accessing 2 foreign key fields at the same time in django serializers-CodePudding

I have the following models in my django rest framework project. in this project there are products and they have producers and importers.

# models.py
class Product(models.Model):
    name = models.CharField(max_length=255)
    producer = models.ManyToManyField(Company, related_name='producer')
    importer = models.ManyToManyField(Company, related_name='importer')

class Company(models.Model):
    name = models.CharField(max_length=255)

I need to make an API which retrieves an instance of the "Company" model and gives me a list of the products they have produced and another list for the products that they have imported

Now I know to do this with only one manytomany field, I can do the following:

class CompanyRetrieveSerializer(serializers.ModelSerializer):
    class ProductSerializer(serializers.ModelSerializer):
        class Meta:
            model = Product
            fields = ('name',)
    
    product_set = ProductSerializer(read_only=True, many=True,)
    class Meta:
        model = Company
        fields = '__all__'

but since there are two fields in the product model that reference the company model, this doesn't work. Is there any way to fix this issue?

CodePudding user response：

Tehe reason this does not work is because you specified related_name='producer': related_name is the name of the relation in reverse, so it makes not much sense to name this producer. You can rename the relations to:

class Product(models.Model):
    name = models.CharField(max_length=255)
    producer = models.ManyToManyField(Company, related_name='produced_products')
    importer = models.ManyToManyField(Company, related_name='imported_products')

then you can serialize the two relations with:

class CompanyRetrieveSerializer(serializers.ModelSerializer):
    class ProductSerializer(serializers.ModelSerializer):
        class Meta:
            model = Product
            fields = ('name',)
    
    produced_products = ProductSerializer(read_only=True, many=True)
    imported_products = ProductSerializer(read_only=True, many=True)
    
    class Meta:
        model = Company
        fields = '__all__'