是否可以进行模糊过滤搜索？ （过滤一组值的字段）

Question

我来自这个问题https://github.com/carltongibson/django-filter/issues/919，这是发生了什么：

我想通过 django-filter 对列表进行一些模糊搜索（某些列表搜索和单个模糊搜索都可以）。

一、产品型号：

from django.db import models


class Product(models.Model):
    ...
    name = models.CharField(max_length=16)
    type = models.CharField(max_length=16)
    ...

以及存储在数据库中的两个产品：

{
  "name": "tomato",
  "type": "vegetable"
}

{
  "name": "orange",
  "type": "fruit"
}

和序列化器：

from rest_framework import serializers

from .models import Product


class ProductSerializer(serializers.ModelSerializer):
    name = serializers.CharField()
    type = serializers.CharFIeld()

    class Meta:
        model = Product
        fields = '__all__'

然后ListFilter:

import django_filters
from django_filters.fields import Lookup

from .models import Product


class ListFilter(django_filters.Filter):
    def filter(self, qs, value):
        value_list = value.split(u',')
        return super(ListFilter, self).filter(qs, Lookup(value_list, 'in'))

然后查看（我将ListFilter 放在utils.django_filters）：

from rest_framework import generics
from django_filters import rest_framework as filters

from utils.django_filters import ListFilter

from .models import Product
from .serializers import ProductSerializer


class ProductFilter(filters.FilterSet):
    type = ListFilter(name='type')

    class Meta:
        model = Product
        fields = {
            'type': ['exact', 'contains'],
        }


class ProductList(generics.ListCreateAPIView):
    queryset = Product.objects.all()
    serializer_class = ProductSerializer
    filter_backends = (filters.DjangoFilterBackend,)
    filter_class = ProductFilter

最后的网址：

from django.urls import path

from . import views


path('product-list', views.ProductList.as_view(), name='product-list')

以下是测试用例和结果：

GET /api/product/product-list?type=fruit -> [orange]

GET /api/product/product-list?type=vegetable -> [tomato]

GET /api/product/product-list?type=fruit,vegetable -> [orange, tomato]

GET /api/product/product-list?type__contains=fru -> [orange]

GET /api/product/product-list?type__contains=vege -> [tomato]

GET /api/product/product-list?type__contains=fru,vege -> []

GET /api/product/product-list?type__contains=fruit,vegetable -> []

我希望最后两个结果是[orange, tomato]，可以这样做吗？

Answer 1

终于按照rpkilby的answer解决了这个问题：

from functools import reduce
from operator import or_

from django.db.models import Q
from django_filters import Filter, CharFilter
from django_filters.fields import Lookup
from django_filters.filters import BaseCSVFilter


SPLIT_SIGN = u','


class ListFilter(Filter):
    def filter(self, qs, value):
        value_list = value.split(SPLIT_SIGN)
        return super(ListFilter, self).filter(qs, Lookup(value_list, 'in'))


def gen_fuzzy_list_filter(attr_name):
    class CharListFilter(BaseCSVFilter, CharFilter):
        @staticmethod
        def filter(qs, value):
            # BaseCSVFilter produces/validates a list of values
            value_list = SPLIT_SIGN.join(value).split(SPLIT_SIGN)
            queries = [Q(**{attr_name: val}) for val in value_list]
            return qs.filter(reduce(or_, queries))

    return CharListFilter

然后在过滤器中：

class ProductFilter(filterset.FilterSet):
    type = ListFilter(name='type')
    type__contains = gen_fuzzy_list_filter('type__contains')(field_name='type', lookup_expr='contains')

Answer 2

尝试使用 Django Fulltext Search 之类的 TrigramSimilarity 搜索，但前提是您的数据库是 PostgreSQL。

对于其他数据库，可以使用在查询集上运行模糊搜索的外部 python 包。