Getting Error while trying to get the value of the many to many field in django-CodePudding

models.py

class Organisation(models.Model):
    """
    Organisation model
    """
    org_id = models.AutoField(unique=True, primary_key=True)
    org_name = models.CharField(max_length=100)
    org_code = models.CharField(max_length=20)
    org_mail_id = models.EmailField(max_length=100)
    org_phone_number = models.CharField(max_length=20)
    org_address = models.JSONField(max_length=500, null=True)
    product = models.ManyToManyField(Product, related_name='products')
    org_logo = models.ImageField(upload_to='org_logo/')
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "organisation_master"

    def __str__(self):
        return self.org_name

serializers.py

class Organisation_Serializers(serializers.ModelSerializer):
    product_name = serializers.CharField(source='product.product_name')
    class Meta:
        model = Organisation
        fields = ('org_id', 'org_name', 'org_address', 'org_phone_number', 'org_mail_id','org_logo','org_code','product','product_name')

While i tried to get the value of the product name iam getting an error as "Got AttributeError when attempting to get a value for field product_name on serializer Organisation_Serializers. The serializer field might be named incorrectly and not match any attribute or key on the Organisation instance. Original exception text was: 'ManyRelatedManager' object has no attribute 'product_name'.

Can you please help me to fix this issue.Posting the traceback error.

Request Method: GET
Request URL:    http://127.0.0.1:8000/api/onboarding/organisation/
Django Version: 3.2.12
Exception Type: AttributeError
Exception Value:    
Got AttributeError when attempting to get a value for field `product_name` on serializer `Organisation_Serializers`.
The serializer field might be named incorrectly and not match any attribute or key on the `Organisation` instance.
Original exception text was: 'ManyRelatedManager' object has no attribute 'product_name'.
Exception Location: C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\fields.py, line 490, in get_attribute
Python Executable:  C:\Users\gobs4\AppData\Local\Programs\Python\Python310\python.exe
Python Version: 3.10.4
Python Path:    
['F:\\icaniotimesheet\\microservices',
 'C:\\Users\\gobs4\\AppData\\Local\\Programs\\Python\\Python310\\python310.zip',
 'C:\\Users\\gobs4\\AppData\\Local\\Programs\\Python\\Python310\\DLLs',
 'C:\\Users\\gobs4\\AppData\\Local\\Programs\\Python\\Python310\\lib',
 'C:\\Users\\gobs4\\AppData\\Local\\Programs\\Python\\Python310',
 'C:\\Users\\gobs4\\AppData\\Local\\Programs\\Python\\Python310\\lib\\site-packages']
Server time:    Thu, 21 Apr 2022 03:28:46  0000
Traceback Switch to copy-and-paste view
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\fields.py, line 457, in get_attribute
            return get_attribute(instance, self.source_attrs) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\fields.py, line 97, in get_attribute
                instance = getattr(instance, attr) …
▶ Local vars
During handling of the above exception ('ManyRelatedManager' object has no attribute 'product_name'), another exception occurred:
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\django\core\handlers\exception.py, line 47, in inner
                response = get_response(request) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\django\core\handlers\base.py, line 181, in _get_response
                response = wrapped_callback(request, *callback_args, **callback_kwargs) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\django\views\decorators\csrf.py, line 54, in wrapped_view
        return view_func(*args, **kwargs) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\viewsets.py, line 125, in view
            return self.dispatch(request, *args, **kwargs) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\views.py, line 509, in dispatch
            response = self.handle_exception(exc) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\views.py, line 469, in handle_exception
            self.raise_uncaught_exception(exc) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\views.py, line 480, in raise_uncaught_exception
        raise exc …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\views.py, line 506, in dispatch
            response = handler(request, *args, **kwargs) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\mixins.py, line 46, in list
        return Response(serializer.data) …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\serializers.py, line 768, in data
        ret = super().data …
▶ Local vars
C:\Users\gobs4\AppData\Local\Programs\Python\Python310\lib\site-packages\rest_framework\serializers.py, line 253, in data
                self._data = self.to_representation(self.instance)

CodePudding user response：

the many-to-many field cannot be serialized to charfield

product_name = serializers.CharField(source='product.product_name')

insead try the solution below Django rest framework serializing many to many field

CodePudding user response：

First, create the Product Serializer in: ProductSerializer(serializers.Serializer): product = serializers.CharField(max_length=100)

class Organisation_Serializers(serializers.ModelSerializer):
product_name =  ProductSerializer(many=True)
class Meta:
    model = Organisation
    fields = ('org_id', 'org_name', 'org_address', 'org_phone_number', 'org_mail_id','org_logo','org_code','product','product_name')