Django中的这些模型之间的关系 [英] Relationships among these models in Django

问题描述

我想建立一个网站：

• 有一组10张卡



• 每个用户选择哪个卡是重要的，不重要的（来自同一组10张卡）


• 他的选择被保存并链接到他的帐户。

• there is a set of 10 Cards
• on each Card, there are Important/Not_Important/Unknown attributes
• each User chooses which card are important and not important (from the same set of 10 Cards)
• his choices are saved and linked to his account.

我已经提出了这样的模式：

I have come up with models like these:

1. 用户：我使用 django.contrib.auth.models.User



2. 卡：

1. User: I use django.contrib.auth.models.User

2. Card:

class Card(models.Model):
    is_important = models.NullBooleanField(default=None)

CardSet：

CardSet:

class CardSet(models.Model):

    cards = models.ManyToManyField(Card)

    user = models.ForeignKey(User,related_name='card_set')

对我而言，这个数据库的关系是显而易见的，因为我没有知道如何检索用户实例决定重要/不重要/未知的卡片列表。但是，我不知道如何把它们放在正确的关系中。

It is obvious to me this database relationship has something wrong because, I don't know how to retrieve a list of cards that an instance of User has decided to be important/not important/unknown. However, I don't know how to put them in right relationship.

推荐答案

我想我已经找到了我的问题的解决方案：
模型将如下所示：

I guess I have found the solution to my question: The models would be like this :

class Card(models.Model):
    card_number = models.IntegerField(unique=True)
    content = models.TextField(null=False)

class Choice(models.Model):
    user = models.ForeignKey(User)
    card = models.ForeignKey(Card)
    is_important = models.NullBooleanField(default=None)

    class Meta:
        unique_together = ('user','card')

答案的关键是使用 unique_together 元选项。

The key to the answer is to use unique_together Meta option.

请查看我的解决方案，如果您有更好的解决方案或任何其他解决方案，请随时提出建议。我可以从你那里学到很多东西。

Please review my solution and if you have a better solution or any alternative solution, please feel free to suggest. I can learn a lot from yours.

谢谢！

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