync(f =>
                f.IATAAirportCode == addBaggageModels.FirstOrDefault().FinalDestination);            

            var baggageList = new List<Baggage>();

            foreach (var baggageModel in addBaggageModels)
            {
                var newBaggage = new Baggage
                {
                    PassengerId = passenger.Id,
                    Weight = baggageModel.Weight,
                    DestinationId = destination.IATAAirportCode
                };

                //...some code
    
                else if (baggageModel.TagType == TagTypeEnum.System)
                {
                    var number = _baggageRepository.GetNextSequenceValue("BaggageTagsSequence");
                    var baggageTag = new BaggageTag(selectedFlight.ScheduledFlight.Airline, number);
                    newBaggage.BaggageTag = baggageTag;
                }

                await _baggageRepository.AddAsync(newBaggage); // An exception is thrown here, on the second iteration, when we attempt to assign a reference to the same object/instance of Airline as in the first iteration in the constructor parameter.            
                
                baggageList.Add(newBaggage);

                var orderedFlights = passenger.Flights
                    .Where(f => f.Flight.DepartureDateTime >= selectedFlight.DepartureDateTime)
                    .OrderBy(f => f.Flight.DepartureDateTime)
                    .ToList();

                foreach (var connectingFlight in orderedFlights)
                {
                    //...some code

                    FlightBaggage flightBaggage = new FlightBaggage
                    {
                        Flight = connectingFlight.Flight,
                        Baggage = newBaggage,
                        BaggageType = baggageType
                    };

                    newBaggage.Flights.Add(flightBaggage);

                    //...some code
                }
            }

            await _baggageRepository.UpdateAsync(baggageList.ToArray());

            return Ok();
        }

这里也是BagageTag建筑商之一:

        public BaggageTag(Airline? airline, int number)
        {
            Airline = airline;
            LeadingDigit = 0;
            Number = number;
            TagNumber = _GetBaggageTagNumber();
            TagType = TagTypeEnum.System;
        }

我在上还有以下法典。 页: 1

        public async Task<Flight> GetFlightByIdAsync(int id)
        {
            var CACHE_KEY = $"Flight_{id}";

            if (!_cache.TryGetValue(CACHE_KEY, out Flight flight))
            {
                flight = await _context.Flights.AsNoTracking()
                .Include(_ => _.ScheduledFlight)
                    .ThenInclude(_ => _.DestinationFrom)
                .Include(_ => _.ScheduledFlight)
                    .ThenInclude(_ => _.DestinationTo)
                .Include(_ => _.ScheduledFlight)
                    .ThenInclude(_ => _.Airline)
                .Include(_ => _.Aircraft)
                    .ThenInclude(_ => _.AircraftType)
                .Include(_ => _.Boarding)
                .Include(_ => _.ListOfBookedPassengers)
                    .ThenInclude(_ => _.Passenger)
                .Include(_ => _.ListOfCheckedBaggage)
                    .ThenInclude(_ => _.Baggage)
                .Include(_ => _.Seats)
                .FirstOrDefaultAsync(_ => _.Id == id);

                if (flight != null)
                {
                    _cache.Set(CACHE_KEY, flight, new MemoryCacheEntryOptions
                    {
                        SlidingExpiration = TimeSpan.FromMinutes(10)
                    });
                }
            }

            return flight;
        }

        public async Task<Passenger> GetPassengerByIdAsync(Guid id)
        {
            return await _context.Passengers.AsNoTracking()
                .Include(_ => _.PNR)
                .Include(_ => _.FrequentFlyer)
                .Include(_ => _.TravelDocuments)
                .Include(_ => _.PassengerCheckedBags)
                    .ThenInclude(_ => _.BaggageTag)
                .Include(_ => _.PassengerCheckedBags)
                    .ThenInclude(_ => _.SpecialBag)
                .Include(_ => _.Flights)
                    .ThenInclude(_ => _.Flight)
                        .ThenInclude(_ => _.ScheduledFlight)
                            .ThenInclude(_ => _.Airline)
                .Include(_ => _.Comments)
                    .ThenInclude(_ => _.PredefinedComment)
                .Include(_ => _.AssignedSeats)
                .Include(_ => _.SpecialServiceRequests)
                    .ThenInclude(_ => _.SSRCode)
                .FirstOrDefaultAsync(_ => _.Id == id);
        }