Django rest框架-PrimaryKeyRelatedField

dowjones123 发表于 Dev

dowjones123

我正在关注Django REST框架教程，并且目前在这里：http : //www.django-rest-framework.org/tutorial/4-authentication-and-permissions#adding-endpoints-for-our-user -楷模

我的UserSerializer代码如下所示：

class UserSerializer(serializers.ModelSerializer):
    snippets = serializers.PrimaryKeyRelatedField(many=True, read_only=True)

    class Meta:
        model = User
        fields = ('id', 'username', 'snippets')

我试图确切地了解什么是PrimaryKeyRelatedField。为此，我正在按照以下方式更改代码并刷新URLhttp://127.0.0.1:8000/users/以查看不同的输出

变体1

snippets = serializers.RelatedField(many=True, read_only=True)


{
    "count": 1, 
    "next": null, 
    "previous": null, 
    "results": [
        {
            "id": 1, 
            "username": "som", 
            "snippets": [
                "Snippet title = hello", 
                "Snippet title = New2"
            ]
        }
    ]
}

这将打印出代码__unicode__()段的值。我期望这个

变体2-使用PrimaryKeyRelatedField

snippets = serializers.PrimaryKeyRelatedField(many=True, read_only=True)


{
    "count": 1, 
    "next": null, 
    "previous": null, 
    "results": [
        {
            "id": 1, 
            "username": "som", 
            "snippets": [
                1, 
                2
            ]
        }
    ]
}

这会打印出两个片段的主键ID-我不明白

变体3-注释掉也会产生

#snippets = serializers.PrimaryKeyRelatedField(many=True, read_only=True)

{
    "count": 1, 
    "next": null, 
    "previous": null, 
    "results": [
        {
            "id": 1, 
            "username": "som", 
            "snippets": [
                1, 
                2
            ]
        }
    ]
}