Django不威胁例外

Question

你能帮帮我吗？Django不威胁例外情况。当发生这种情况时，我希望它返回完整性异常块。但是没有，它继续到the块，这就引发了完整性异常。我尝试过使用“从django.db.utils导入IntegrityError”和“从django.db导入IntegrityError”

        datafile = csv.DictReader(datafile, delimiter=',')
        roadnetwork = RoadNetwork.objects.get(id=pk)
                                  
        for row in datafile:
            row = {k: None if not v else v for k, v in row.items()}

            try:
                road_type_id = row['id']
                name = row['name']
                roadtype = RoadType(
                    road_type_id=road_type_id,
                    name=name,
                    congestion=CONGESTION_TYPES[row['congestion'].lower()],
                    default_speed=row.get('default_speed', None),
                    default_lanes=row.get('default_lanes', None),
                    default_param1=row.get('default_param1', None),
                    default_param2=row.get('default_param2', None),
                    default_param3=row.get('default_param3', None),
                    color=row.get('color', None))
                 
            except IntegrityError:
                e = 'this data already exists in the database'
                
                return render(request, template,  context={'e': e})

            else:
                roadtype = RoadType(
                    road_type_id=road_type_id,
                    name=name,
                    congestion=CONGESTION_TYPES[row['congestion'].lower()],
                    default_speed=row.get('default_speed', None),
                    default_lanes=row.get('default_lanes', None),
                    default_param1=row.get('default_param1', None),
                    default_param2=row.get('default_param2', None),
                    default_param3=row.get('default_param3', None),
                    color=row.get('color', None),
                    network=roadnetwork)

Answer 1

您需要将该项提交到数据库：

try:
    roadtype = RoadType.objects.create(
        ...
    )
except IntegrityError:
    ...
else:
    ...

目前，这将创建对象，但不会将其保存到数据库中，因此无法获得IntegrityError。