ActiveRecord::QueryMethods#all!

all_or_nothing.gemspec

Gem::Specification.new do |gem|
  gem.name          = "all_or_nothing"
  gem.version       = '0.0.1'
  gem.authors       = ["Tatsuro Baba"]
  gem.email         = ["harakirisoul@gmail.com"]
  gem.description   = %q{TODO: Write a gem description}
  gem.summary       = %q{TODO: Write a gem summary}
  gem.homepage      = "https://gist.github.com/4543857"

  gem.files         = ['all_or_nothing.rb']
  gem.require_path  = '.'
end

all_or_nothing.rb

module ActiveRecord
  module QueryMethods
    def all_or_nothing!
      relation = clone
      result = relation.all
      if result.blank?
        raise ActiveRecord::RecordNotFound
      else
        result
      end
    end
  end
end

This method returns ActiveRecord::RecordNotFound exception if result of this relation is empty.