drf-排序、过滤、分页、异常处理

from .models import Book
from .serializer import BookSerializer
## 方式一：使用内置的过滤类
from rest_framework.filters import SearchFilter, OrderingFilterclass BookView(ViewSetMixin, ListAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    # 方式一：内置的
    # 查询方式http://127.0.0.1:8000/books/?search=29  #模糊匹配： 只要名字中有29或价格中有29都能搜出来
    filter_backends = [SearchFilter]
    # filter_backends = [SearchFilter, OrderingFilter] #先过滤然后再排序
    search_fields = ['name', 'price'] # 按名字或价格排序

from .models import Book
from .serializer import BookSerializer
from django_filters.rest_framework import DjangoFilterBackend
class BookView(ViewSetMixin, ListAPIView):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    # 方式二：精准匹配--》django-filter
    # http://127.0.0.1:8000/books/?name=红楼梦
    # http://127.0.0.1:8000/books/?price=19&name=西游记
    filter_backends = [DjangoFilterBackend]
    filterset_fields=['name','price']

from rest_framework.filters import BaseFilterBackend
from django.db.models import Q

class MyFilter(BaseFilterBackend):
    def filter_queryset(self, request, queryset, view):
        # 基于queryset 进行过滤，过滤后返回即可
        # http://127.0.0.1:8000/books/?name=书   # 名字中有书的就查出来
        search_param = request.query_params.get('name')
        price = request.query_params.get('price')
        if search_param and price:
            # queryset = queryset.filter(Q(name__contains=search_param) | Q(price=price))  # qs对象的filter
            queryset = queryset.filter(name__contains=search_param,price=price)  # qs对象的filter
        return queryset

class BookView(ViewSetMixin, APIView):
    def list(self, request, *args, **kwargs):
        # 按名字过滤
        print('asfdasdf')
        name = request.query_params.get('name')
        book_list = Book.objects.all().filter(name__contains=name)
        ser = BookSerializer(instance=book_list, many=True)
        return Response(ser.data)

from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination

#方式一：
class CommonPageNumberPagination(PageNumberPagination):
    # web 用这个多
    # http://api.example.org/accounts/?page=4
    # http://api.example.org/accounts/?page=4&page_size=100
    # 重写几个类属性
    page_size = 3  # 每页显示多少条
    page_query_param = 'page'  # 指定第几页的key 值   page=4

    page_size_query_param = 'size'  # 可以指定每页显示多少条 size=300000
    max_page_size = 5  # 每页最多显示5条

#方式二：
class CommonLimitOffsetPagination(LimitOffsetPagination):
    # http://api.example.org/accounts/?limit=4   # 从开始取4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2条
    limit_query_param = 'limit'  # 每页显示多少条的查询条件
    offset_query_param = 'offset' # 从第几条开始取数据
    max_limit = 5   # limit最多取5条
# 方式三：
class CommonCursorPagination(CursorPagination):
    # app上用这个多
    # 只能上一页和下一页，不能指定跳转到中间的某页---》效率高，大数据量用它、
    cursor_query_param = 'cursor'  # 查询条件，用不到，需要有
    page_size = 2  # 每页显示两条
    ordering = 'id'  # 按id排序 这个必须是表中字段

from .page import CommonPageNumberPagination,CommonLimitOffsetPagination,CommonCursorPagination
class BookView(ViewSetMixin, ListAPIView):
    authentication_classes=[]
    queryset = Book.objects.all()
    serializer_class = BookSerializer
    pagination_class =CommonCursorPagination   # 分页方式只有一种，配置一个类即可

class BookView(ViewSetMixin, APIView):
    authentication_classes=[]
    def list(self,request,*args,**kwargs):
        book_list=Book.objects.all()
        pagination =CommonPageNumberPagination()
        page=pagination.paginate_queryset(book_list,request)
        ser=BookSerializer(instance=page,many=True)
        return Response(ser.data)

# 'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler',
from rest_framework.views import exception_handler
from rest_framework.response import Response

def common_exception(exc, context):
    # 执行一下原来的exception_handler---》它能处理drf的异常，我就不用处理了
    res = exception_handler(exc, context)
    if not res:  # 有值，说明是drf异常，它处理完了，没有值，是其他异常，我们自己处理
        return Response({'code': 999, 'msg': '非drf错误，错误信息是：%s' % str(exc)})
    else:
        return Response({'code': 888, 'msg': 'drf错误，错误信息是：' + res.data.get('detail')})