serialize multiple related models - django-models

Question

I am just learning django and rest-framework.
I have three models User, UserHospital and Timeslots. User is having time schedule for hospitals. I am requesting for users all details with related hospitals which displays hospital details along with timeslots. Want to represent user details in below format.
Whats wrong in my code?
Using viewsets and serializers it can be possible or i have to try another way?
{
"first_name": "abc",
"last_name": "xyz",
"mobile_number":1111111111,
"related_hospitals": [{
"id": 1,
"name": "bbbb"
"timeslot": [
{
"day": "TUE",
"start_time": "09:00:00",
"end_time": "15:00:00"
},
{
"day": "WED",
"start_time": "10:00:00",
"end_time": "20:00:00"
}
]
},
{
"id": 2,
"name": "ccc"
"timeslot": []
}]
}
created Models as below :
class Users(models.Model):
mobile_number = models.BigIntegerField()
first_name = models.CharField(max_length=255, null=True)
last_name = models.CharField(max_length=255, null=True)
class TimeSlots(BaseAbstract):
DAYS = (
('SUN', 'sunday'),
('MON', 'Monday'),
('TUE', 'tuesday'),
('WED', 'wednesday'),
('THU', 'thursday'),
('FRI', 'friday'),
('SAT', 'saturday'),
)
STATUS = (
(1, 'HOLIDAY'),
(2, 'ON_LEAVE'),
(3, 'AVAILABLE'),
(4, 'NOT_AVAILABLE')
)
DEFAULT_STATUS = 3
DEFAULT_DAY = "SUN"
day = models.CharField(default=DEFAULT_DAY, choices=DAYS, max_length=20)
start_time = models.TimeField()
end_time = models.TimeField()
status = models.SmallIntegerField(default=DEFAULT_STATUS, choices=STATUS)
class UserHospital(BaseAbstract):
user = models.ForeignKey('users.Users', on_delete=models.SET_NULL, null=True)
name = models.(Hospital,CharField(max_length=255, null=True)
timeslots = models.ManyToManyField(TimeSlots)
I have tried:
class TimeslotSerializer(serializers.ModelSerializer):
class Meta:
model = TimeSlots
fields = ('day', 'start_time', 'end_time')
read_only_fields = ('id',)
class RelatedHospitalSerializer(serializers.ModelSerializer):
timeslot = TimeslotSerializer(many=True)
class Meta:
model = UserHospital
fields = ('name', 'timeslot')
read_only_fields = ('id',)
class UserDetailsSerializer(serializers.ModelSerializer):
related_hospitals = serializers.SerializerMethodField()
def get_related_hospitals(self, obj):
hospitalData = []
if UserHospital.objects.all().filter(user=obj).exists():
hospitalData = UserHospital.objects.all().filter(user=obj)
return RelatedHospitalSerializer(hospitalData).data
class Meta:
model = Users
fields = ('first_name', 'last_name','mobile_number','related_hospitals')
read_only_fields = ('id', 'related_hospitals')
class UserDetailsViewset(mixins.CreateModelMixin, mixins.RetrieveModelMixin, mixins.ListModelMixin, viewsets.GenericViewSet):
queryset = Users.objects.all()
serializer_class = UserDetailsSerializer
def get_queryset(self):
userid = self.request.query_params.get('userid')
if userid is not None:
userData = Users.objects.filter(user=userid)
return userData
else:
return Users.objects.all()
whats wrong with my code ?

Answer 1

I would recommend using related_name parameter of models.ForeignKey, ..ManytoMany field etc
For example,
def Hospital(models.Model):
user = models.ForeignKey(....., related_name="hospitals")
...
def HospitalSerializer(models.Model):
...
def UserSerializer(Hyperlinkedmodelserializer ...(or other):
hospitals = HospitalSerializer(many=True)
class Meta:
....
Note: The use of "hospitals" ....
This will automatically allow one to get the result of a
UserSerializer(userModel, context={'request':request}).data ...
in your desired format