## lista.rb
class Lista < ActiveRecord::Base
  set_table_name "listas"

  validates_length_of :nome, :minimum=>4, :allow_nil => false, :message => ": Por favor, preencha o nome da lista maior que 4 caracteres."

  belongs_to :cliente, :class_name => "Cliente", :foreign_key => "id_cliente"

  def self.findBoth(conditions, order=:nome)
    @listasEstaticas = ListaEstatica.find(:all, :conditions=>conditions)
    @listasDinamicas = ListaDinamica.find(:all, :conditions=>conditions)

    # Getting the items
    @items = @listasEstaticas + @listasDinamicas

    # Resorting the items by name
    @items.sort_by {|lst| lst[order] }

    return @items
  end

end

## lista_estatica.rb
class ListaEstatica < Lista
    set_table_name "listas_estaticas" #:nodoc:

    belongs_to :cliente, :class_name => "Cliente", :foreign_key => "id_cliente"

    has_and_belongs_to_many :contatos, :class_name => "Contato", :join_table => "lista_estatica_contatos", :association_foreign_key => "id_contato", :foreign_key=>"id_lista_estatica", :uniq=>true #:nodoc:]

    def totalContatos
      contatos.length
    end

end

## the SQL of creation
CREATE TABLE listas
(
  nome varchar(30),
  "type" varchar(20),
  id int8 NOT NULL,
  CONSTRAINT pk_lista PRIMARY KEY (id)
)
WITHOUT OIDS;
CREATE TABLE listas_estaticas
(
  id int8 NOT NULL DEFAULT nextval('sq_listas_estaticas'::regclass),
  id_cliente int8 NOT NULL,
  descricao text,
  id_lista int8,
  CONSTRAINT pk_listas_estaticas PRIMARY KEY (id),
  CONSTRAINT fk_listas_estaticas_cliente FOREIGN KEY (id_cliente)
      REFERENCES clientes (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE,
  CONSTRAINT fk_listas_estaticas_is_a_lista FOREIGN KEY (id_lista)
      REFERENCES listas (id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE
)
WITH OIDS;