Nested Serializers with multiple tables not working - django

Question

I have the below tables in models.py.
class ProductLine(models.Model):
availability = models.CharField(max_length=20, blank=True, null=True)
series = models.CharField(max_length=20, blank=True, null=True)
model = models.CharField(max_length=20, blank=True, null=True)
class Meta:
db_table = "product_line"
class DriveType(models.Model):
drive_name = models.CharField(max_length=20, blank=True, null=True)
product_line = models.ForeignKey(ProductLine, related_name="drive_type")
class Requirements(models.Model):
performance_unit = models.CharField(max_length=100, blank=True, null=True)
drive_type = models.OneToOneField(DriveType,on_delete=models.CASCADE,primary_key=True)
class Meta:
db_table = "requirements"
class WorkloadType(models.Model):
workload_type_options = models.CharField(max_length=50, blank=True, null=True)
drive_type = models.OneToOneField(DriveType,on_delete=models.CASCADE,primary_key=True)
class Meta:
db_table = "workload_type"
I have below serializers:
class WorkloadTypeSerializer(serializers.ModelSerializer):
class Meta:
model = WorkloadType
fields = "__all__"
class RequirementsSerializer(serializers.ModelSerializer):
class Meta:
model = Requirements
fields = "__all__"
class DriveTypeSerializer(serializers.ModelSerializer):
requirements = RequirementsSerializer(many = False, read_only = True)
workload_type = WorkloadTypeSerializer(many=False,read_only=True)
class Meta:
model = DriveType
fields = (
"drive_name", "available_drive_type", "capacity", "raid_type", "raid_size", "workload", "workload_percentage",
"raid_groups", "compression", "compression_value","requirements","workload_type")
class ProductLineSerializer(serializers.ModelSerializer):
drive_type = DriveTypeSerializer(many=True, read_only=True)
class Meta:
model = ProductLine
fields = ('availability','series','model','drive_type')
In my views I have this:
class SnippetDetail(generics.RetrieveUpdateDestroyAPIView):
def get_queryset(self):
return ProductLine.objects.filter(id=self.kwargs.get("pk"))
serializer_class = ProductLineSerializer
I am getting output as below :
{
"availability": "Current",
"series": "3000",
"model": "2000",
"drive_type": [
{
"drive_name": "drive1",
"requirements": {
"drive_type": 2,
"performance_unit": "by_iops",
}
}
]
}
Why I am not able to see WorkLoadType tables data in json where as I am able to see Requirements data . I don't even see the field in json. Nested serializers only support a single relation tables

Answer 1

Answering my own question. Have to use related_name in the models for reverse relationship.
class Requirements(models.Model):
performance_unit = models.CharField(max_length=100, blank=True, null=True)
drive_type = models.OneToOneField(DriveType,on_delete=models.CASCADE,primary_key=True,related_name=requirements)
class Meta:
db_table = "requirements"
class WorkloadType(models.Model):
workload_type_options = models.CharField(max_length=50, blank=True, null=True)
drive_type = models.OneToOneField(DriveType,on_delete=models.CASCADE,primary_key=True,related_name=workload_type)