How do I set up a :through ActiveRecord association in Ruby On Rails?

Question

I am having trouble figuring out associations. I need to link up a User to Feedback through Transactions. Feedback has transaction_id property and Transaction has seller_id. How would I do that using associations? Here is what I have so far, appreciate your help! Thanks!

class Feedback < ActiveRecord::Base
     belongs_to :user
end

class User < ActiveRecord::Base
    has_many :feedbacks
end

class Transaction < ActiveRecord::Base
    belongs_to :seller, :class_name => 'User', :foreign_key => 'seller_id'
end

Answer 1

User -> Transactions -> Feedback

class User < ActiveRecord::Base
    has_many :transactions
    has_many :feedbacks, through: :transactions, foreign_key: 'seller_id'
end

class Transaction < ActiveRecord::Base
    has_many :feedback
    belongs_to :seller, class_name: 'User', foreign_key: 'seller_id'
end

class Feedback < ActiveRecord::Base
     belongs_to :transaction
end