Q:

Django Rest Framework, display data from a table referenced with a foreign key

I got stuck a bit with a small problem when doing my school project, the problem is that I have an api with DRF and wanting to show my patient data "main table" shows them without problems but when I want to show other patient data in a different table (this table is this reference with a foreign key to Patient) I have not managed to obtain the patient data from this other table.
I can not make my api send me the other patient data from the foreign key referenced to the patient, could you help me?
models.py
class Paciente(TimeStampedModel):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    udi = models.UUIDField(default=uuid.uuid4, editable=False)
    first_name = models.CharField('Nombre(s)', max_length=100)
    last_name = models.CharField('Apellidos', max_length=100)
    gender = models.CharField('Sexo', max_length=20, choices=GENDER_CHOICES)
    birth_day = models.DateField('Fecha de nacimiento', blank=True, null=True)
    phone_number = models.CharField('Número de telefono', max_length=13)
    civil_status = models.CharField('Estado civil', max_length=20, choices=CIVIL_STATUS_CHOICES)
    etc.....

class Antecedentes(TimeStampedModel):
    """
    Modelo de motivo y antecedentes de la enfermedad presentada en el momento de
    la consulta
    """
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    paciente = models.ForeignKey(Paciente, on_delete=models.CASCADE, null=True)
    motivo = models.TextField('Motivo de la consulta')
    antecedentes = models.TextField('Antecedentes de la enfermedad actual', blank=True, null=True)

serializers.py
class antecedenteSerializer(serializers.ModelSerializer):
    user = serializers.ReadOnlyField(source="user.username")

    class Meta:
        model = Antecedentes
        fields = ('paciente' ,'motivo', 'antecedentes', )

views.py
I was trying this but I'm not if this is correct or not
from historiaClinica import models as modelsHC
class antecedenteList(APIView):
    """
    Lista todos los antecedentes o crea uno nuevo
    """
    def get_object(self, pk):
        try:
            paciente = get_object_or_404(pk=pk)
            return modelsHC.Antecedentes.objects.get(paciente=paciente)
        except modelsHC.Antecedentes.DoesNotExist:
            raise Http404
    def get(self, request, pk, format=None):
        antecedente = self.get_object(pk)
        serializer = antecedenteSerializer(antecedente)
        return Response(serializer.data)

A:

If you need to show all Antecedentes related to the specific Paciente you can use reverse lookup paciente.antecedentes_set.all() so in view you can do this:
class antecedenteList(APIView):
    """
    Lista todos los antecedentes o crea uno nuevo
    """
    def get_object(self, pk):
        try:
            paciente = get_object_or_404(pk=pk)
            return paciente
        except modelsHC.Antecedentes.DoesNotExist:
            raise Http404
    def get(self, request, pk, format=None):
        paciente = self.get_object(pk)
        antecedentes = paciente.antecedentes_set.all()
        serializer = antecedenteSerializer(antecedentes, many=True)
        return Response(serializer.data)

Note I am using serializer's many=True argument to serialize multipe objects at the same time.
Also you may need in the future nested serialization to show all antecedentes in the paciente data. Details of nested serialization you can find here.

