Question

我试图得到一个Json响应，其中包含地理位置和Django中外键对象的信息。

我当前的代码如下：

    location_point = Point(location.longitude, location.latitude, srid=4326)
    events = TimetableEvent.objects.annotate(distance=Distance('venue__location', location_point)).order_by('distance')[0:5].values('activity__name','venue__name','venue__location','distance')
    qs_json = serializers.serialize('geojson', events,geometry_field='point')

这在尝试使用值查询集时给了我一个元错误

*** AttributeError: 'dict' object has no attribute '_meta'

我也尝试过使用geojson字段选择点，但是我没有运气：

        location_point = Point(location.longitude, location.latitude, srid=4326)
    events = TimetableEvent.objects.annotate(distance=Distance('venue__location', location_point)).order_by('distance')[0:5]
    qs_json = serializers.serialize('geojson', events,geometry_field='venue__location',fields=('activity__name','venue__name','venue__location','distance',))

这只是给我空数据

    p qs_json
'{"type": "FeatureCollection", "crs": {"type": "name", "properties": {"name": "EPSG:4326"}}, "features": [{"type": "Feature", "properties": {}, "geometry": null}, {"type": "Feature", "properties": {}, "geometry": null}, {"type": "Feature", "properties": {}, "geometry": null}, {"type": "Feature", "properties": {}, "geometry": null}]}'

然后我尝试使用json转储打印出数据列表，但出现与距离注释或点有关的错误，例如：

(Pdb) json.dumps(list(events))
*** TypeError: Object of type 'Point' is not JSON serializable

有几种方法可以做到，但是我真的很感谢能以正确的方式获得帮助！

时间表事件的模型是：

class TimetableEvent(models.Model):
    activity = models.ForeignKey(Activity, on_delete=models.DO_NOTHING,) 
    venue = models.ForeignKey(Venue,on_delete=models.DO_NOTHING,)
    start_time = models.TimeField()
    end_time =models.TimeField()
    date = models.DateTimeField('event date')
    def __str__(self):
        return self.activity.name +' at '+ self.venue.name

Json序列化GeoDjago点以及FK关系

0 个答案: