Django REST Framework中的外键值

Question

models.py:

class Station(models.Model):
    station = models.CharField()

class Flat(models.Model):
    station = models.ForeignKey(Station, related_name="metro")
    # another fields

然后在serializers.py中:

class StationSerializer(serializers.ModelSerializer):
    station = serializers.RelatedField(read_only=True)

    class Meta:
        model = Station


class FlatSerializer(serializers.ModelSerializer):
    station_name = serializers.RelatedField(source='station', read_only=True)

    class Meta:
        model = Flat
        fields = ('station_name',)

我有一个错误:

NotImplementedError:RelatedField.to_representation()必须实现.如果要从REST框架版本2升级,则可能需要ReadOnlyField.
我看了这个,但它对我没有帮助.
如何解决？
谢谢!

Answer 1

RelatedField是处理关系的所有字段的基类.通常您不应该使用它,除非您将其子类化为自定义字段.

在您的情况下,您甚至根本不需要相关字段.您只需要查找只读的单个外键表示,因此您只需使用CharField.

class StationSerializer(serializers.ModelSerializer):
    station = serializers.CharField(read_only=True)

    class Meta:
        model = Station


class FlatSerializer(serializers.ModelSerializer):
    station_name = serializers.CharField(source='station.name', read_only=True)

    class Meta:
        model = Flat
        fields = ('station_name', )

你似乎也想要你name的Station对象FlatSerializer.你应该source指向确切的字段,所以我station.name为你更新了它.