python之如何在同一api内的django rest框架中获取聚合

这是我的模型.py

from __future__ import unicode_literals 
from django.db import models 
 
class User(models.Model): 
    name = models.CharField(max_length=200) 
    company_name = models.ForeignKey('Company',on_delete=models.CASCADE,related_name='user') 
 
    def __str__(self): 
        return self.name 
 
class Company(models.Model): 
    name = models.CharField(max_length=200) 
    phone_number = models.IntegerField(null=True,blank=True) 
 
    def __str__(self): 
        return self.name 
 
class Catalog(models.Model): 
    name = models.CharField(max_length=200) 
    no_of_pcs = models.IntegerField(null=True,blank=True) 
    per_piece_price = models.DecimalField(null=True,blank=True,max_digits=10,decimal_places=2) 
    company_name = models.ForeignKey(Company,on_delete=models.CASCADE,related_name='catalog') 
 
    def __str__(self): 
        return self.name 

这是我的serializers.py

from rest_framework import serializers 
from .models import * 
from django.db.models import Sum,Avg,Max,Min,Count,F,Q 
 
class CatalogSerializer(serializers.HyperlinkedModelSerializer): 
    dynamic_data = serializers.SerializerMethodField() 
    class Meta: 
        model = Catalog 
        fields = '__all__' 
 
    def get_dynamic_data(self, obj): 
        totalpieces = Catalog.objects.all().aggregate(total_pieces=Count('no_of_pcs')) 
        totalprice = Catalog.objects.all().aggregate(total_price=Sum('per_piece_price')) 
        print(totalpieces["total_pieces"],totalprice["total_price"]) 
        return totalpieces["total_pieces"],totalprice["total_price"] 
 
 
class UserSerializer(serializers.ModelSerializer): 
    # name = serializers.StringRelatedField() 
    company_name = serializers.CharField() 
    class Meta: 
        model = User 
        fields = '__all__' 
 
class CatalogData(serializers.ModelSerializer): 
    class Meta: 
        model = Catalog 
        fields = ('name', 'no_of_pcs', 'per_piece_price') 
 
 
class CompanySerializer(serializers.ModelSerializer): 
    # catalog_details = serializers.SerializerMethodField() 
    # name = serializers.StringRelatedField() 
    catalog = CatalogData(many=True) 
    user = UserSerializer(many=True) 
    class Meta: 
        model = Company 
        fields = ('name', 'phone_number', 'catalog','user') 

这是我的views.py

from __future__ import unicode_literals 
from django.http import HttpResponse 
from .models import * 
import json 
from django.http import JsonResponse, HttpResponse 
from .serializers import * 
from rest_framework.views import APIView 
from rest_framework.response import Response 
from rest_framework import status 
from rest_framework import viewsets 
 
 
class CatalogView(viewsets.ModelViewSet): 
    queryset =  Catalog.objects.select_related('company_name') 
    serializer_class = CatalogSerializer 
 
 
class CompanyView(viewsets.ModelViewSet): 
    queryset =  Company.objects.all() 
    serializer_class = CompanySerializer 
 
class UserView(viewsets.ModelViewSet): 
    queryset =  User.objects.all() 
    serializer_class = UserSerializer 

我正在获取这样的 api..

[ 
    { 
        "url": "http://127.0.0.1:8000/catalogs/1/", 
        "dynamic_data": [ 
            3, 
            471118.0 
        ], 
        "name": "sarees", 
        "no_of_pcs": 23, 
        "per_piece_price": "33333.00", 
        "company_name": "http://127.0.0.1:8000/companies/1/" 
    } 
] 

这里的动态数据3是total no of pieces意思是aggregate Count 而在动态数据中471118.0是总价表示聚合Sum

但我期待不同格式的 api

像这样:

[ 
    { 
        "url": "http://127.0.0.1:8000/catalogs/1/", 
        "total_pieces":3, 
        "total_price": 471118.0 
        "name": "sarees", 
        "no_of_pcs": 23, 
        "per_piece_price": "33333.00", 
        "company_name": "http://127.0.0.1:8000/companies/1/" 
    } 
] 

我想在同一个 api 中获得 total_pieces 和 total_price。

谢谢,,

请您参考如下方法:

在一个函数中你返回两个值，所以 django 不会把它分开并将它作为一个列表传递，如果你想要不同的键值对使用这个

class CatalogSerializer(serializers.HyperlinkedModelSerializer): 
    total_pieces = serializers.SerializerMethodField() 
    total_price = serializers.SerializerMethodField() 
    class Meta: 
        model = Catalog 
        fields = '__all__' 
 
    def get_total_pieces(self, obj): 
        totalpieces = Catalog.objects.all().aggregate(total_pieces=Count('no_of_pcs')) 
        return totalpieces["total_pieces"] 
    def get_total_price(self, obj): 
        totalprice = Catalog.objects.all().aggregate(total_price=Sum('per_piece_price')) 
        return totalprice["total_price"]