Three levels of indirection

In the following hypothetical scenario, I’d like to associate Books
with Clubs without using finder_sql. Apparently, if you use
finder_sql, all the find_in_collection methods are not added to the
associated objects. Without which I won’t be able to call
my_club.books.find(:all, :conditions => ‘is_read = true’) or to do
pagination for example.

Class Club < ActiveRecord::Base
has_many :memberships
has_many :readers, :through => :memberships

        #DOES NOT WORK
        #has_many :books, :through => :readers

        #DOES NOT ADD find_in_collection METHODS
        #has_many :books, :finder_sql =>
        #          %q{
        #                      select distinct books.*
        #                      from books
        #                      join memberships on books.reader_id

= memberships.reader_id and memberships.club_id = #{}
# order by books.read_at desc
# }

Class Memberships < ActiveRecord::Base
belongs_to :club
belongs_to :reader

Class Reader < ActiveRecord::Base
has_many :memberships
has_many :books

Class Book < ActiveRecord::Base
belongs_to :reader

Does anyone have any idea how I can create this association without
rewriting the find_in_collection methods?


Perhaps I could write my own find method and extend the association
proxy? Is there a more elegant way?