夹具的Django自然键给出反序列化错误

问题描述

你需要

• natural_key在模型中定义方法
• 有get_by_natural_key方法的经理
• 实际附上经理（objects=GraphManager()）

在玩完您的代码后，我使它起作用：

class GraphTypeManager(models.Manager):
    def get_by_natural_key(self, type):
        return self.get(type=type)

class GraphType(models.Model):
    type = models.CharField(max_length=100, unique=True)
    objects = GraphTypeManager()

    def natural_key(self):
        return (self.type,)  # must return a tuple

class GraphManager(models.Manager):
    def get_by_natural_key(self, name):
        return self.get(name=name)

class Graph(models.Model):
    name = models.CharField(max_length=200, unique=True)
    type = models.ForeignKey(GraphType)
    objects = GraphManager()

转储数据：

$ bin/django dumpdata index --indent=4 --natural > project/apps/fixtures_dev/initial_data.json
[
    {
        "pk": 1,
        "model": "index.graphtype",
        "fields": {
            "type": "asotuh"
        }
    },
    {
        "pk": 1,
        "model": "index.graph",
        "fields": {
            "type": [
                "asotuh"
            ],
            "name": "saoneuht"
        }
    }
]

bin/django loaddata project/apps/fixtures_dev/initial_data.json 
Installed 2 object(s) from 1 fixture(s)

解决方法

我在SO上已经看到了一些与此类似的问题，但是似乎没有一个问题可以回答我的特定问题。我是Django的新手，正在按照此页面上的说明进行操作，以允许自己使用自然键加载固定装置。不过，我遇到了反序列化错误，因为Django想要一个外键为整数，并且似乎无法按照说明中的说明将我的自然键映射为一个整数主键。具体来说，我相关的模型代码是：

class GraphTypeManager(models.Manager):
    def get_by_natural_key(self,type):
        return self.get(type=type)
class GraphType(models.Model):
    type = models.CharField(max_length=100,unique=True)

class GraphManager(models.Manager):
    def get_by_natural_key(self,name):
        return self.get(name=name)
class Graph(models.Model):
    name = models.CharField(max_length=200,unique=True)
    type = models.ForeignKey(GraphType)

class LineManager(models.Manager):
    def get_by_natural_key(self,name):
        return self.get(name=name)
class Line(models.Model):
    name = models.CharField(max_length=200,unique=True)

class GraphToLineManager(models.Manager):
    def get_by_natural_key(self,line,graph):
        return self.get(line=line,graph=graph)
class GraphToLine(models.Model):
    line = models.ForeignKey(Line)
    graph = models.ForeignKey(Graph)
    class Meta:
        unique_together = (('line',"graph"),)

我的YAML固定装置是：

- model: graphs_container.GraphType
  pk: null
  fields:
    type: TimeSeries
- model: graphs_container.Graph
  pk: null
  fields:
    name: LikesOverTime
    type: [TimeSeries]
- model: graphs_container.Graph
  pk: null
  fields:
    name: UsersOverTime
    type: [TimeSeries]
- model: graphs_container.Line
  pk: null
  fields:
    name: NumUsers
- model: graphs_container.Line
  pk: null
  fields:
    name: NumLikes

但是，当尝试运行时python manage.py loaddata sample_data.yaml，出现以下错误：

DeserializationError: [u"'['TimeSeries']' value must be an integer."]

我究竟做错了什么？