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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