Django rest framework实现分页的示例

第一种分页PageNumberPagination

基本使用

（1）urls.py

urlpatterns = [
  re_path('(?P<version>[v1|v2]+)/page1/', Pager1View.as_view(),)  #分页1
]

（2）api/utils/serializers/pager.py

# api/utils/serializsers/pager.py
from rest_framework import serializers
from api import models

class PagerSerialiser(serializers.ModelSerializer):
  class Meta:
    model = models.Role
    fields = "__all__"

（3）views.py

from api.utils.serializsers.pager import PagerSerialiser
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination

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 = PageNumberPagination()
    #获取分页的数据
    page_roles = pg.paginate_queryset(queryset=roles,request=request,view=self)
    #对数据进行序列化
    ser = PagerSerialiser(instance=page_roles,many=True)
    return Response(ser.data)

（4）settings配置

REST_FRAMEWORK = {
  #分页
  "PAGE_SIZE":2  #每页显示多少个
}

自定义分页类

#自定义分页类
class MyPageNumberPagination(PageNumberPagination):
  #每页显示多少个
  page_size = 3
  #默认每页显示3个，可以通过传入pager1/?page=2&size=4,改变默认每页显示的个数
  page_size_query_param = "size"
  #最大页数不超过10
  max_page_size = 10
  #获取页码数的
  page_query_param = "page"


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，这里是自定义的MyPageNumberPagination
    pg = MyPageNumberPagination()
    #获取分页的数据
    page_roles = pg.paginate_queryset(queryset=roles,request=request,view=self)
    #对数据进行序列化
    ser = PagerSerialiser(instance=page_roles,many=True)
    return Response(ser.data)

第二种分页 LimitOffsetPagination

自定义

#自定义分页类2
class MyLimitOffsetPagination(LimitOffsetPagination):
  #默认显示的个数
  default_limit = 2
  #当前的位置
  offset_query_param = "offset"
  #通过limit改变默认显示的个数
  limit_query_param = "limit"
  #一页最多显示的个数
  max_limit = 10


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 = MyLimitOffsetPagination()
    #获取分页的数据
    page_roles = pg.paginate_queryset(queryset=roles,request=request,view=self)
    #对数据进行序列化
    ser = PagerSerialiser(instance=page_roles,many=True)
    return Response(ser.data)

返回的时候可以用get_paginated_response方法

自带上一页下一页

第三种分页CursorPagination

加密分页方式，只能通过点“上一页”和下一页访问数据

#自定义分页类3 (加密分页)
class MyCursorPagination(CursorPagination):
  cursor_query_param = "cursor"
  page_size = 2   #每页显示2个数据
  ordering = 'id'  #排序
  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 = MyCursorPagination()
    #获取分页的数据
    page_roles = pg.paginate_queryset(queryset=roles,request=request,view=self)
    #对数据进行序列化
    ser = PagerSerialiser(instance=page_roles,many=True)
    # return Response(ser.data)
    return pg.get_paginated_response(ser.data)

代码

版本、解析器、序列化和分页

# MyProject2/urls.py

from django.contrib import admin
from django.urls import path,include

urlpatterns = [
  #path('admin/', admin.site.urls),
  path('api/',include('api.urls') ),
]

# api/urls.py

from django.urls import path,re_path
from .views import UserView,PaserView,RolesView,UserInfoView,GroupView,UserGroupView
from .views import Pager1View

urlpatterns = [
  re_path('(?P<version>[v1|v2]+)/users/', UserView.as_view(),name = 'api_user'), #版本
  path('paser/', PaserView.as_view(),),  #解析
  re_path('(?P<version>[v1|v2]+)/roles/', RolesView.as_view()),   #序列化
  re_path('(?P<version>[v1|v2]+)/info/', UserInfoView.as_view()),  #序列化
  re_path('(?P<version>[v1|v2]+)/group/(?P<pk>\d+)/', GroupView.as_view(),name = 'gp'),  #序列化生成url
  re_path('(?P<version>[v1|v2]+)/usergroup/', UserGroupView.as_view(),),  #序列化做验证
  re_path('(?P<version>[v1|v2]+)/pager1/', Pager1View.as_view(),)  #分页1
]

# api/models.py

from django.db import models

class UserInfo(models.Model):
  USER_TYPE = (
    (1,'普通用户'),
    (2,'VIP'),
    (3,'SVIP')
  )

  user_type = models.IntegerField(choices=USER_TYPE)
  username = models.CharField(max_length=32,unique=True)
  password = models.CharField(max_length=64)
  group = models.ForeignKey('UserGroup',on_delete=models.CASCADE)
  roles = models.ManyToManyField('Role')


class UserToken(models.Model):
  user = models.OneToOneField('UserInfo',on_delete=models.CASCADE)
  token = models.CharField(max_length=64)


class UserGroup(models.Model):
  title = models.CharField(max_length=32)


class Role(models.Model):
  title = models.CharField(max_length=32)

# api/views.py
import json

from django.shortcuts import render,HttpResponse
from rest_framework.views import APIView
from rest_framework.request import Request
from rest_framework.versioning import URLPathVersioning
from . import models

##########################################版本和解析器#####################################################

class UserView(APIView):

  def get(self,request,*args,**kwargs):
    #获取版本
    print(request.version)
    #获取处理版本的对象
    print(request.versioning_scheme)
    #获取浏览器访问的url，reverse反向解析
    #需要两个参数：viewname就是url中的别名，request=request是url中要传入的参数
    #(?P<version>[v1|v2]+)/users/，这里本来需要传version的参数，但是version包含在request里面，所有只需要request=request就可以
    url_path = request.versioning_scheme.reverse(viewname='api_user',request=request)
    print(url_path)
    self.dispatch
    return HttpResponse('用户列表')

