如何根據django中的forgen鍵集進行反向查詢集

Question

它有點復雜，以下是正在執行查詢的 2 個模型：

class Line(models.Model):
    # Relationships
    end_station = models.ForeignKey("stations.station", related_name='line_end_station', on_delete=models.CASCADE)
    starting_station = models.ForeignKey("stations.station", related_name='line_start_Station',
                                         on_delete=models.CASCADE)



class InLineStation(models.Model):
    # Relationships
    line = models.ForeignKey("lines.Line", on_delete=models.CASCADE)
    in_line_station = models.ForeignKey("stations.station", on_delete=models.CASCADE)

我在請求中得到一個站點對象，我需要根據它過濾線路模型，如果它是一個開始、結束或在線站點..這是我如何嘗試的：

@api_view(['POST', ])
def do_search_logic(request):
    if request.method == 'POST':
        from_station_id = request.data['from_station_id']
        to_station_id = request.data['to_station_id']
        from_station_object = station.objects.get(id=from_station_id)
        to_station_object = station.objects.get(id=to_station_id)
        Line.objects.filter(Q(starting_station=from_station_object) | Q(end_station=to_station_object) | Q(from_station_object in inlinestations_set)) #this_is_the_tricky_line

有什么幫助嗎？？

Answer 1

試試這個查詢：

Line.objects.filter(Q(starting_station=from_station_object) | Q(end_station=to_station_object) | Q(inlinestations_set__in_line_station=from_station_object))

如果您還想包括具有to_station_object作為內聯站的線路：

Line.objects.filter(Q(starting_station=from_station_object) | Q(end_station=to_station_object) | Q(inlinestations_set__in_line_station=from_station_object) | Q(inlinestations_set__in_line_station=to_station_object))