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rohittk239 rohittk239 - 9 months ago 49
JSON Question

Left Outer Join 2 models and return query in JSON

I am using DRF to serialize and have the api endpoints to display json data.

I have 2 models - 

class FooOne(models.Model):

  field_a = models.CharField(max_length=255, null=False)

  field_b = models.CharField(max_length=255, null=False)

  field_c = models.CharField(max_length=255, null=False)



class FooTwo(models.Model):

  field_fk = models.ForeignKey(FooOne)

  field_d = models.CharField(max_length=255, null=False)

  field_e = models.CharField(max_length=255, null=False)


these are my serializer classes -

class FooOneSerializer(serializers.ModelSerializer): 

    class Meta:

        model = FooOne

        fields = (field_a, field_b, field_c)



class FooTwoSerializer(serializers.ModelSerializer): 

      field_fk = FooOneSerializer()

      class Meta:

         model = FooTwo

         fields = (field_fk, field_d, field_e)


FooTwoSerializer
will return data with field_fk as a nested dictionary. What i want to is to return other fields of
FooOneSerialzer
that arent foreign key to
FooTwo
and append it the final rendered result of
FooTwoSerializer
.
How do i go about this?

Baterson Baterson
Answer

If I understand well, you want concatenate the results of FooOneSerailizer and all fields of FooTwoSerializer. You can do so by overriding to_represetation() method. 

class FooTwoSerializer(serializers.ModelSerializer): 

     class Meta:
         model = FooTwo
         fields = (field_d, field_e)

     def to_representation(self, instance):
         # get OrderedDict with original fields
         response = super(FooTwoSerializer, self).to_representation(instance)
         # get OrderedDict with foreign foo_one data
         foo_one = FooOneSerializer(instance.field_fk).data
         # set this fields to original data
         for key in foo_one:
             response[key] = foo_one[key]
         return response
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