Django对postgresql数据库进行分组聚合查询

action(methods=['GET'], detail=False, url_path='count')

def count(self, request):

    """统计最近30天的抓拍记录"""

    starttime = request.query_params.get('starttime')

    endtime = request.query_params.get('endtime')

    days = datetime.timedelta(days=1)

    start_date = datetime.datetime.strptime(starttime, '%Y%m%d%H%M%S').date()

    end_date = datetime.datetime.strptime(endtime, '%Y%m%d%H%M%S').date()

    count_list = {

        'dates': {

            'start_date': start_date,

            'end_date': end_date

        },

        'result': []

    }

    if end_date - start_date == days:

        result_list = models.DevicePhotoModel.objects.filter(take_photo_time__range=(start_date, end_date))\

            .extra(select={"take_photo_time": "to_char(take_photo_time, 'HH')"}).values('take_photo_time') \

            .annotate(count=Count('take_photo_time')).values('take_photo_time', 'count')

        # 统计当天的数据

    else:

        result_list = models.DevicePhotoModel.objects.filter(take_photo_time__range=(start_date, end_date)) \

            .extra(select={"take_photo_time": "to_char(take_photo_time, 'yyyy-mm-dd')"}).values('take_photo_time') \

            .annotate(count=Count('take_photo_time')).values('take_photo_time', 'count')

    for result in result_list:

        count_list['result'].append({

            'date': result['take_photo_time'],

            'count': result['count']

        })

    return Response(count

mysql和postgres数据库格式化方法不同。网上找了很多格式化案例，但是都会报错。mysql中用DATE_FORMAT格式化，postgresql中用TO_CHAR格式化，格式化参数也有些许差别

Django对postgresql数据库进行分组聚合查询的相关教程结束。