# from rest_framework.parsers import JSONParser,FormParser

class PaserView(APIView):
  '''解析'''
  # parser_classes = [JSONParser,FormParser,]
  #JSONParser：表示只能解析content-type:application/json的头
  #FormParser:表示只能解析content-type:application/x-www-form-urlencoded的头

  def post(self,request,*args,**kwargs):
    #获取解析后的结果
    print(request.data)
    return HttpResponse('paser')


###########################################序列化###########################################################

from rest_framework import serializers

#要先写一个序列化的类
class RolesSerializer(serializers.Serializer):
  #Role表里面的字段id和title序列化
  id = serializers.IntegerField()
  title = serializers.CharField()

class RolesView(APIView):
  def get(self,request,*args,**kwargs):
    # 方式一：对于[obj,obj,obj]
    # （Queryset）
    # roles = models.Role.objects.all()
    # 序列化，两个参数，instance:Queryset 如果有多个值，就需要加 mangy=True
    # ser = RolesSerializer(instance=roles,many=True)
    # 转成json格式，ensure_ascii=False表示显示中文，默认为True
    # ret = json.dumps(ser.data,ensure_ascii=False)

    # 方式二：
    role = models.Role.objects.all().first()
    ser = RolesSerializer(instance=role, many=False)
    ret = json.dumps(ser.data, ensure_ascii=False)
    return HttpResponse(ret)


# class UserInfoSerializer(serializers.Serializer):
#   '''序列化用户的信息'''
#   #user_type是choices（1,2,3），显示全称的方法用source
#   type = serializers.CharField(source="get_user_type_display")
#   username = serializers.CharField()
#   password = serializers.CharField()
#   #group.title：组的名字
#   group = serializers.CharField(source="group.title")
#   #SerializerMethodField(),表示自定义显示
#   #然后写一个自定义的方法
#   rls = serializers.SerializerMethodField()
#
#   def get_rls(self,row):
#     #获取用户所有的角色
#     role_obj_list = row.roles.all()
#     ret = []
#     #获取角色的id和名字
#     #以字典的键值对方式显示
#     for item in role_obj_list:
#       ret.append({"id":item.id,"title":item.title})
#     return ret


# class UserInfoSerializer(serializers.ModelSerializer):
#   type = serializers.CharField(source="get_user_type_display")
#   group = serializers.CharField(source="group.title")
#   rls = serializers.SerializerMethodField()
#
#   def get_rls(self, row):
#     # 获取用户所有的角色
#     role_obj_list = row.roles.all()
#     ret = []
#     # 获取角色的id和名字
#     # 以字典的键值对方式显示
#     for item in role_obj_list:
#       ret.append({"id": item.id, "title": item.title})
#     return ret
#
#   class Meta:
#     model = models.UserInfo
#     fields = ['id','username','password','type','group','rls']

# class UserInfoSerializer(serializers.ModelSerializer):
#   class Meta:
#     model = models.UserInfo
#     #fields = "__all__"
#     fields = ['id','username','password','group','roles']
#     #表示连表的深度
#     depth = 1


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 = ['id','username','password','group','roles']
    #表示连表的深度
    depth = 0


class UserInfoView(APIView):
  '''用户的信息'''
  def get(self,request,*args,**kwargs):
    users = models.UserInfo.objects.all()
    #这里必须要传参数context={'request':request}
    ser = UserInfoSerializer(instance=users,many=True,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)



####################################序列化之用户请求数据验证验证####################################

#自定义验证规则
class GroupValidation(object):
  def __init__(self,base):
    self.base = base

  def __call__(self, value):
    if not value.startswith(self.base):
      message = "标题必须以%s为开头"%self.base
      raise serializers.ValidationError(message)


class UserGroupSerializer(serializers.Serializer):
  title = serializers.CharField(validators=[GroupValidation('以我开头'),])

class UserGroupView(APIView):
  def post(self,request,*args, **kwargs):
    ser = UserGroupSerializer(data=request.data)
    if ser.is_valid():
      print(ser.validated_data['title'])
    else:
      print(ser.errors)

    return HttpResponse("用户提交数据验证")


##################################################分页###################################################

from api.utils.serializsers.pager import PagerSerialiser
from rest_framework.response import Response
from rest_framework.pagination import PageNumberPagination,LimitOffsetPagination,CursorPagination

# #自定义分页类1
# class MyPageNumberPagination(PageNumberPagination):
#   #每页显示多少个
#   page_size = 3
#   #默认每页显示3个，可以通过传入pager1/?page=2&size=4,改变默认每页显示的个数
#   page_size_query_param = "size"
#   #最大页数不超过10
#   max_page_size = 10
#   #获取页码数的
#   page_query_param = "page"

#自定义分页类2
class MyLimitOffsetPagination(LimitOffsetPagination):
  #默认显示的个数
  default_limit = 2
  #当前的位置
  offset_query_param = "offset"
  #通过limit改变默认显示的个数
  limit_query_param = "limit"
  #一页最多显示的个数
  max_limit = 10


#自定义分页类3 (加密分页)
class MyCursorPagination(CursorPagination):
  cursor_query_param = "cursor"
  page_size = 2   #每页显示2个数据
  ordering = 'id'  #排序
  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 = MyCursorPagination()
    #获取分页的数据
    page_roles = pg.paginate_queryset(queryset=roles,request=request,view=self)
    #对数据进行序列化
    ser = PagerSerialiser(instance=page_roles,many=True)
    return Response(ser.data)
    # return pg.get_paginated_response(ser.data)

# api/utils/serializsers/pager.py

from rest_framework import serializers
from api import models


class PagerSerialiser(serializers.ModelSerializer):
  class Meta:
    model = models.Role
    fields = "__all__"

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