PageNumberPagination、LimitOffsetPagination、CursorPagination

数据

from django.db import modelsclass User(models.Model):username = models.CharField(max_length=64, verbose_name='用户名')password = models.CharField(max_length=64, verbose_name='密码')# 用户类型user_type = models.IntegerField(choices=((1, '菜鸟用户'), (2, '普通用户'), (3, '超级用户')), verbose_name='用户级别')# 一对一的关系，关联字段写好之后，要考虑谁拿谁的情况多，最好将用的多的放外键
class UserToken(models.Model):token = models.CharField(max_length=64, verbose_name='随机字符串')user = models.OneToOneField(to=User, on_delete=models.CASCADE)# 也等于# user = models.ForeignKey(to=User, unique=True, on_delete=models.CASCADE)class Book(models.Model):title = models.CharField(max_length=32, verbose_name='书名')price = models.IntegerField(verbose_name='书价')publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE)users = models.ManyToManyField(to=User)def publish_detail(self):return {'name': self.publish.name, 'addr': self.publish.addr}def user_list(self):lst = []for user in self.users.all():lst.append({'username': user.username,'password': user.password,'user_type': user.get_user_type_display()})class Publish(models.Model):name = models.CharField(max_length=32, verbose_name='出版社名称')addr = models.CharField(max_length=32, verbose_name='出版社地址')

路由

from django.contrib import admin
from django.urls import path, include
from rest_framework.routers import DefaultRouter, SimpleRouterfrom app01.views import BookViewrouter = SimpleRouter()
router.register('books', BookView, 'books')urlpatterns = [path('admin/', admin.site.urls),path('', include(router.urls))
]

序列化类

from rest_framework import serializers
from rest_framework.exceptions import ValidationError
from .models import User, UserToken, Book, Publishclass UserSerializer(serializers.ModelSerializer):class Meta:model = Userfields = '__all__'class PublishSerializer(serializers.ModelSerializer):class Meta:model = Publishfields = '__all__'class BookSerializer(serializers.ModelSerializer):class Meta:model = Bookfields = ['title', 'price', 'publish', 'users', 'publish_detail', 'user_list']extra_kwargs = {'publish': {'write_only': True},'users': {'write_only': True},}publish_detail = serializers.DictField(read_only=True)user_list = serializers.ListField(read_only=True)def validate_users(self, value):if len(value) > 5:raise ValidationError('一本图书的作者最多5个')return valuedef validate(self, attrs):title = attrs.get('title')publish = attrs.get('publish')# 检查 title 和 publish 是否包含敏感信息sensitive_words = ['SB', 'DJB', 'CNM']for word in sensitive_words:if word in title:raise ValidationError('标题包含敏感信息')if word in publish:raise ValidationError('出版社名称包含敏感信息')return attrs

分页 page.py

from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination# 继承PageNumberPagination分页
class CommonPageNumberPagination(PageNumberPagination):# 过滤形式# http://api.example.org/accounts/?page=4# http://api.example.org/accounts/?page=4&page_size=100# 需要重写几个类属性page_size = 3  # 每页显示2条page_query_param = 'page'  # 指定第几页的 key 值page_size_query_param = 'size'  # 指定每页显示多少条max_page_size = 5  # 每页最多显示5条# 继承LimitOffsetPagination分页
class CommonLimitOffsetPagination(LimitOffsetPagination):# 过滤形式# http://api.example.org/accounts/?limit=3  从开始取3条# http://api.example.org/accounts/?offset=4&limit=5  从第4条开始取5条default_limit = 2  # 默认每页显示3条limit_query_param = 'limit'  # 每页显示多少条的查询条件offset_query_param = 'offset'max_limit = 5# 继承CursorPagination分页
class CommonCursorPagination(CursorPagination):# 只能上一条和下一条，不能指定跳转到中间的某页----》效率高，大数据cursor_query_param = 'cursor'  # 查询条件，用不到，需要有page_size = 2  # 每页显示2条ordering = 'id'  # 按id排序

视图函数

PageNumberPagination

from rest_framework.generics import GenericAPIView
from rest_framework.response import Responsefrom .models import Book
from .serializer import BookSerializer
from rest_framework.viewsets import ViewSetMixinfrom .page import CommonPageNumberPaginationclass BookView(ViewSetMixin, GenericAPIView):queryset = Book.objects.all()serializer_class = BookSerializerpagination_class = CommonPageNumberPaginationdef list(self, request, *args, **kwargs):# 查询所有数据queryset = self.filter_queryset(self.get_queryset())# 分页处理page_list = self.paginate_queryset(queryset)if page_list:ser = self.get_serializer(page_list, many=True)return self.get_paginated_response(data=ser.data)ser = self.get_serializer(queryset, many=True)return Response(ser.data)

LimitOffsetPagination

from .page import CommonLimitOffsetPaginationclass BookView(ViewSetMixin, GenericAPIView):queryset = Book.objects.all()serializer_class = BookSerializerpagination_class = CommonLimitOffsetPaginationdef list(self, request, *args, **kwargs):# 获取查询集queryset = self.filter_queryset(self.get_queryset())# 分页处理page_list = self.paginate_queryset(queryset)if page_list:serializer = self.get_serializer(page_list, many=True)return self.get_paginated_response(serializer.data)serializer = self.get_serializer(queryset, many=True)return Response(serializer.data)

CursorPagination

from .page import CommonCursorPaginationclass BookView(ViewSetMixin, GenericAPIView):queryset = Book.objects.all()serializer_class = BookSerializerpagination_class = CommonCursorPaginationdef list(self, request, *args, **kwargs):# 获取查询集queryset = self.filter_queryset(self.get_queryset())# 分页处理page_list = self.paginate_queryset(queryset)if page_list is not None:serializer = self.get_serializer(page_list, many=True)return self.get_paginated_response(serializer.data)serializer = self.get_serializer(queryset, many=True)return Response(serializer.data)

报错

1.先写个函数
from rest_framework.views import exception_handler
from rest_framework.response import Responsedef common_exception(exc, context):res = exception_handler(exc, context)if not res:return Response({'code': 999, 'msg': f'非drf错误，错误信息是：{str(exc)}'})return Response({'code': 666, 'msg': f'这是drf错误，错误信息是：{res.data.get("detail")}'})2.在配置文件中配置：REST_FRAMEWORK = {# 以后只要除了异常，都会走这个函数'EXCEPTION_HANDLER': 'app01.exceptions.common_exception',
}