drf过滤器、分页器、筛选器的应用
一、drf 提供的过滤器(ordering)
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
# OrderingFilter排序
from rest_framework.filters import OrderingFilter,
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 配置过滤器类
filter_backends = [OrderingFilter,]
# 参与排序的字段: ordering=-price, id
ordering_fields = ['price', 'id']
请求的url为http://127.0.0.1:8000/course/free?ordering=-price,id
二、自定义过滤器
以获取的数据条数为例
filters.py
# 继承BaseFilterBackend
from rest_framework.filters import BaseFilterBackend
class LimitFilter(BaseFilterBackend):
def filter_queryset(self, request, queryset, view):
# 获取前台想要的数据条数
limit = request.query_params.get('limit')
try:
return queryset[:int(limit)]
except:
return queryset
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
# OrderingFilter排序
from rest_framework.filters import OrderingFilter,
from .filters import LimitFilter
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 配置过滤器类, 自定义过滤器类可与自带的共用
filter_backends = [OrderingFilter, LimitFilter] # LimitFilter为自定义过滤器
# 参与排序的字段: ordering=-price,id
ordering_fields = ['price']
三、群查搜索过滤器
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
# SearchFilter搜索过滤器
from rest_framework.filters import SearchFilter
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 配置搜索过滤器类
filter_backends = [SearchFilter]
# 参与搜索的字段: search = python (意思是name字段中带python就可以了)
search_fields = ['name']
请求的url为:http://127.0.0.1:8000/course/free?search=python
四、drf分页器(pagination)
paginations.py
需自定义参数
# 继承分页器类
from rest_framework.pagination import PageNumberPagination
class CoursePageNumberPagination(PageNumberPagination):
# 默认一页显示的条数
page_size = 2
# 选择哪一页的key,在url中?page=2,代表第二页
page_query_param = 'page'
# 用户自定义一页条数
page_size_query_param = 'page_size'
# 用户自定义一页最大控制条数
max_page_size = 10
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
from .paginations import CoursePageNumberPagination
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 分页器
pagination_class = CoursePageNumberPagination
请求的url为http://127.0.0.1:8000/course/free?page=1
五、偏移条数分页器(了解)
paginations.py
from rest_framework.pagination import LimitOffsetPagination
class CourseLimitOffsetPagination(LimitOffsetPagination):
# 默认一页条数
default_limit = 2
# 从offset开始往后显示limit条
limit_query_param = 'limit'
offset_query_param = 'offset'
# 最大一页最大条数
max_limit = 2
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
from .paginations import CourseLimitOffsetPagination
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 偏移分页器
pagination_class = CourseLimitOffsetPagination
请求的url:http://127.0.0.1:8000/course/free?limit=1&offset=2
六、分类筛选过滤器
1.普通使用筛选
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
# 分类筛选过滤器 pip install django-filter
from django_filters.rest_framework import DjangoFilterBackend
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 配置过滤器类
filter_backends = [DjangoFilterBackend,]
# 参与分类筛选的字段
filter_fields = ['course_category']
请求的url: http://127.0.0.1:8000/course/free?course_category=1
2.区间筛选(高级使用)
filters.py
基于django-filter插件,完成指定区间筛选(一般都是对应)数字字段
from django_filters.rest_framework.filterset import FilterSet
from django_filters import filters
from . import models
class CourseFilterSet(FilterSet):
# 自定义筛选字段 lte代表 <= 小于等于
max_price = filters.NumberFilter(field_name='price', lookup_expr='lte')
# gte 代表 >= 大于等于
min_price = filters.NumberFilter(field_name='price', lookup_expr='gte')
class Meta:
# 关联要筛选的表
model = models.Course
# 参与筛选的字段 可以是自定义字段,也可以是表中字段
fields = ['course_category', 'max_price', 'min_price']
views.py
from rest_framework.generics import ListAPIView
from . import models, serializers
# 自定义筛选器
from .filters import CourseFilterSet
class FreeCourseListAPIView(ListAPIView):
queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by('-orders').all()
serializer_class = serializers.FreeCourseModelSerializer
# 自定义筛选类
filter_class = CourseFilterSet
请求的url: http://127.0.0.1:8000/course/free?max_price=100&min_price=30