DjangoRest中使用filter

DjangoRest中使用filter

在繼承了GenericAPIView以及其子類的view中可以設置filter_backends屬性來使用filter.

例如：

from rest_framework import filters

filter_backends = (filters.OrderingFilter, filters.SearchFilter)

filter分類

1. DjangoFilterBackend (django_filters.rest_framework中)

參考文檔 Integration with DRF

• Using the new FilterSet simply requires changing the import path. Instead of importing from django_filters, import from the rest_framework sub-package. Your view class will also need to add DjangoFilterBackend to the filter_backends.

  from django_filters import rest_framework as filters
  
  class ProductList(generics.ListAPIView):
      queryset = Product.objects.all()
      serializer_class = ProductSerializer
      filter_backends = (filters.DjangoFilterBackend,)
      filterset_fields = ('category', 'in_stock')
  

• If you want to use the django-filter backend by default, add it to the DEFAULT_FILTER_BACKENDS setting.

  # settings.py
  INSTALLED_APPS = [
      ...
      'rest_framework',
      'django_filters',
  ]
  
  REST_FRAMEWORK = {
      'DEFAULT_FILTER_BACKENDS': (
          'django_filters.rest_framework.DjangoFilterBackend',
          ...
      ),
  }
  

• Adding a FilterSet with filterset_class

  To enable filtering with a FilterSet, add it to the filterset_class parameter on your view class.

  from rest_framework import generics
  from django_filters import rest_framework as filters
  from myapp import Product
  
  
  class ProductFilter(filters.FilterSet):
      min_price = filters.NumberFilter(field_name="price", lookup_expr='gte')
      max_price = filters.NumberFilter(field_name="price", lookup_expr='lte')
  
      class Meta:
          model = Product
          fields = ['category', 'in_stock', 'min_price', 'max_price']
  
  
  class ProductList(generics.ListAPIView):
      queryset = Product.objects.all()
      serializer_class = ProductSerializer
      filter_backends = (filters.DjangoFilterBackend,)
      filterset_class = ProductFilter
  

• Using the filterset_fields shortcut

  You may bypass creating a FilterSet by instead adding filterset_fields to your view class. This is equivalent to creating a FilterSet with just Meta.fields.

  from rest_framework import generics
  from django_filters import rest_framework as filters
  from myapp import Product
  
  
  class ProductList(generics.ListAPIView):
      queryset = Product.objects.all()
      filter_backends = (filters.DjangoFilterBackend,)
      filterset_fields = ('category', 'in_stock')
  
  
  # Equivalent FilterSet:
  class ProductFilter(filters.FilterSet):
      class Meta:
          model = Product
          fields = ('category', 'in_stock')
  

  Note that using filterset_fields and filterset_class together is not supported.

  如何自定義FilterBackend？

  在filter_backends加入自定義的FilterBackend

  self.filter_backends += (UsersStateFilterBackend,)

  from rest_framework import filters
  from django.db.models import Q
  
  class UsersStateFilterBackend(filters.BaseFilterBackend):
  """
  Filter users objects.
  """
  def filter_queryset(self, request, queryset, view):
      request_data = request.GET
      is_active = request_data.get('is_active', '')
      if is_active == '0':
          queryset = OpsUser.objects.filter(Q(is_deleted=False), Q(is_active=False)).all().order_by('id')
      elif is_active == '1':
          queryset = OpsUser.objects.filter(Q(is_deleted=False), Q(is_active=True)).all().order_by('id')
  
      return queryset
  

2. SearchFilter (rest_framework.filters中)

• The SearchFilter class will only be applied if the view has a search_fields attribute set. The search_fields attribute should be a list of names of text type fields on the model, such as CharField or TextField.

  from rest_framework import filters
  
  class UserListView(generics.ListAPIView):
      queryset = User.objects.all()
      serializer_class = UserSerializer
      filter_backends = [filters.SearchFilter]
      search_fields = ['username', 'email']
  

  This will allow the client to filter the items in the list by making queries such as:

  http://example.com/api/users?search=russell
  # 只需要russel匹配search_fields中任意item的限制規則
  

  You can also perform a related lookup on a ForeignKey or ManyToManyField with the lookup API double-underscore notation:

  search_fields = ['username', 'email', 'profile__profession']

• By default, searches will use case-insensitive partial matches. The search parameter may contain multiple search terms, which should be whitespace and/or comma separated. If multiple search terms are used then objects will be returned in the list only if all the provided terms are matched.

  # 例如以下請求
  # 需要russell，aaa同時匹配search_fields中任意item的限制規則
  http://example.com/api/users?search=russell，aaa
  

• 可以通過在search_fields前面添加各種字符來限制搜索行爲

  • ‘^’ Starts-with search.
  • ‘=’ Exact matches.
  • ‘@’ Full-text search. (Currently only supported Django’s PostgreSQL backend.)
  • ‘$’ Regex search.

3. OrderingFilter (rest_framework.filters中)

• The OrderingFilter class supports simple query parameter controlled ordering of results.

  from rest_framework import filters
  class UserListView(generics.ListAPIView):
      queryset = User.objects.all()
      serializer_class = UserSerializer
      filter_backends = [filters.OrderingFilter]
      ordering_fields = ['username', 'email']
      ordering = ['username']
  

  Note:

  • ordering 查詢結果集默認排序
  • ordering_fields API應在排序過濾器中允許的字段

• 默認查詢參數爲ordering

  # order users by username
  http://example.com/api/users?ordering=username
  
  # reverse orderings by prefixing the field name with '-'
  http://example.com/api/users?ordering=-username
  
  # Multiple orderings
  http://example.com/api/users?ordering=account,username