• Django REST framework 分页


    参考链接: https://www.cnblogs.com/liwenzhou/p/9398959.html

    rest framework中提供了三种分页模式:
    
    from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination

    PageNumberPagination

    分页规则

    按页码数分页,第n页,每页显示m条数据

    例如:http://127.0.0.1:8000/api/article/?page=2&size=1

    配置分页类:

    class MyPageNumber(PageNumberPagination):
        page_size = 2  # 每页显示多少条
        page_size_query_param = 'size'  # URL中每页显示条数的参数
        page_query_param = 'page'  # URL中页码的参数
        max_page_size = None  # 最大页码数限制

    视图:

    # 分页
    from rest_framework.pagination import PageNumberPagination
    
    class MyPageNumberPagination(PageNumberPagination):
    
        page_size = 10  # 每页显示多少条
        max_page_size = 10  # # 最大页码数限制
    
        page_size_query_param = 'size'  # URL中每页显示条数的参数
        page_query_param = 'page'  # URL中页码的参数
    
    
    # 分页
    class BookView(APIView):
    
        def get(self, request):
    
            book_list = Book.objects.all()
            # # 分页(原理)
            page_obj = MyPageNumberPagination()
            # # 在序列化之前就进行分页
            # books_pag = pnp.paginate_queryset(book_list, request,self)
            books_pag = page_obj.paginate_queryset(queryset=book_list, request=request, view=self)
            bs = BookModelSerializers(books_pag, many=True)
            return Response(bs.data)

    返回带下一页页码链接的响应

    路由:

    urlpatterns = [
    
        re_path(r"^Books/$", views.BookView.as_view(), name='book'),
        # re_path(r"^Book/(?P<pk>d+)/$", views.BookDetailView.as_view(), name='book'),
        re_path(r"^Book/(?P<id>d+)/$", views.BookDetaiView.as_view(), name='books'),
    ]

    序列化:

    from rest_framework import serializers
    
    
    class BookModelSerializers(serializers.ModelSerializer):
        # 自定义publish字段超链接路径
        depth = 1  # 0 ~ 10
        publish = serializers.HyperlinkedIdentityField(view_name='books',
                                                       lookup_field='publish_id',
                                                       lookup_url_kwarg='id')
    
        """
        # view_name参数 进行传参的时候是参考路由匹配中的name与namespace参数
        #  lookeup_field参数是根据在UserInfo表中的连表查询字段group_id
        # look_url_kwarg参数在做url反向解析的时候会用到
        """
    
        class Meta:
            model = Book
            # fields = ['id', 'title', 'pub_date', 'publish', 'authors']# 这个是可以自定义字段的
            fields = "__all__"
            depth = 0
            # 自动向内部进行深度查询,就是查询的比较详细  depth表示查询层数

    配置分页类:

    # 分页
    from rest_framework.pagination import PageNumberPagination
    
    class MyPageNumberPagination(PageNumberPagination):
        page_size = 10  # 每页显示多少条
        max_page_size = 10  # # 最大页码数限制
    
        page_size_query_param = 'size'  # URL中每页显示条数的参数
        page_query_param = 'page'  # URL中页码的参数

    视图:

    查询所有:

    class BookView(APIView):
        def get(self, request, *args, **kwargs):
            book_list = Book.objects.all()
            page_obj = MyPageNumberPagination()
            # 在序列化之前就进行分页
            books_pag = page_obj.paginate_queryset(queryset=book_list, request=request, view=self)
            # context十分关键,如果不将request传递给它,在序列化的时候,图片与文件这些Field不会再前面加上域名,也就是说,只会有/media/img...这样的路径!
            bs = BookModelSerializers(instance=books_pag, many=True, context={'request': request})  # 在做链接的时候需要添加context参数
            print(bs)
            # 默认就返回json格式的字符串
    
            return page_obj.get_paginated_response(bs.data)

    查询单个:

    class BookDetaiView(APIView):
        # inquire database
        def get(self, request, id, *args, **kwargs):
            book_list = Book.objects.filter(id=id)
            bs = BookModelSerializers(instance=book_list, many=True, context={'request': request})  # 在做链接的时候需要添加context参数
            print(bs)
            # 默认就返回json格式的字符串
            return Response(bs.data)

    LimitOffsetPagination 

    分页规则:

