在 django rest 框架中使用序列化程序时出现 AttributeError

Question

当我尝试使用 djangorestframework 序列化 django 模型时，我得到 'AttrbuteError: 'DeferredAttribute' has no attribute 'isoformat'' 下面是我试图序列化的模型

class PrimaryRecord(models.Model):
      primaryId = models.AutoField(primary_key=True)
      primary_track = models.CharField(max_length=30)
      title = models.CharField(max_length=255)
      start_date = models.DateField()
      create_date = models.DateField()
      year = models.IntegerField()

下面是我使用的序列化器类

from rest_framework import serializers
from snippets.models import Assesor, PrimaryRecord, PrimaryAssesor

class PrimaryRecordSerializer(serializers.Serializer):
      primary_track = serializers.CharField(max_length=30)
      title = serializers.CharField(max_length=255)
      start_date = serializers.DateField(format = None)
      create_date = serializers.DateField(format = None)
      year = serializers.IntegerField()

  def create(self, validated_data):
      return PrimaryAssesor.objects.create(**validated_data)

  def update(self, instance, validated_data):
      instance.primary_track = validated_data.get('primary_track', instance.primary_track)
      instance.title = validated_data.get('title', instance.title)
      instance.start_date = validated_data.get('start_date', instance.start_date)
      instance.create_date = validated_data.get('create_date', instance.create_date)
      instance.year = validated_data.get('year', instance.year)
      instance.save()
      return instance

我正在关注this 学习 djangorestframework 的教程。

我执行以下步骤

p1 = PrimaryRecord(primary_track='P2017-98',title='ABC',start_date=date(2017,6,23),create_date=timezone().now(),year=2017)
p1.save()
serializer = PrimaryRecordSerializer(primaryrecord)
serializer.data # the error occurs here

 'AttrbuteError: 'DeferredAttribute' has no attribute 'isoformat''

Answer 1

在初始化 PrimaryRecordSerializer 序列化程序时，您使用了错误的变量 primaryrecord 而不是 p1。应该是，

serializer = PrimaryRecordSerializer(p1)

不是

serializer = PrimaryRecordSerializer(primaryrecord)