如何在Django RestFramework中實現一對多關系？

Question

在這里我提到了我的model.py和serilaizers.py我想在這里使用一對多的概念。 我期待這樣的輸出。

預期產出

{
    "id": 1,        
    "product_name": "Rice",
    "description": "expired on 13-04-2018",
    "sales": "55",
    "cost": "55",
    "tax_details": [
        {
            'id': 1,
            'tax_name': "http://127.0.0.1:8000/tax/1/",
            'percentage': 10
        }, {
            'id': 2,
            'tax_name': "http://127.0.0.1:8000/tax/3/",
            'percentage': 2
        }, {
            'id': 3,
            'tax_name': "http://127.0.0.1:8000/tax/2/",
            'percentage': 05
        },
        ... 
    ],
}

Models.py

TAX模型

這是主要的稅表這里我將維修稅名如（IGST，GST，VAT）這是一個下拉列表。

產品

這里包含產品詳細信息，我在預期輸出中提到過

TaxProduct

在此模型中，輸入的稅名和百分比應存儲單獨的模型。

  class tax(models.Model)
      tax_name = models.CharField(max_length = 250)
      percentage = models.CharField(max_length = 250)

  class Taxproduct(models.Model):
      tax_name = ForeignKey(tax, on_delete = models.CASCADE)
      percentage = models.CharField(max_length = 3)

  class Product(models.Model):
      product_name =  models.CharField(max_length = 25)
      description = models.CharField(max_length = 150)
      category = models.ForeignKey(Category, on_delete = models.CASCADE)
      sales = models.CharField(max_length = 25)
      cost = models.CharField(max_length = 25)
      tax_details = models.CharField(max_length = 250)

串行

  class TaxSerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
      model = Tax
      fields = ('id','tax_name', 'tax_percentage')
  class TaxproductSerializer(serializers.HyperlinkedModelSerializer):
      class Meta:
      model = Taxproduct
      fields = ('id', 'tax_name', 'percentage')

  class ProductSerializer(serializers.HyperlinkedModelSerializer):
      tax_details = TaxproductSerializer(many=True, read_only = True)
  class Meta:
      model = Product
      fields = ('id', 'image','pro_name', 'description', 'sales', 'cost', 'tax_details')

所以請告訴我怎么做？

Answer 1

首先，您需要為模型添加一對多關系。 為此，您需要將ForeignKkey字段添加到Taxproduct模型：

class Taxproduct(models.Model)
    tax_name = models.CharField(max_length=250)
    percentage=models.CharField(max_length=250)
    product = models.ForeignKey(Product, on_delete=models.CASCADE)

這將添加到Product模型屬性taxproduct_set ，它將返回相關稅的列表。 要將其添加到具有不同名稱的序列化程序（在您的情況下為tax_details ，請使用字段的source參數：

class ProductSerializer(serializers.HyperlinkedModelSerializer):
    tax_details = TaxproductSerializer(many=True,read_only=True, source='taxproduct_set')
    class Meta:
        model = Product
        fields = ('id','pro_name','description','sales','cost','tax_details')