如何在 django rest 框架中的 postgres JSONField 上应用过滤器？答案

【问题标题】：how to apply filters on a posgres JSONField in django rest framework?如何在 django rest 框架中的 postgres JSONField 上应用过滤器？
【发布时间】：2020-03-07 11:37:16
【问题描述】：

我有一个类似的模型：

# segment/models.py
from django.db import models
from django.contrib.postgres.fields import JSONField

class Segment(models.Model):
    name = models.CharField(max_length=100)
    # docs: https://docs.djangoproject.com/en/2.2/ref/contrib/postgres/fields/#jsonfield
    data = JSONField('data', 'data')

在字段数据我存储类似于此的JSON数据

{
    "length": 123.45
    "difficulty": {
        "avg": "easy"
        "max": "advanced"
    }
}

我希望能够查询如下数据：

api/segments/?data__difficulty__avg=easy

过滤所有记录

data.difficulty.avg="easy".

为此，我设置了序列化程序：

# api/serializers.py
from rest_framework import serializers

class SegmentSerializer(serializers.ModelSerializer):
    class Meta:
        model = Segment
        fields = ['id', 'name', 'data']

视图如下所示：

# api/views.py
from django_filters.rest_framework import DjangoFilterBackend
from .serializers import SegmentSerializer
from segment.models import Segment

class SegmentViewSet(viewsets.ReadOnlyModelViewSet):
    queryset = Segment.objects.all()
    serializer_class = SegmentSerializer
    filter_backends = [DjangoFilterBackend]
    filterset_fields = ['id', 'name', 'data']

当我打电话时

api/segments

我收到以下错误

AssertionError at /api/segments/
AutoFilterSet resolved field 'data' with 'exact' lookup to an unrecognized field type JSONField. Try adding an override to 'Meta.filter_overrides'. See: https://django-filter.readthedocs.io/en/master/ref/filterset.html#customise-filter-generation-with-filter-overrides

Request Method: GET
Request URL: http://localhost:8000/api/segments/
Django Version: 2.2.7
Python Executable: /Users/udos/.virtualenvs/ts/bin/python
Python Version: 3.6.4
.
.
.

我尝试将 data = serializers.JSONField() 添加到序列化程序中：

# api/serializers.py
from rest_framework import serializers

class SegmentSerializer(serializers.ModelSerializer):
    data = serializers.JSONField()
    class Meta:
        model = Segment
        fields = ['id', 'name', 'data']

但错误仍然存在。所以我没有正确应用它：|

这是如何正确完成的？

【问题讨论】：

标签： python django django-rest-framework django-filter

【解决方案1】：

我正在尝试同样的事情并找到了SearchFilter。

所以对你来说，它会是这样的：

# api/views.py
from rest_framework import filters
from .serializers import SegmentSerializer
from segment.models import Segment

class SegmentViewSet(viewsets.ReadOnlyModelViewSet):
    queryset = Segment.objects.all()
    serializer_class = SegmentSerializer
    filterset_fields = ['id', 'name']
    filter_backends = [filters.SearchFilter]
    search_fields = ['data__difficulty__avg']

【讨论】：