活动是游客信息,标签(首选项)是标签信息(例如Instagram哈希标签)。
Activity ListPreference api的功能:对于每个活动,请检查每个活动是否包含请求列表中的标签。只有包含标签的活动才被序列化。
但是速度太慢。大约需要1分钟。
返回所有活动的api只需要2秒。
怎么了?
class ActivityListByPreference(APIView):
permission_classes = (permissions.AllowAny,)
def get(self, request):
request_tag = [6, 7, 8]
activity_list = []
activity_items = Activity.objects.filter()
activity_nums=activity_items.values_list('num', flat=True)
b=1
for activity_num in activity_nums:
print(activity_num)
activity_preference_items = Activity_Preference.objects.filter(activity_num_id=activity_num)
activity_tag = []
preference_nums= activity_preference_items.values_list('preference_num_id',flat=True)
activity_tag=list(preference_nums)
intersection = set([])
intersection = set(request_tag).intersection(set(activity_tag))
inter_list = list(intersection)
inter_list.sort()
if (request_tag == inter_list):
print('포함합니다.')
activity_list.append(activity_num)
activity_preference_items = Activity_Preference.objects.all()
for activity_preference_item in activity_preference_items:
activity_tag.append(activity_preference_item.preference_num_id)
print('끝')
data = Activity.objects.filter(pk__in=activity_list)
serializer = ActivitySerializer(data, many=True)
print(data)
return Response({"ActivityListByPreference" : serializer.data})
正如所写,Python正在单独进行数据库查询,以获取数据库中每个activity_preference_items
的activity_num
。然后将结果用于在Python中执行过滤。
为了加快速度,您需要使用较少的数据库查询来执行更多的过滤。
例如,.filter()
在Django中是懒惰的,因此您可以链接多个过滤器,并且Django最后仍将只运行一个数据库查询。它可以包含lookups that span relationships,因此根据您的型号,您将获得类似以下内容的代码:
def get(self, request):
request_tag = [6, 7, 8]
activity_items = Activity.objects.filter()
for request_tag_item in request_tag:
activity_items = activity_items.filter(preference=request_tag_item)
data = activity_items
serializer = ActivitySerializer(data, many=True)