Django Foreign Keys connections - django

Question

I have a model Field that has a OneToMany connections with TreeSensor and WeatherStation model. Im trying to pass over the queries of each treesensor/weatherstation model that match the id of each different field but get a Field 'id' expected a number but got <built-in function id>. .How do i fix that? Maybe change something on the filter ?
class Field(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE, blank=True, null=True, default=None)
friendly_name = models.CharField(max_length=24, blank=True)
soil_type = models.CharField(max_length=24, choices=SOIL_TYPES, blank=True)
cultivation = models.CharField(max_length=128, choices=CULTIVATIONS, blank=True)
kml = models.FileField(upload_to = user_directory_path_kml, null=True, blank=True)
class TreeSensor(models.Model):
field = models.ForeignKey(Field, on_delete=models.CASCADE)
...
class WeatherStation(models.Model):
field = models.ForeignKey(Field, on_delete=models.CASCADE)
...
view
def map(request):
field_list = models.Field.objects.filter(user = request.user)
tree_sensors = models.TreeSensor.objects.filter(field__pk = id)
weather_stations = models.WeatherStation.objects.filter(field__pk = id)
context = {
"title": "Map",
"field_list": field_list,
"tree_sensors": tree_sensors,
"weather_stations" : weather_stations,
}
template = 'agriculture/map.html'
return render(request, template, context)

Answer 1

On your view you are filtering some field called field by id, which is not defined nowehere....
You have a queryset of Fields, so probably you should do something like this:
def map(request):
field_list = models.Field.objects.filter(user = request.user).values_list('id', flat=True)
tree_sensors = models.TreeSensor.objects.filter(field__id__in = field_list)
weather_stations = models.WeatherStation.objects.filter(field__id__in = field_list)

Answer 2

#Walucas your approach was correct it was kinda different though . It works out like this :
view
def map(request):
field_list = models.Field.objects.filter(user = request.user)
tree_sensors = models.TreeSensor.objects.filter(field_id__in = field_list.values_list('id',flat=True))
weather_stations = models.WeatherStation.objects.filter(field_id__in = field_list.values_list('id',flat=True))
context = {
"title": "Map",
"field_list": field_list,
"tree_sensors": tree_sensors,
"weather_stations" : weather_stations,
}
template = 'agriculture/map.html'
return render(request, template, context)