轨道多态模型实现 [英] rails polymorphic model implementation

问题描述

在我的项目，我有一个关系模式，允许用户按照对方。

In my project, I have a relationship model that allow users to follow each other.

class Relationship < ActiveRecord::Base
  attr_accessible :followed_id

  belongs_to :follower, :class_name => "User"
  belongs_to :followed, :class_name => "User"

end

现在，我想还允许用户按照课程和团体。难道我开始一个新的followedCourse和followedGroup模型或让我的关系模型的多态？我怎么做？谢谢。

Now, I want to also allow users to follow courses and groups. Do I start a new followedCourse and followedGroup model or do I make the relationship model polymorphic? How do I do that? Thanks.

推荐答案

我不会用多态的可能，大表。我认为最好的方法是使用 has_​​and_belongs_to_many 关系的这种关系。

I wouldn't use polymorphic for potentially-large tables. I think the best way to go is to use has_and_belongs_to_many relationships for this kind of relation.

记住要创建索引的USER_ID，GROUP_ID的东西加快一点。你可以通过使用 add_index（：TABLE_NAME，[：USER_ID，：GROUP_ID]）。

Remember to create indexes on user_id, group_id to speed up things a bit. You can do that by using add_index(:table_name,[:user_id,:group_id]).

我也做了独特的关系，你可以不追加：唯一=＆GT;真正的在 add_index 命令结束。

I would also make the relation UNIQUE, which you can do appending :unique => true at the end of the add_index command.

这篇关于轨道多态模型实现的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！