app/models/upcoming.rb
# == Schema Information
#
# Table name: upcomings
#
# id :integer not null, primary key
# title :string(255)
# date :datetime
# description :string(255)
# url :string(255)
# created_at :datetime
# updated_at :datetime
#
class Upcoming < ActiveRecord::Base
validates_uniqueness_of :url
end