根据下面的代码,我正在做数据库的查询,然后我正在对查询结果进行分页,所以我的问题是,如果我们在分页之前已经查询了所有数据库的结果,那有什么用呢?这是Django的分页功能,还是我装错了?我得到了预期的响应,但是在分页之前查询数据库有问题。
代码如下
class GetAllUserStoryListViewTest(APIView,LimitOffsetPagination):
permission_classes = (IsAuthenticated,)
def get_object(self,user_id):
user = User.objects.filter(id = user_id).first()
posts = Post.objects.filter(user = user)
return posts
def get(self,request,user_id):
posts = self.get_object(user_id).order_by('-post_time_stamp')
#setting the limit of this user post pagination
LimitOffsetPagination.default_limit = settings.PAGE_SIZE
posts = self.paginate_queryset(posts, request)
serializer_context = {
'request': request,
}
serializer = PostListSerializer(posts,many=True,context=serializer_context)
# return Response(serializer.data)
return self.get_paginated_response(serializer.data)
输出:
{
"count": 7,
"next": "http://127.0.0.1:8000/api/list_all_story_test/27/?limit=2&offset=5",
"previous": "http://127.0.0.1:8000/api/list_all_story_test/27/?limit=2&offset=1",
"results": [
{
"id": 15,
"file": "http://127.0.0.1:8000/media/user_27/post/IMG_20190331_144024.jpg",
"post_info": "#cool",
"post_time_stamp": "2020-05-10T10:21:10Z",
"total_comment": 2,
"liked_by": [
"vipin"
],
"user": {
"id": 27,
"username": "vipin",
"email": "[email protected]",
"status": true,
"profile": {
"id": 24,
"full_name": "Vipin",
"mobile": 6732,
"background_picture": "http://127.0.0.1:8000/media/user_27/profile/pexels-photo-531880_0qSgRNx.jpeg",
"profile_picture": "http://127.0.0.1:8000/media/user_27/profile/IMG_20190331_144024.jpg",
"BioDescription": "xyz",
"date_of_birth": "1996-06-01",
"gender": "M",
"account_type": "Private",
"user": 27
},
"last_login": null,
"is_superuser": false,
"is_staff": false,
"is_active": true,
"date_joined": "2020-04-28T11:09:27.691478Z"
},
"comment_usr": [
"xyz",
26,
"Cool Pic"
],
"like_by_you": true
},
{
"id": 13,
"file": "http://127.0.0.1:8000/media/user_30/post/IMG_20190402_102248.jpg",
"post_info": "#Awesome",
"post_time_stamp": "2020-05-10T10:20:22Z",
"total_comment": 8,
"user": {
"id": 30,
"username": "xyz",
"email": "[email protected]",
"status": false,
"profile": {
"id": 27,
"full_name": "XYZ",
"mobile": 123,
"background_picture": null,
"profile_picture": "http://127.0.0.1:8000/media/user_30/profile/demo.jpg",
"BioDescription": null,
"date_of_birth": null,
"gender": "F",
"account_type": "Private",
"user": 30
},
"last_login": null,
"is_superuser": false,
"is_staff": false,
"is_active": true,
"date_joined": "2020-04-28T11:13:58.030941Z"
},
"like_by_you": true
}
]
}
分页打数据库与 Count()
方法,到分页的结果。
而且,在每一个页面打数据库的时候,通过分片的方式,是比
使用带有 all()
方法,并且,用 Iteration
,加载所有结果。
filter()
或 all()
方法不打数据库。请看 这个 以检查何时 QuerySet
是评估。