Question

使用此查询：

def high_hazard(request):
    reference_high = FloodHazard.objects.filter(hazard='High')
    ids_high = reference_high.values_list('id', flat=True)

    flood_hazard = []
    djf = Django.Django(geodjango='geom', properties=['bldg_name', 'bldg_type'])
    geoj = GeoJSON.GeoJSON()
    for myid in ids_high:
        getgeom = FloodHazard.objects.get(id=myid).geom
        response_high = BuildingStructure.objects.filter(geom__intersects=getgeom)
        get_hazard = geoj.encode(djf.decode(response_high.transform(900913)))
        flood_hazard.append(get_hazard)

    return HttpResponse(flood_hazard, content_type='application/json')

我能够根据BuildingStructure类型过滤FloodHazard模型，在这种情况下使用＆＃34; high＆＃34;值。虽然它返回一个JSON数据，但输出却搞砸了。我猜是因为它在循环期间测试FloodHazard模型中的所有几何。因此，它返回几个空集或空和许多FeatureCollection，这使得它成为无效的JSON数据。上面的查询输出如下：

{
    "crs": null,
    "type": "FeatureCollection",
    "features": [

    ]
}{
    "crs": null,
    "type": "FeatureCollection",
    "features": [

    ]
}{
    "crs": null,
    "type": "FeatureCollection",
    "features": [
        {
            "geometry": {
                "type": "MultiPoint",
                "coordinates": [
                    [
                        13974390.863509608,
                        1020340.6129766875
                    ]
                ]
            },
            "type": "Feature",
            "id": 3350,
            "properties": {
                "bldg_name": "",
                "bldg_type": ""
            }
        },
        {
            "geometry": {
                "type": "MultiPoint",
                "coordinates": [
                    [
                        13974400.312472697,
                        1020356.5477410051
                    ]
                ]
            },
            "type": "Feature",
            "id": 3351,
            "properties": {
                "bldg_name": "",
                "bldg_type": ""
            }
        }
    ]
}

当我用JSON验证器测试它时，它是无效的。那么，有没有办法重构（使用underscore.js或jquery）这个JSON输出如下？或者我需要更改我的查询？

{
    "crs": null,
    "type": "FeatureCollection",
    "features": [
        {
            "geometry": {
                "type": "MultiPoint",
                "coordinates": [
                    [
                        13974390.863509608,
                        1020340.6129766875
                    ]
                ]
            },
            "type": "Feature",
            "id": 3350,
            "properties": {
                "bldg_name": "",
                "bldg_type": ""
            }
        },
        {
            "geometry": {
                "type": "MultiPoint",
                "coordinates": [
                    [
                        13974400.312472697,
                        1020356.5477410051
                    ]
                ]
            },
            "type": "Feature",
            "id": 3351,
            "properties": {
                "bldg_name": "",
                "bldg_type": ""
            }
        }
    ]
}

并忽略/删除所有没有值的FeatureCollection，并将所有值分组。 Here是上述查询的结果，仅供参考。

Answer 1

而不是

return HttpResponse(flood_hazard, content_type='application/json')

尝试

return HttpResponse(json.dumps(flood_hazard), content_type='application/json')

您必须在顶部import json。

来自Django QuerySet的JSON数据响应无效

1 个答案: