首页 > 解决方案 > 覆盖 Django restframework 嵌套序列化程序的创建方法

问题描述

我正在尝试在 django-rest-framework 中使用嵌套的可写序列化程序。当我发送带有以下数据的 POST 请求时:

{
    "acc_name": "Salary Card",
    "acc_type_id": {
        "id": 2,
        "acc_type_name": "Debit Card"
    },
    "credit_amt": null,
    "bill_dt": null,
    "due_dt": null,
    "balance": "0.00",
    "comments": null
}

我收到一个错误:

Cannot assign "OrderedDict([('acc_type_name', 'Debit Card')])": "Accounts.acc_type_id" must be a "AccountTypes" instance.

我实际上为 AccountTypes 传递了 id,但为什么 restframework 会自动删除它?我该如何解决这个问题?如何使用现有帐户类型创建新帐户?

意见:

class AccountTypesViewSet(ListAPIView):
    name = __name__
    pagination_class = None
    queryset = AccountTypes.objects.filter(active='Y')
    serializer_class = AccountTypesSerializer


class AccountsViewSet(viewsets.ModelViewSet):
    pagination_class = None
    queryset = Accounts.objects.all()
    serializer_class = AccountsSerializer

楷模:

class AccountTypes(models.Model):
    id = models.AutoField(primary_key=True, editable=False)
    acc_type_name = models.CharField(max_length=50)
    active = models.CharField(max_length=1, default='Y')

    class Meta:
        db_table = f'"{schema}"."taccount_types"'
        managed = False

class Accounts(models.Model):
    id = models.AutoField(primary_key=True, editable=False)
    acc_name = models.CharField(max_length=1024)
    acc_type_id = models.ForeignKey(
        to=AccountTypes,
        db_column='acc_type_id',
        related_name='accounts',
        on_delete=models.DO_NOTHING
    )
    credit_amt = models.DecimalField(max_digits=11, decimal_places=2, null=True)
    bill_dt = models.DateField(null=True)
    due_dt = models.DateField(null=True)
    balance = models.DecimalField(max_digits=11, decimal_places=2, default=0)
    comments = models.CharField(max_length=1024, null=True)

    class Meta:
        db_table = f'"{schema}"."taccounts"'
        managed = False

序列化器:

class AccountTypesSerializer(serializers.ModelSerializer):
    class Meta:
        model = AccountTypes
        fields = ('id', 'acc_type_name')


class AccountsSerializer(serializers.ModelSerializer):
    # acc_type = serializers.SlugRelatedField(slug_field='acc_type_name', source='acc_type_id', read_only=True)
    acc_type_id = AccountTypesSerializer()

    class Meta:
        model = Accounts
        fields = ('id', 'acc_name', 'acc_type_id', 'credit_amt',
                  'bill_dt', 'due_dt', 'balance', 'comments')

    def create(self, validated_data):
        accounts_instance = Accounts.objects.create(**validated_data)
        return accounts_instance

标签: pythondjangodjango-rest-framework

解决方案


你不需要设置id字段,因为 Django 会自己做,所以删除这些行:

id = models.AutoField(primary_key=True, editable=False)

接下来,您需要发送一个id模型AccountTypes来创建新帐户,然后给 Django 一个 dict fields = ('id', 'acc_type_name')。它不知道该怎么办。所以只需发送id号码。你也不需要AccountTypesSerializer那条线acc_type_id = AccountTypesSerializer()

接下来,您应该在视图中创建帐户,而不是在序列化程序中,并且您必须在创建后保存它。


推荐阅读