在Django中加载具有多对一关系的夹具

Question

djangoproject.com上的Django教程给出了这样的模型:

import datetime
from django.utils import timezone
from django.db import models

class Poll(models.Model):
    question = models.CharField(max_length = 200)
    pub_date = models.DateTimeField('date published')

    def __unicode__(self):
        return self.question

    def was_published_recently(self):
        now = timezone.now()
        return now - datetime.timedelta(days = 1) <= self.pub_date < now

    was_published_recently.admin_order_field = 'pub_date'
    was_published_recently.boolean = True
    was_published_recently.short_description = 'Published recently?'

class Choice(models.Model):
    poll = models.ForeignKey(Poll)
    choice_text = models.CharField(max_length = 200)
    votes = models.IntegerField(default = 0)

    def __unicode__(self):
        return self.choice_text

Choice使用ForeignKey,这是一种多对一的关系,所以我应该能够使用一个选择进行多个轮询.如果我尝试从夹具中加载它,如下所示:

[
    {
        "model": "polls.Poll",
        "pk": 3,
        "fields": {
            "question": "What time do you sleep?",
            "pub_date": "2013-07-29T10:00:00+00:00"
        }
    },
    {
        "model": "polls.Poll",
        "pk": 4,
        "fields": {
            "question": "What time do you get up?",
            "pub_date": "2013-07-29T10:00:00+00:00"
        }
    },
    {
        "model": "polls.Choice",
        "pk": 4,
        "fields": {
            "poll": [{"pk": 3}, {"pk": 4}],
            "choice_text": "10:00",
            "votes": 0
        }
    }
]

我收到此错误:

    DeserializationError: Problem installing fixture '/.../poll/polls/fixtures/initial_data.json': [u"'[{u'pk': 3}, {u'pk': 4}]' value must be an integer."]

或者:

{
        "model": "polls.Choice",
        "pk": 4,
        "fields": {
            "poll": [3, 4],
            "choice_text": "10:00",
            "votes": 0
        }
    }

我收到此错误:

DeserializationError: Problem installing fixture '/.../poll/polls/fixtures/initial_data.json': [u"'[3, 4]' value must be an integer."]

如何从夹具中加载多对一关系？

Answer 1

这是教程中的引用：

最后，请注意使用ForeignKey 定义了一个关系。这告诉 Django 每个 Choice 都与一个 Poll 相关。Django 支持所有常见的数据库关系：多对一、多对多和一对一。

每个都Choice与一个相关Poll，并且您正在尝试将键列表传递到该Choice.poll字段。

但是，每个民意调查都可能与多个选择相关：

{
    "pk": 4, 
    "model": "polls.Choice", 
    "fields": {
        "votes": 0, 
        "poll": 2, 
        "choice_text": "Meh."
    }
}, 
{
    "pk": 5, 
    "model": "polls.Choice", 
    "fields": {
        "votes": 0, 
        "poll": 2, 
        "choice_text": "Not so good."
    }
}

希望有帮助。