Ruby Rails数据库关系 - 一对多

This is mainly a theoritical question, but just wanted to make sure that i'm doing it correctly. Consider a Ruby Rails project where there are two models, one being User and the other being Alliance.

这主要是一个理论问题，但只是想确保我正确地做到了。考虑一个Ruby Rails项目，其中有两个模型，一个是User，另一个是Alliance。

A user can only have one alliance. An alliance can have many users.

用户只能拥有一个联盟。联盟可以拥有许多用户。

That is very much simply a :has_many, :belongs_to relationship.

这非常简单：a：has_many，：belongs_to relationship。

However, i feel that using an intermediate model is a better way to do it. That would be a :has_many :through :users_alliances, where users_alliances would be an intermediate model.

但是，我觉得使用中间模型是一种更好的方法。那将是：has_many：through：users_alliances，其中users_alliances将是一个中间模型。

What do you think is the best way to do that ?

您认为最好的方法是什么？

2 个解决方案

#1

Don't use habtm, it doesn't make the join into a fully fledged model, which is what you need. Use has_many :through on the alliance side and has_one :through on the user side.

不要使用habtm，它不会使连接成为一个完全成熟的模型，这是你需要的。在联盟方使用has_many：through，在用户端使用has_one：through。

User
  has_one :alliance_membership
  has_one :alliance, :through => :alliance_membership

AllianceMembership
  belongs_to :user
  belongs_to :alliance

Alliance 
  has_many :alliance_memberships
  has_many :users, :through => :alliance_memberships

Personally i prefer the class name AllianceMembership to UserAlliance but you could use either. UsersAlliances is ugly though imo. (another advantage of has_many/one :through is that you can call the join table/class whatever you want).

我个人更喜欢班级名称AllianceMembership到UserAlliance，但你可以使用其中任何一个。用户联盟虽然是imo，但是很难看。（has_many / one的另一个优点：通过你可以随意调用连接表/类）。

This gives you the option to easily change to users having many alliances later on if you want.

这使您可以选择在以后轻松更改为具有多个联盟的用户。

#2

Why do you think that? What do you think you'll gain from the join model?

为什么你这么想？您认为从连接模型中获得什么？

Personally I doubt the extra table/model would be helpful, unless you think that one-to-many will become many-to-many in the future.

我个人怀疑额外的表/模型会有所帮助，除非你认为一对多将在未来成为多对多。

#1