创建序列化器以显示正确的数据 [英] Creating serializer to display correct data
问题描述
我有4个模型。 用户
,问题
,选择和
投票
。这基本上是我要创建的民意调查应用。一个问题可以有很多选择。 投票
模型跟踪每个用户选择的答案。
I have 4 models. User
, Question
, Choice
, and Voting
. This is basically a polls app I'm trying to create. A question can have many choices. The Voting
model tracks what each user chose as their answer.
我要做的是检索所有问题,并检查登录用户为每个问题选择的选择。这是模型:
What I'd like to do is retrieve all the questions and also check what choice the logged in user selected for each question. Here's the models:
class Question(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
status = models.CharField(max_length=200)
total_votes = models.IntegerField(default=0)
class Choice(models.Model):
question = models.ForeignKey(Question, on_delete=models.CASCADE)
choice = models.CharField(max_length=120)
vote_count = models.IntegerField(default=0)
class Voting(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
choice = models.ForeignKey(Choice, on_delete=models.CASCADE)
这是我想要显示数据的方式:
Here's how I want the data displayed:
{
user: 2
status: "Hello"
total_votes: 101
choices: [
{
"id": 2,
"choice": "first choice",
"vote_count": 31,
"question": 3
},
{
"id": 4,
"choice": "second choice",
"vote_count": 70,
"question": 3
}
],
choice_selected: 2
}
在上面的数据中,登录用户在此特定问题中选择了选项2。
In the data above, the logged in user selected choice 2 in this specific question.
编辑:我尝试添加序列化程序,但显示的对象类型为'投票'不能JSON序列化
class ChoiceSerializer(serializers.ModelSerializer):
class Meta:
model = Choice
fields = '__all__'
class QuestionSerializer(serializers.ModelSerializer):
choices = ChoiceSerializer(source='choice_set', many=True)
class Meta:
model = Question
fields = '__all__'
class GetProfileQuestions(ListAPIView):
serializer_class = QuestionSerializer
def get_queryset(self):
return Question.objects.all()
此查询成功打印出每个问题及其选择。但是,如何使它也能打印出用户为每个问题选择的选项?
This query successfully prints out each question and its choices. However, how do I make it so that it also prints out which choice the user selected for each question?
class VotingSerializer(serializers.ModelSerializer):
class Meta:
model = Voting
fields = '__all__'
class ChoiceSerializer(serializers.ModelSerializer):
votes = VotingSerializer(source='voting_set', many=True)
class Meta:
model = Choice
fields = '__all__'
class QuestionSerializer(serializers.ModelSerializer):
choices = ChoiceSerializer(source='choice_set', many=True)
choice_selected = serializers.SerializerMethodField()
class Meta:
model = Question
fields = '__all__'
def get_choice_selected(self, obj):
choice_selected = Voting.objects.filter(choice__question=obj.id).filter(user=obj.user)
return choice_selected
推荐答案
我认为您会在自己的QuestionSerializer类中使用它
I think you will want this in your QuestionSerializer class
choice_selected = serializers.SerializerMethodField()
并在QuestionSerializer中定义类似于以下内容的方法……
and define a method that looks something like this in QuestionSerializer …
def get_choice_selected(self, obj):
choice_selected = Voting.objects.filter(choice__question=obj.id).filter(user=obj.user)
return choice_selected
以上未经测试。
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