rest framwork 4 分页功能

分页功能： 常遇到问题，当数据记录超过1000万条，如何进行分页显示问题，这时就考虑分页功能，

restframework 分页实现有三种

第一种：看n页，每页显示n条数据； PageNumberPagination,

class PagerSerializer(serializers.ModelSerializer):

    class Meta:

        model=models.Role

        fields="__all__"

class MyPageNumberPagination(PageNumberPagination):

    page_size = 2 #每页显示记录数量

    page_size_query_param = 'size'

    max_page_size = 5 #每页显示最大记录数量

    page_query_param = 'page'

第二种：记录： 在n个位置，向后查看n条数据。LimitOffsetPagination

class MyLimitOffsetPagination(LimitOffsetPagination):

    default_limit = 3

    limit_query_param = 'limit'

    offset_query_param = 'offset'

    max_limit = 5

第三种;加密分页： 上一页和下一页，记录最大值和最小值,CursorPagination

class MyCursorPagination(CursorPagination):

    cursor_query_param = 'cursor'

    page_size = 2

    ordering = '-id'

    page_size_query_param = None

    max_page_size = 4

实战使用

class PagerView(APIView):

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

        #1 获取所有数据

        roles=models.Role.objects.all()

        #2 创建分页对象

        # Pager=PageNumberPagination()

        # Pager=MyLimitOffsetPagination()

        Pager=MyCursorPagination()

        #3在数据库中获取分页的数据

        page_role=Pager.paginate_queryset(queryset=roles,request=request,view=self)

        #4对数据进行序列化

        ser = PagerSerializer(instance=page_role, many=True)

        # return Response(ser.data)

        return Pager.get_paginated_response(ser.data)

分页实战：

# coding: utf-8

from rest_framework.pagination import LimitOffsetPagination

from rest_framework.response import Response

class AuctionLimitPagination(LimitOffsetPagination):

    default_limit = 5 # 默认分页记录

    max_limit=50  # 首次分页记录

    limit_query_param = 'limit'

    offset_query_param = 'offset'

    def get_offset(self, request): #起始位置

        return 0

    def get_paginated_response(self, data): # 返回数据格式

        return Response(data)

from  rest_framework.filters import   BaseFilterBackend

class ReachBottomFilter(BaseFilterBackend):

    def filter_queryset(self, request, queryset, view):

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

        if not min_id:

            return queryset

        return queryset.filter(id__lt=min_id)

class PullDownRefreshFilter(BaseFilterBackend):

    def filter_queryset(self, request, queryset, view):

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

        if not max_id:

            return queryset

        return queryset.filter(id__gt=max_id).reverse()

from rest_framework.viewsets import GenericViewSet

from rest_framework.mixins import  RetrieveModelMixin,ListModelMixin

class auctionView(ListAPIView):

      # 如果是列表必须两个数据，一个是查询数据，一个是序列化

      queryset = models.Auction.objects.filter(status__gt=0).order_by('id')

      serializer_class = auctionSerializers

      filter_backends = [ReachBottomFilter,PullDownRefreshFilter]

      pagination_class = AuctionLimitPagination

      # #获取goods另外一种写法

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

      #     response=super(auctionView,self).get(request,*args,**kwargs)

      #     # 根据response.data获取所有专场id id_list

        #相关的所有商品    models.AuctionItem.objects.filter(auction_id_in=id_list)

            return  response

rest framwork 4 分页功能的相关教程结束。