Ruby on Rails的多元复合主键的问题 [英] Ruby On Rails multiple composite primary keys question

问题描述

我在Ruby的一个新的家伙，我与这些主键的表：

I am a new guy in Ruby, and I have tables with these primary keys:

1. transaction_types：
   
   • transaction_type

1. transaction_types:
   
   • transaction_type

• transaction_type
• transaction_year
• 的transaction_id

• transaction_type
• transaction_year
• 的transaction_id
• city_id
• ticker_id

• city_id
• ticker_id

当然，这些模型具有其他非主键如CUSTOMER_ID，CONNECTION_ID或日期，或USER_ID等，但这些都不是对关系很重要，因为这些仅仅是数据或我没有与这些任何问题。

Of course, those models have other non primary keys such as customer_id, connection_id or date, or user_id, etc, but those are not important for relationships, as those are merely data or I don't have any problem with those.

这些都是我的模型：

#models  

class transaction_type < ActiveRecord::Base  
  has_many :transaction_headers, :foreign_key=>'transaction_type'  
  has_many :transaction_details, :foreign_key=>'transaction_type'
  has_many :tickers, :through=>:transaction_details
end

class transaction_header < ActiveRecord::Base  
  belongs_to: transaction_types, :foreign_key=>'transaction_type'
  has_many :transaction_details
  has_many :tickers, :through=>:transaction_details
end

class transaction_detail < ActiveRecord::Base
  belongs_to: transaction_headers
  has_many :tickers
end

class ticker < ActiveRecord::Base

end

我需要执行一个关系到每个对应的主键。它是容易的 transaction_type 为 transaction_detail 和 transaction_header ，但怎么办我创造之间的关联 transaction_header 和 transaction_detail ，也与 transaction_detail 和股票？如何创建的：通过对行情关系

I need to perform a relationship to each correspond primary keys.. It was easy for transaction_type to transaction_detail and transaction_header, but how do I create an association between transaction_header and transaction_detail, and also between transaction_detail and ticker? How to create the :through keys for tickers relationships?

感谢您

推荐答案

ActiveRecord的不支持复合主键开箱即用，但这个插件应该去：

ActiveRecord does not support composite primary keys out of the box, but this plugin should going:

http://compositekeys.rubyforge.org/

他们对如何开始一个很好的指南。

They have a nice guide on how to get started.

希望这有助于！

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