Python 在Django GeoJSON序列化程序中包含外键

当我用geojson序列化一个对象时，我需要添加一个包含反向外键的字段

我使用Django 1.9，并具有以下模型：

class NaturalEarthProvince(models.Model):
    adm1_code = models.CharField(max_length=10, primary_key=True)
    name = models.CharField(max_length=100)
    geom = models.MultiPolygonField(srid=4326)
    objects = models.GeoManager()

class NaturalEarthMerged(models.Model):
    basicname = models.CharField(max_length=200, blank=True)
    fkprovince = models.OneToOneField(NaturalEarthProvince, blank=True, null=True)
    fktouristicarea = models.ForeignKey(TouristicArea, blank=True, null=True, related_name='relatednatmerged', on_delete=models.SET_NULL)

class TouristicArea(models.Model):
    areaname = models.CharField(max_length=200, blank=True)
    fkcountry = models.ForeignKey(NaturalEarthCountry, blank=True, null=True)

我想做的是：

location = NaturalEarthProvince.objects.filter(adm0_a3=code)
locationserialized = serialize('geojson', location, geometry_field='geom', fields=('name', 'adm1_cod_1', 'touristicarea')

旅游区为location.naturalearthmerged.fk旅游区

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有什么线索吗？

我解决这个问题的唯一方法是将这个特定字段手动添加到json对象中：

locationserialized = serialize('geojson', location, geometry_field='geom', fields=('name', 'adm1_cod_1', 'adm0_a3'))
resp_obj = json.loads(locationserialized)
i = 0
for eachobj in resp_obj['features']:
    try:
        resp_obj['features'][i]['properties']['touristicarea'] = NaturalEarthMerged.objects.filter(fkprovince__adm1_cod_1=eachobj['properties']['adm1_cod_1'])[0].fktouristicarea.id
    except:
        resp_obj['features'][i]['properties']['touristicarea'] = 0
i = i+1
return JsonResponse(resp_obj)