any_of.rb

# Add this to an initializer file to extend ActiveRecord
# You can pass in an array of hashes.  The key/values of your hashes will be joined w/ ANDs
# The hashes in the array will be joined w/ ORs
# You can also pass in an array of strings or arrays

class ActiveRecord::Base
  def self.any_of( queries )
    queries = queries.map do |query|
      query = where( query ) if [ String, Hash ].any? { |type| query.kind_of? type }
      query = where( *query ) if query.kind_of?( Array )
      query.arel.constraints.reduce( :and )
    end

    where( queries.reduce( :or ) )
  end
end