named scopes I am using

programs.rb

  scope :open, lambda {
    joins(:program_populations).
    where('program_populations.current_population < program_populations.max_population').
    group("programs.id")
  }
  scope :closed, lambda {
    joins(:program_populations).
    where('program_populations.current_population >= program_populations.max_population').
    group("programs.id")
  }