django Filtering 使用

django-filter是单独的一个库，不属于djangorestframework中的，属于外部库引用进来使用。下面就来介绍下filter

有三种filter方式:

DjangoFilterBackend
SearchFilter
OrderingFilter

准备工作

首先需要安装django-filter

pip install django-filter

然后需要将django_filters 添加到 INSTALLED_APPS中

INSTALLED_APPS = [
    'django_filters',
]

DjangoFilterBackend

使用默认的过滤

在View中添加filter_backends属性,设置过滤方式DjangoFilterBackend，并且设置过滤的属性。


from django_filters.rest_framework import DjangoFilterBackend

class GoodsListViewSet(ModelViewSet):    
    queryset = Goods.objects.all()    
    serializer_class = GoodsSerializer    
    pagination_class = MyPagination    
    filter_backends = (DjangoFilterBackend,)    
    filterset_fields = ('name', 'shop_price')

在调试界面中会出现过滤器选项, 可以在其中过滤name和shop_price两个属性的值
在这里插入图片描述

自定义过滤

创建filters.py，在里面定义自己的过滤器。
可以通过最小的价格、最大的价格，和模糊查询名字去过滤想要的数据。

from django_filters import FilterSet, NumberFilter, CharFilter
from .models import Goods

class GoodsFilter(FilterSet):   
    """    商品的过滤类    """    
    price_min = NumberFilter(field_name='shop_price', help_text="最低价格", lookup_expr='gte')    
    price_max = NumberFilter(field_name='shop_price', lookup_expr='lte')    
    name = CharFilter(field_name='name', lookup_expr="icontains")    
    class Meta:        
        model = Goods        
        fields = ['price_min', 'price_max', 'name']

将该过滤器添加到view中
view.py

class GoodsListViewSet(ModelViewSet):    
    queryset = Goods.objects.all()    
    serializer_class = GoodsSerializer   
    pagination_class = MyPagination    
    filter_backends = (DjangoFilterBackend,)    
    filter_class = GoodsFilter

最后可以通过 http://127.0.0.1:8000/goods/?price_min=150&price_max=160&name=水果 去过滤得到想要的数据。

SearchFilter

这个Filter是基于Django的搜索。现在我们将SearchFilter集成到过滤里面来。在filter_backends中添加SearchFiler，然后再在search_fields中添加需要搜索的字段即可，在搜索的字段前面字符变量来提高搜索效率。

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

view.py

from rest_framework.filters import SearchFilter

class GoodsListViewSet(ModelViewSet):    
    queryset = Goods.objects.all()    
    serializer_class = GoodsSerializer    
    pagination_class = MyPagination    
    filter_backends = (DjangoFilterBackend, SearchFilter)    
    filter_class = GoodsFilter    
    search_fields = ("=name", 'goods_brief', 'goods_desc')

OrderingFilter

可以对数据进行排序筛选数据。我们将其加入进去

view.py

from rest_framework.filters import SearchFilter, OrderingFilter



class GoodsListViewSet(ModelViewSet):    
    queryset = Goods.objects.all()    
    serializer_class = GoodsSerializer    
    pagination_class = MyPagination    
    filter_backends = (DjangoFilterBackend, SearchFilter, OrderingFilter) 
    filter_class = GoodsFilter    
    search_fields = ("=name", 'goods_brief', 'goods_desc')
    ordering_fields = ("sold_num", "add_time")

自定义过滤条件

修改filters.py文件，编写过滤方法top_category_filter绑定到top_category字段中，即可通过该属性名进行相应的筛选。

class GoodsFilter(FilterSet):    
    """    商品的过滤类    """    
    pricemin = NumberFilter(field_name='shop_price', help_text="最低价格", lookup_expr='gte')    
    pricemax = NumberFilter(field_name='shop_price', lookup_expr='lte')    
    name = CharFilter(field_name='name', lookup_expr="icontains")   
    top_category = NumberFilter(method='top_category_filter')    
    
    def top_category_filter(self, queryset, name, value):        
        return queryset.filter(Q(category_id=value) | Q(category__parent_category_id=value) | (category__parent_category__parent_category_id=value))
    
    class Meta:        
        model = Goods
        fields = ['pricemin', 'pricemax', 'name']