我已经嵌套了序列化程序，并希望通过覆盖 create 方法为其创建一个实例。

Question

我的测验应用程序有两个模型，如下所示：-

class Answer_Options(models.Model):
text = models.CharField(max_length=200)

和

class Quiz_Question(models.Model):
quiz = models.ForeignKey(Quiz, on_delete=models.CASCADE, blank=True, default=None, null=True, related_name='questions')
q_type = models.CharField(max_length=50)
text = models.CharField(max_length=200)
possible_answers = models.ManyToManyField(Answer_Options)
selected = models.ForeignKey(Answer_Options, related_name="selected", default=None, on_delete=models.CASCADE, blank=True, null=True)
correct = models.ForeignKey(Answer_Options, related_name="correct", default=None, on_delete=models.CASCADE, blank=True, null=True)
order = models.IntegerField(blank=True, null=True)

现在我想为上述模型制作序列化程序，如下所示：-

class Answer_OptionsSerializer(serializers.HyperlinkedModelSerializer):
class Meta:
model = Answer_Options
fields = ('url', 'text')

对于这样的Quiz_Question：-

class Quiz_QuestionSerializer(serializers.HyperlinkedModelSerializer):
possible_answers = Answer_OptionsSerializer(many=True)
correct = Answer_OptionsSerializer()
class Meta:
model = Quiz_Question
fields = ('url', 'quiz', 'q_type', 'text', 'possible_answers', 'selected', 'correct')

现在我面临的问题是我如何覆盖create()方法，以便我可以保存该问题的possible_answers，并保存selected以及correct选项，其中selected和correct选项必须是possible_answers列表中的值。例如，如果我的possible_answers列表是 ['A'， 'B'， 'C'， 'D']，那么selected和correct字段的值必须为'A', 'B', 'C' or 'D'。提前谢谢。

Answer 1

我已经找到了一种方法来做到这一点：-

def create(self, validated_data):
possible_answers_data = validated_data.pop('possible_answers')
selected_answers_data = validated_data.pop('selected')
correct_answers_data = validated_data.pop('correct')
quiz_question = Quiz_Question.objects.create(**validated_data)
if possible_answers_data:
for answer in possible_answers_data:
answer, created  = Answer_Options.objects.get_or_create(text=answer['text'])     
if (answer.text == correct_answers_data['text']):
print answer.text
quiz_question.correct = answer                               
quiz_question.possible_answers.add(answer)
return quiz_question