rails 3 validation on uniqueness on multiple attributes

In Rails 2, I would have written:

validates_uniqueness_of :zipcode, :scope => :recorded_at

In Rails 3:

validates :zipcode, :uniqueness => {:scope => :recorded_at}

For multiple attributes:

validates :zipcode, :uniqueness => {:scope => [:recorded_at, :something_else]}

ruby-on-rails validation

Multiple Scope Parameters:

class TeacherSchedule < ActiveRecord::Base  validates_uniqueness_of :teacher_id, :scope => [:semester_id, :class_id]end

This should answer Greg's question.

ruby-on-rails validation

Dont work for me, need to put scope in plural

validates_uniqueness_of :teacher_id, :scopes => [:semester_id, :class_id]