Question

您如何对出版物（文章，书籍，章节等）的引用和引用进行建模？

出版物可以是文章，书籍或章节，它有许多参考其他出版物和其他出版物参考它（称这些引用）

我需要能够列出出版物之间的关系：出版物中的参考文献以及其他出版物对本出版物的引用

我最初的理解是，这将是处理不同类型的出版物的多态关系，并且需要双向自身加入。

我刺伤了它

Publication
belongs_to :writing, :polymorphic =>true
has_and_belongs_to_many :references 
   :class_name => "Publication"
   :join_table => 'reference_citation' 
   :foreign_key => 'reference_id'
   :foreign_key => 'citation_id'

Book,    Chapter,    Article all have:
has_many :publications :as =>writing

我发现这有点令人困惑，所以任何有助于澄清它的建议都会很棒。甚至是对象和字段命名建议。

[我问过这个问题的不太清楚的版本here。]

我也可能需要使用很多通过因为我需要能够破坏关系

Answer 1

这是使用单表继承使用自引用关系的解决方案。使用以下命令创建应用程序：

$ rails myproject
$ cd myproject
$ script/generate model publication type:string name:string
$ script/generate model citation publication_id:integer reference_id:integer

以这种方式设置关系：

class Publication < ActiveRecord::Base
  has_many :citations
  has_many :cited_publications, :through => :citations, :source => :reference
  has_many :references, :foreign_key => "reference_id", :class_name => "Citation"
  has_many :refered_publications, :through => :references, :source => :publication
end

class Citation < ActiveRecord::Base
  belongs_to :publication
  belongs_to :reference, :class_name => "Publication"
end

class Article < Publication
end

class Book < Publication
end

class Chapter < Publication
end

现在我们可以创建数据库并从控制台中试用它：

$ rake db:migrate
$ script/console 
Loading development environment (Rails 2.2.2)
>> a = Article.create!(:name => "Article")
=> #<Article id: 1, ...>
>> b = Book.create!(:name => "Book")
=> #<Book id: 2, ...>
>> a.citations.create(:reference => b)
=> #<Citation id: 1, publication_id: 1, reference_id: 2, created_at: "2009-02-15 14:13:15", updated_at: "2009-02-15 14:13:15">
>> a.citations
=> [#<Citation id: 1, ...>]
>> a.references
=> []
>> b.citations
=> []
>> b.references
=> [#<Citation id: 1, publication_id: 1, reference_id: 2, created_at: "2009-02-15 14:13:15", updated_at: "2009-02-15 14:13:15">]    
>> a.cited_publications
=> [#<Book id: 2, type: "Book", name: "Book", created_at: "2009-02-15 14:11:00", updated_at: "2009-02-15 14:11:00">]
>> a.refered_publications
=> []
>> b.cited_publications
=> []
>> b.refered_publications
=> [#<Article id: 1, type: "Article", name: "Article", created_at: "2009-02-15 14:10:51", updated_at: "2009-02-15 14:10:51">]

Answer 2

这是一个不对出版物使用单表继承的解决方案。这意味着有文章，书籍和章节表，而不是一个出版物表。以下是运行以创建应用程序的命令：

$ rails myproject
$ cd myproject
$ script/generate model book name:string
$ script/generate model chapter name:string
$ script/generate model article name:string
$ script/generate model citation publication_type:string publication_id:integer reference_type:string reference_id:integer

在lib/acts_as_publication.rb：

中创建此文件

module ActsAsPublication
  def self.included(base)
    base.extend(ClassMethods)
  end
  module ClassMethods
    def acts_as_publication
      has_many :citations, :as => :publication
      has_many :references, :as => :reference, :class_name => "Citation"      
    end
  end
end

在config/initializers/acts_as_publication.rb：

中创建此文件

ActiveRecord::Base.send(:include, ActsAsPublication)

然后在每个模型，文章，书和章中调用，如下所示：

class Article < ActiveRecord::Base
  acts_as_publication
end

然后在app/models/citation.rb：

中添加这些关系

class Citation < ActiveRecord::Base
  belongs_to :publication, :polymorphic => true
  belongs_to :reference, :polymorphic => true
end

现在我们可以创建数据库并从控制台中试用它：

$ rake db:migrate
$ script/console 
Loading development environment (Rails 2.2.2)
>> a = Article.create!(:name => "a")
=> #<Article id: 1, ...>
>> b = Article.create!(:name => "b")
=> #<Article id: 2, ...>
>> Citation.create!(:publication => a, :reference => b)
=> #<Citation id: 1, publication_type: "Article", publication_id: 1, reference_type: "Article", reference_id: 2, created_at: "2009-02-15 13:14:27", updated_at: "2009-02-15 13:14:27">
>> a.citations
=> [#<Citation id: 1, ...>]
>> a.references
=> []
>> b.citations
=> []
>> b.references
=> [#<Citation id: 1, ...>]
>> Book.create!(:name => "foo")
=> #<Book id: 1, name: "foo", created_at: "2009-02-15 13:18:23", updated_at: "2009-02-15 13:18:23">
>> a.citations.create(:reference => Book.first)
=> #<Citation id: 2, publication_type: "Article", publication_id: 1, reference_type: "Book", reference_id: 1, created_at: "2009-02-15 13:18:52", updated_at: "2009-02-15 13:18:52">
>> Book.first.references
=> [#<Citation id: 2, ...>]
>> a.citations
=> [#<Citation id: 1, publication_type: "Article", publication_id: 1, reference_type: "Article", reference_id: 2, created_at: "2009-02-15 13:14:27", updated_at: "2009-02-15 13:14:27">, #<Citation id: 2, publication_type: "Article", publication_id: 1, reference_type: "Book", reference_id: 1, created_at: "2009-02-15 13:18:52", updated_at: "2009-02-15 13:18:52">]

Answer 3

我在http://github.com/francois/so-536261/tree/master

处的回答不完整

基本上，DB模式确实支持您的用例，但ActiveRecord不支持。该解决方案可能涉及使用find或sql或其他技巧。

棘手的活跃记录关系 - 多态双向自我指涉

3 个答案: