Relational problem

the thing

The problem is this:

class Cmr < ActiveRecord::Base
  belongs_to :ruta
  ...
end
class Cmr24 < Cmr
  ...
end
class Ruta < ActiveRecord::Base
  has_many :cmrs, :dependent => :nullify
  ...
end

ruby-1.9.2-p0 > @cmr = Cmr.first
  Cmr Load (0.1ms)  SELECT `cmrs`.* FROM `cmrs` LIMIT 1
 => #<Cmr24 id: 633, codigo: "C1060", cmr_type: nil, direccion: "Maipu 1685", status: 1, ruta_id: 22, type: "Cmr24", zona: nil> 
ruby-1.9.2-p0 > @cmr.ruta
Mysql2::Error: Table 'eco_development.ruta' doesn't exist: SHOW FIELDS FROM `ruta` .....