解决大数据分页的效率问题：
- 记录当前访问页的数据ID，在发送下一页的访问请求时，SQL语句中进行约束（id>page_size*page_num）
- 最多显示120页（参考抽屉新热榜）
- 只显示上一页下一页按钮，对页码加密
django-restframework中有三种分页类：
-
LimitOffsetPagination——基于offest+limit
-
PageNumberPagination——基于页码
-
CursorPagination——基于cursor
class LimitOffsetPagination(BasePagination):
default_limit = api_settings.PAGE_SIZE # 默认每页显示多少条
limit_query_param = 'limit' # 获取请求中每页显示条数时的key
offset_query_param = 'offset' # 偏移量的key
max_limit = None # 客户端每页最大请求条数
class PageNumberPagination(BasePagination):
page_size = api_settings.PAGE_SIZE # 默认每页显示多少条，默认为None，表示禁用分页
page_query_param = 'page' # 获取页数时的key
page_size_query_param = None # 客户端请求时，每页条数的key，可以设置为'page_size'
max_page_size = None # 客户端每页最大请求条数
last_page_strings = ('last',)
class CursorPagination(BasePagination):
cursor_query_param = 'cursor'
page_size = api_settings.PAGE_SIZE # 每页几条
ordering = '-created' # 排序
page_size_query_param = None # 客户端请求时，每页条数的key，可以设置为'page_size'
max_page_size = None # 最大请求到多少页
offset_cutoff = 1000
使用
1.根据页码进行分页
urls.py
from django.conf.urls import url, include
from rest_framework import routers
from web.views import s9_pagination
urlpatterns = [
url(r'^test/', s9_pagination.UserViewSet.as_view()),
]
views.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework import serializers
from .. import models
from rest_framework.pagination import PageNumberPagination
class StandardResultsSetPagination(PageNumberPagination):
# 默认每页显示的数据条数
page_size = 1
# 获取URL参数中设置的每页显示数据条数
page_size_query_param = 'page_size'
# 获取URL参数中传入的页码key
page_query_param = 'page'
# 最大支持的每页显示的数据条数
max_page_size = 1
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = models.UserInfo
fields = "__all__"
class UserViewSet(APIView):
def get(self, request, *args, **kwargs):
user_list = models.UserInfo.objects.all().order_by('-id')
# 实例化分页对象，获取数据库中的分页数据
paginator = StandardResultsSetPagination()
page_user_list = paginator.paginate_queryset(user_list, self.request, view=self)
# 序列化对象
serializer = UserSerializer(page_user_list, many=True)
# 生成分页和数据
response = paginator.get_paginated_response(serializer.data)
return response
2.根据位置和个数进行分页
urls.py
from django.conf.urls import url, include
from web.views import s9_pagination
urlpatterns = [
url(r'^test/', s9_pagination.UserViewSet.as_view()),
]
views.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework import serializers
from .. import models
from rest_framework.pagination import PageNumberPagination,LimitOffsetPagination
class StandardResultsSetPagination(LimitOffsetPagination):
# 默认每页显示的数据条数
default_limit = 10
# URL中传入的显示数据条数的参数
limit_query_param = 'limit'
# URL中传入的数据位置的参数
offset_query_param = 'offset'
# 最大每页显得条数
max_limit = None
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = models.UserInfo
fields = "__all__"
class UserViewSet(APIView):
def get(self, request, *args, **kwargs):
user_list = models.UserInfo.objects.all().order_by('-id')
# 实例化分页对象，获取数据库中的分页数据
paginator = StandardResultsSetPagination()
page_user_list = paginator.paginate_queryset(user_list, self.request, view=self)
# 序列化对象
serializer = UserSerializer(page_user_list, many=True)
# 生成分页和数据
response = paginator.get_paginated_response(serializer.data)
return response
3.游标分页
urls.py
from django.conf.urls import url, include
from web.views import s9_pagination
urlpatterns = [
url(r'^test/', s9_pagination.UserViewSet.as_view()),
]
views.py
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from rest_framework.views import APIView
from rest_framework import serializers
from .. import models
from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination
class StandardResultsSetPagination(CursorPagination):
# URL传入的游标参数
cursor_query_param = 'cursor'
# 默认每页显示的数据条数
page_size = 2
# URL传入的每页显示条数的参数
page_size_query_param = 'page_size'
# 每页显示数据最大条数
max_page_size = 1000
# 根据ID从大到小排列
ordering = "id"
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = models.UserInfo
fields = "__all__"
class UserViewSet(APIView):
def get(self, request, *args, **kwargs):
user_list = models.UserInfo.objects.all().order_by('-id')
# 实例化分页对象，获取数据库中的分页数据
paginator = StandardResultsSetPagination()
page_user_list = paginator.paginate_queryset(user_list, self.request, view=self)
# 序列化对象
serializer = UserSerializer(page_user_list, many=True)
# 生成分页和数据
response = paginator.get_paginated_response(serializer.data)
return response
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