django - 如何在序列化程序中获取序列化程序字段值

Question

我有这个 ModelSerializer:

class BidSerializer(serializers.ModelSerializer):

    class Meta:
        model = Bid
        fields = '__all__'

    def validate_amount(self, value):
        auction = Auction.objects.get(id=self.validated_data['auction'])
        if auction.price_step % value:
            raise serializers.ValidationError()

但它抛出“is_valid() should be called”异常。如何正确访问拍卖字段值？

Answer 1

如果你想根据另一个字段的值检查一个字段，你应该使用 object-level-validation

class BidSerializer(serializers.ModelSerializer):

    class Meta:
        model = Bid
        fields = '__all__'

    def validate(self, data):
        auction = Auction.objects.get(id=data['auction'])
        amount = data.get('amount')
        if auction.price_step % amount:
            msg = {'amount' : ['this field is not valid']}
            raise serializers.ValidationError(msg)