Retrieving a Foreign Key value with django-rest-framework serializers

Solution 1:

In the DRF version 3.6.3 this worked for me

class ItemSerializer(serializers.ModelSerializer):
    category_name = serializers.CharField(source='category.name')

    class Meta:
        model = Item
        fields = ('id', 'name', 'category_name')

More info can be found here: Serializer Fields core arguments

Solution 2:

Just use a related field without setting many=True.

Note that also because you want the output named category_name, but the actual field is category, you need to use the source argument on the serializer field.

The following should give you the output you need...

class ItemSerializer(serializers.ModelSerializer):
    category_name = serializers.RelatedField(source='category', read_only=True)

    class Meta:
        model = Item
        fields = ('id', 'name', 'category_name')

Solution 3:

Another thing you can do is to:

• create a property in your Item model that returns the category name and
• expose it as a ReadOnlyField.

Your model would look like this.

class Item(models.Model):
    name = models.CharField(max_length=100)
    category = models.ForeignKey(Category, related_name='items')

    def __unicode__(self):
        return self.name

    @property
    def category_name(self):
        return self.category.name

Your serializer would look like this. Note that the serializer will automatically get the value of the category_name model property by naming the field with the same name.

class ItemSerializer(serializers.ModelSerializer):
    category_name = serializers.ReadOnlyField()

    class Meta:
        model = Item