Django filtering if multiple foreign key return , display only first foreign key data

Question

I want to get all the quizArchive where qbank, qset match by ID. But only those model that user's first created.

I have this model:

class QuizArchive(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="quizarchive")
    questionset = models.ForeignKey(
        "qbank.QuestionSet", on_delete=models.CASCADE, related_name="qarchive"
    )
    qbank = models.ForeignKey(
        "qbank.QuestionBank",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="qbank",
    )
    wrong = models.ManyToManyField(Question, related_name="qarchivew", blank=True)
    skipped = models.ManyToManyField(Question, related_name="qarchivesk", blank=True)
    right = models.ManyToManyField(Question, related_name="qarchiver", blank=True)
    selected_answer = models.JSONField(blank=True, null=True)
    created_time = models.DateTimeField(auto_now_add=True)
    updated_time = models.DateTimeField(auto_now=True)

    def __str__(self):
        return f"{self.user} takes {self.questionset}"

Serializer Code:

class LeaderboardSerializer(serializers.ModelSerializer):
    class Meta:
        model = QuizArchive
        fields = ["user", "wrong", "right", "skipped", "updated_time","questionset"]
    
    def to_representation(self,instance):
        leaderboard = super().to_representation(instance)
        return leaderboard

API Code:

class QSetLeaderBoard(views.APIView):
    permission_classes = [AllowAny,]
    def get(self,request,*args, **kwargs):
        qset = QuestionSet.objects.filter(id=int(kwargs.get("qset"))).first()
        qbank = QuestionBank.objects.filter(id=int(kwargs.get("qbank"))).first()
        qarchive = QuizArchive.objects.filter(qbank=qbank,questionset=qset)
        serializer = LeaderboardSerializer(qarchive,many=True)
        data = serializer.data
        return Response(data)

Result :

[
    {
        "user": 1,
        "wrong": [],
        "right": [],
        "skipped": [
            1
        ],
        "updated_time": "2022-01-26T12:44:12.055967Z",
        "questionset": 1
    },
    {
        "user": 2,
        "wrong": [
            1
        ],
        "right": [],
        "skipped": [],
        "updated_time": "2022-01-26T13:00:27.761721Z",
        "questionset": 1
    },
    {
        "user": 1,
        "wrong": [
            1
        ],
        "right": [],
        "skipped": [],
        "updated_time": "2022-01-26T12:58:52.798367Z",
        "questionset": 1
    },
    {
        "user": 2,
        "wrong": [],
        "right": [
            1
        ],
        "skipped": [],
        "updated_time": "2022-01-26T13:00:47.148016Z",
        "questionset": 1
    }
]

But I only want to unique user and their first quizarchive data by updated_time field like this:

[
    {
        "user": 1,
        "wrong": [],
        "right": [],
        "skipped": [
            1
        ],
        "updated_time": "2022-01-26T12:44:12.055967Z",
        "questionset": 1
    },
    {
        "user": 2,
        "wrong": [
            1
        ],
        "right": [],
        "skipped": [],
        "updated_time": "2022-01-26T13:00:27.761721Z",
        "questionset": 1
    }
]

SO filtered by unique user and first created quizarchive. Is this possible?

Answer 1

🙌 Filtering unique values could be done by using the .distinct() method of a QuerySet: Django docs