Adapted raw_sql to do typing.

raw_sql.rb

class RawSQL
  include ActiveRecord::ConnectionAdapters::Quoting

  def initialize(filename)
    @filename = filename
  end

  def result(params)
    pg = ActiveRecord::Base.connection
    @type_map ||= PG::BasicTypeMapForResults.new(pg.raw_connection)
    res = pg.execute(query % quoted_parameters(params))
    res.type_map = @type_map #http://stackoverflow.com/questions/25331778/getting-typed-results-from-activerecord-raw-sql/30948357
    res
  end

  private

  attr_reader :filename

  def query
    Rails.root.join('lib', 'sql', filename).read
  end

  def quoted_parameters(params)
    params.each_with_object({}) do |(key, value), result|
      result[key] =
          if value.is_a?(Array)
            value.map { |item| quote(item) }.join(', ')
          elsif value.is_a?(Integer)
            value
          else
            quote(value)
          end
    end
  end
end