.分页

    a. 分页 看第n页 每页显示n条数据:

    b. 分页 在某个位置 向后查看多少条数据

    c. 加密分页 上一页和下一页

    本质：查看 记住页码id的最大值和最小值 通过其来准确扫描

    过去的话 会从id 1到n扫描

    第一种分页

api下的utils.serializers.pager.py

from rest_framework import serializers

from api import models

class PagerSerialiser(serializers.ModelSerializer):

    class Meta:

        model = models.Role

        fields = "__all__"

url里写

from django.contrib import admin

from api import views

from django.conf.urls import url

urlpatterns = [

    url(r'^pager1/', views.Pager1View.as_view())

]

视图里写

from rest_framework.response import Response

from api.utils.serializers.pager import PagerSerialiser

from rest_framework.pagination import PageNumberPagination

class MyPageNumberPagination(PageNumberPagination):

    page_size=  #默认两个

    page_size_query_param = 'size'  #传一个size参数 一页显示多少  http://127.0.0.1:8000/pager1/?page=1&size=3

    max_page_size =   #一页显示最大5个

    page_query_param = 'page'  #页码

class Pager1View(APIView):

    def get(self,request, *args,**kwargs):

        #获取所有数据

        roles = models.Role.objects.all()

        #创建分页对象

        pg = MyPageNumberPagination()

        #在数据库中获取分页数据

        pager_roles = pg.paginate_queryset(queryset=roles, request=request,view=self)

        print(pager_roles)

        #对分页数据进行序列化

        ser = PagerSerialiser(instance=pager_roles, many=True)

        return pg.get_paginated_response(ser.data)  #返回上一页或者下一页

第二种分页 索引值最大最小值分页

视图函数

from django.shortcuts import render,HttpResponse

import json

# Create your views here.

from rest_framework.views import APIView

from rest_framework import serializers

from api import models

class UserInfoserializer(serializers.ModelSerializer):

    group = serializers.HyperlinkedIdentityField(view_name='gp',lookup_field='group_id',lookup_url_kwarg='pk')

    class Meta:

        model = models.UserInfo

        # fields = '__all__'

        fields = ['group']

        depth =  #0到3 4层

class UserInfoView(APIView):

    def get(self,request, *arg, **kwargs):

        users = models.UserInfo.objects.all()

        ser = UserInfoserializer(instance=users, many=True,context={'request': request})  #必须添加 context = {'request':request}

        ret = json.dumps(ser.data, ensure_ascii = False)

        return HttpResponse(ret)

class GroupSerializer(serializers.ModelSerializer):

    class Meta:

        model = models.UserGroup

        fields = '__all__'

class GroupView(APIView):

    def get(self,request,*args,**kwargs):

        pk = kwargs.get('pk')

        obj = models.UserGroup.objects.filter(pk=pk).first()

        ser = GroupSerializer(instance=obj, many=False)

        ret = json.dumps(ser.data,ensure_ascii=False)

        return HttpResponse(ret)

from rest_framework.response import Response

from api.utils.serializers.pager import PagerSerialiser

from rest_framework.pagination import PageNumberPagination,LimitOffsetPagination

class MyPageNumberPagination(PageNumberPagination):

    page_size=  #默认两个

    page_size_query_param = 'size'  #传一个size参数 一页显示多少  http://127.0.0.1:8000/pager1/?page=1&size=3

    max_page_size =   #一页显示最大5个

    page_query_param = 'page'  #页码

class MyPagenumber2Pagination(LimitOffsetPagination):

    default_limit =

    limit_query_param = 'limit'  #每页多少条数据

    offset_query_param = 'offset'  #第几个索引开始

    max_limit = 

class Pager1View(APIView):

    def get(self,request, *args,**kwargs):

        #获取所有数据

        roles = models.Role.objects.all()

        #创建分页对象

        pg = MyPagenumber2Pagination()

        #在数据库中获取分页数据

        pager_roles = pg.paginate_queryset(queryset=roles, request=request,view=self)

        print(pager_roles)

        #对分页数据进行序列化

        ser = PagerSerialiser(instance=pager_roles, many=True)

        # return pg.get_paginated_response(ser.data)  #返回上一页或者下一页

        return Response(ser.data)

    分页第三种：cursion

from rest_framework.response import Response

from api.utils.serializers.pager import PagerSerialiser

from rest_framework.pagination import PageNumberPagination,LimitOffsetPagination,CursorPagination

class MyPageNumberPagination(PageNumberPagination):

    page_size=  #默认两个

    page_size_query_param = 'size'  #传一个size参数 一页显示多少  http://127.0.0.1:8000/pager1/?page=1&size=3

    max_page_size =   #一页显示最大5个

    page_query_param = 'page'  #页码

class MyPagenumber2Pagination(LimitOffsetPagination):

    default_limit =

    limit_query_param = 'limit'  #每页多少条数据

    offset_query_param = 'offset'  #第几个索引开始

    max_limit = 

class MyPagenumber3Pagination(CursorPagination):

    cursor_query_param = 'cursor'

    page_size =

    ordering = 'id'

    page_size_query_param = None

    max_page_size = None

class Pager1View(APIView):

    def get(self,request, *args,**kwargs):

        #获取所有数据

        roles = models.Role.objects.all()

        #创建分页对象

        pg = MyPagenumber3Pagination()

        #在数据库中获取分页数据

        pager_roles = pg.paginate_queryset(queryset=roles, request=request,view=self)

        print(pager_roles)

        #对分页数据进行序列化

        ser = PagerSerialiser(instance=pager_roles, many=True)

        return pg.get_paginated_response(ser.data)  #返回上一页或者下一页