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PORuby On Rails multiple composite primary keys question
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  1. PORuby On Rails multiple composite primary keys question
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    copied!<p>I am a new guy in Ruby, and I have tables with these primary keys:</p> <ol> <li><strong>transaction_types:</strong> <ul> <li>transaction_type</li> </ul></li> <li><strong>transaction_headers:</strong> <ul> <li>transaction_type</li> <li>transaction_year</li> <li>transaction_id</li> </ul></li> <li><strong>transaction_details:</strong> <ul> <li>transaction_type</li> <li>transaction_year</li> <li>transaction_id</li> <li>city_id</li> <li>ticker_id</li> </ul></li> <li><strong>tickers:</strong> <ul> <li>city_id</li> <li>ticker_id</li> </ul></li> </ol> <p>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.</p> <p>These are my models:</p> <pre><code>#models class transaction_type &lt; ActiveRecord::Base has_many :transaction_headers, :foreign_key=&gt;'transaction_type' has_many :transaction_details, :foreign_key=&gt;'transaction_type' has_many :tickers, :through=&gt;:transaction_details end class transaction_header &lt; ActiveRecord::Base belongs_to: transaction_types, :foreign_key=&gt;'transaction_type' has_many :transaction_details has_many :tickers, :through=&gt;:transaction_details end class transaction_detail &lt; ActiveRecord::Base belongs_to: transaction_headers has_many :tickers end class ticker &lt; ActiveRecord::Base end </code></pre> <p>I need to perform a relationship to each correspond primary keys.. It was easy for <strong>transaction_type</strong> to <strong>transaction_detail</strong> and <strong>transaction_header</strong>, but how do I create an association between <strong>transaction_header</strong> and <strong>transaction_detail</strong>, and also between <strong>transaction_detail</strong> and <strong>ticker</strong>? How to create the :through keys for <strong>tickers</strong> relationships?</p> <p>Thank you</p>
 

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