    分页,在n位置,向后查看m条数据

    例如:http://127.0.0.1:8000/api/article/?offset=2&limit=2

    配置分页类:

    # offset分页
    class MyLimitOffset(LimitOffsetPagination):
        default_limit = 1   # 默认向后看1条数据
        limit_query_param = 'limit'  # url向后取多少条数据
        offset_query_param = 'offset'  # url 以它为基准向后取数据
        max_limit = 999     # 最大看几条数据

    路由:

    urlpatterns = [
    
        re_path(r"^Books/$", views.BookView.as_view(), name='book'),
        # re_path(r"^Book/(?P<pk>d+)/$", views.BookDetailView.as_view(), name='book'),
        re_path(r"^Book/(?P<id>d+)/$", views.BookDetaiView.as_view(), name='books'),
    ]

    序列化:

    from rest_framework import serializers
    
    
    class BookModelSerializers(serializers.ModelSerializer):
        # 自定义publish字段超链接路径
        depth = 1  # 0 ~ 10
        publish = serializers.HyperlinkedIdentityField(view_name='books',
                                                       lookup_field='publish_id',
                                                       lookup_url_kwarg='id')
    
        """
        # view_name             参数 进行传参的时候是参考路由匹配中的name与namespace参数
        #  lookeup_field        参数是根据在UserInfo表中的连表查询字段group_id
        # look_url_kwarg         参数在做url反向解析的时候会用到
        """
    
        class Meta:
            model = Book
            # fields = ['id', 'title', 'pub_date', 'publish', 'authors']# 这个是可以自定义字段的
            fields = "__all__"
            depth = 0
            # 自动向内部进行深度查询,就是查询的比较详细  depth表示查询层数

    视图:

    查询所有:

    from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination
    
    
    # offset分页
    class MyLimitOffset(LimitOffsetPagination):
        default_limit = 1   # 默认向后看1条数据
        limit_query_param = 'limit'  # url向后取多少条数据
        offset_query_param = 'offset'  # url 以它为基准向后取数据
        max_limit = 999     # 最大看几条数据
    
    
    class BookView(APIView):
        def get(self, request, *args, **kwargs):
            book_list = Book.objects.all()
            # 分页
            page_obj = MyLimitOffset()
            page_article = page_obj.paginate_queryset(queryset=book_list, request=request, view=self)
            # 序列化
            bs = BookModelSerializers(instance=page_article, many=True, context={'request': request})  # 在做链接的时候需要添加context参数
            # 返回分页 url
            return page_obj.get_paginated_response(bs.data)

    查询单个:

    class BookDetaiView(APIView):
        # inquire database
        def get(self, request, id, *args, **kwargs):
            book_list = Book.objects.filter(id=id)
            bs = BookModelSerializers(instance=book_list, many=True, context={'request': request})  # 在做链接的时候需要添加context参数
            print(bs)
            # 默认就返回json格式的字符串
            return Response(bs.data)

     

    CursorPagination

    分页规则:

    加密分页,把上一页和下一页的id值记住

    配置分页类:

    # 加密分页
    class MyCursorPagination(CursorPagination):
        cursor_query_param = 'cursor'  # 查询的key值
        page_size = 3  # #每页显示的大小
        ordering = '-id' # 重写要排序的字段

    视图:

    查询所有:

    class BookView(APIView):
        def get(self, request, *args, **kwargs):
            book_list = models.Book.objects.all().order_by("id")
            # 实例化产生一个偏移分页对象
            page_obj = MyCursorPagination()
            page_article = page_obj.paginate_queryset(queryset=book_list, request=request, view=self)
            # 序列化
            bs = BookModelSerializers(instance=page_article, many=True,
                                      context={'request': request})  # 在做链接的时候需要添加context参数
            # # 去setting中配置每页显示多少条
            return page_obj.get_paginated_response(bs.data)

    查询单个:

    class BookDetaiView(APIView):
        # inquire database
        def get(self, request, id, *args, **kwargs):
            book_list = models.Book.objects.filter(id=id)
            bs = BookModelSerializers(instance=book_list, many=True, context={'request': request})  # 在做链接的时候需要添加context参数
            print(bs)
            # 默认就返回json格式的字符串
            return Response(bs.data)

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  • 原文地址:https://www.cnblogs.com/Rivend/p/12057845.html
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