Django RestFramework分组者 [英] Django RestFramework group by

问题描述

我的问题与Django RestFramework有关，并且有关如何对元素进行分组.

My issue is related to Django RestFramework and is about how to group elements.

这是我的 serializers.py

from collaborativeAPP.models import *
from rest_framework import serializers

class VocabSerializer(serializers.ModelSerializer):
        term_word = serializers.CharField(source='term.word',read_only=True)
        kwdGroup = serializers.StringRelatedField()
        class Meta:
        model = Vocab
                fields = ('id','term_word', 'meaning','kwdGroup')

class TermSerializer(serializers.ModelSerializer):

        word = serializers.CharField(read_only=True)
        class Meta:
                model = Term
                fields = ('url', 'word')

以下json是实际结果:

The following json it's the actual result:

{"results":[
            {
                "id": 5,
                "term_word": "word1",
                "meaning": "Text1"
                "kwdGroup": "A"
            },
            {
                "id": 6,
                "term_word": "word2",
                "meaning": "Text2"
                "kwdGroup": "A"
            },
            {
                "id": 7,
                "term_word": "word3",
                "meaning": "Text3"
                "kwdGroup": "A"
            }
        ]}

您可能会注意到，"kwdGroup"是要对其进行分组的重复元素.

As you can notice "kwdGroup" is a repetitive element that i which to group.

我想按kwdGroup分组

I would like to group by kwdGroup

{"A":[
       {
        "id": 5,
        "term_word": "word1",
        "meaning": "Text1"
        },
        {
        "id": 6,
        "term_word": "word2",
        "meaning": "Text2"
        },
        {
        "id": 7,
        "term_word": "word3",
        "meaning": "Text3"
        }
    ]
}

我正在寻找 http://www.django-rest-framework.org/上的答案在api指南上，但我很难找到一种方法来领导它. 您是否也遇到同样的问题?您有什么建议吗?您是否有使用Django RestFramework处理元素分组的示例?

I'm looking for answers on http://www.django-rest-framework.org/ on api guide but i'm having difficulties to find an approach to lead with it. Do you share this same issue? Do you have any suggestion how can i do this? Do you have any example that deals with element grouping using Django RestFramework?

谢谢.

推荐答案

我们假定kwdGroup字段是与名为KeyWordGroup的模型的关系字段.

Let's assume that the kwdGroup field is the relation field to a model called KeyWordGroup.

默认ListSerializer使用to_representation方法呈现序列化对象的列表

The default ListSerializer uses the to_representation method to render a list of the serialized objects rest_framework :

class ListSerializer(BaseSerializer):
     ...

    def to_representation(self, data):
        """
          List of object instances -> List of dicts of primitive datatypes.
        """
        # Dealing with nested relationships, data can be a Manager,
        # so, first get a queryset from the Manager if needed
        iterable = data.all() if isinstance(data, models.Manager) else data

        return [
            self.child.to_representation(item) for item in iterable
        ]

我们可以修改ListSerializer以将结果分组，例如:

We can modify the ListSerializer to group the results for example:

class VocabListSerializer(serializers.ListSerializer):

     def to_representation(self, data):

         iterable = data.all() if isinstance(data, models.Manager) else data

         return {
                  kwdGroup: super().to_representation(Vocab.objects.filter(kwdGroup=kwdGroup))
                  for kwdGroup in KeyWordGroup.objects.all()
                }

然后我们可以将修改后的VocabListSerializer与VocabSerializer一起使用.

We can then use the modified VocabListSerializer with the VocabSerializer.

class VocabSerializer(serializers.Serializer):
...
    class Meta:
        list_serializer_class = VocabListSerializer

这篇关于Django RestFramework分组者的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！