First, the use of filters drf

drf Filters: In this view GenericAPIView base class def filter_queryset(self, queryset)method through the self.filter_backendsconfiguration of the filter and get used. However drf default configuration settings file is empty, neither the filter.
drf provides two default filter class for us
- class OrderingFilter(BaseFilterBackend)For sorting
  
  When use: Add field configuration involved in sorting url
- class SearchFilter(BaseFilterBackend)For search
  
  When using: Participation in the search field configuration add url
If we want to use a filter may be by local configuration and the global configuration to use

Local configuration:

from rest_framework.generics import ListAPIView
# OrderingFilter排序、SearchFilter搜索
from rest_framework.filters import OrderingFilter, SearchFilter

class FreeCourseListAPIView(ListAPIView):
    queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by(
        "-orders").all()
    serializer_class = serializers.FreeCourseModelSerializer

    # 局部配置过滤器类
    filter_backends = [OrderingFilter, SearchFilter]
    
    # 参与排序的字段: ordering=-price,id,students
    ordering_fields = ['price', 'id', 'students']
    
    # 参与搜索的字段: search=python  (name字段中带python就ok)
    search_fields = ['name', 'brief']

# 携带排序的过滤参数的url: http://127.0.0.1:8000/course/free?ordering=-price 降序
# 携带搜索的过滤参数的url: http://127.0.0.1:8000/course/free?search=python (name字段中带python就ok)

Second, custom filter

Custom filter class. Inherited BaseFilterBackendclass (actually read the source code you will know that following the inheritance can not, because BaseFilterBackendthe class and there is no substantive things to do)
Achieve def filter_queryset (self, request, queryset , view) method, an object must return a queryset

Custom filter class

from rest_framework.filters import BaseFilterBackend
# 自定义过滤器类
class LimitFilter(BaseFilterBackend):
    # 必须实现filter_queryset方法，返回queryset对象
    def filter_queryset(self, request, queryset, view):
        # 取出过滤条件
        limit = request.query_params.get("limit")   # 过滤参数
        try:
            return queryset[:int(limit)]
        except:
            return queryset

Use custom filter class

from . import filters
class FreeCourseListAPIView(ListAPIView):
    queryset = models.Course.objects.filter(is_delete=False, is_show=True).order_by(
        "-orders").all()
    serializer_class = serializers.FreeCourseModelSerializer
    
    # 局部配置过滤器类
    filter_backends = [filters.LimitFilter]
    
# 携带自定义过滤字段参数的url: http://127.0.0.1:8000/course/free?limit=1

Third, the use django-filter module

django-filter module can do some more advanced filtering, you can also customize the filter, such as classification screening, screening interval, etc.

Installation depends: pip install django-filter

django django-filter modules and drf have done the appropriate support. If drf do before and after the end of the separation project on the use offrom django_filters.rest_framework import DjangoFilterBackend

use:

Local configuration filter class:filter_backends = [DjangoFilterBackend]

Sort of fields involved:filter_fields = ['course_category'] (see the source code that, in fact, reflected in the source field name two, are: filterset_fields、filter_fieldsthe reflection of the two class names, are: filterset_class、filter_class、)

# 分类筛选：django-filter：filter_backends配置DjangoFilterBackend，再在filter_fields中配置分组筛选的字段
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
    
    # 局部配置过滤器类
    filter_backends = [DjangoFilterBackend]
    # 参与分类筛选的字段：
    filter_fields = ['course_category']

# 携带分类筛选字段的参数的url: http://127.0.0.1:8000/course/free?course_category=2

3.1 custom filter class implements price range based django-filter module

Custom filter class. Inherited from django_filters.rest_framework.filterset import FilterSetclass
Sort custom fields. Meta class to specify the filter fields by fields. Class and method definitions consistent sequence