# File lib/active_record/connection_adapters/postgresql_adapter.rb, line 323
      def unescape_bytea(original_value)
        # In each case, check if the value actually is escaped PostgreSQL bytea output
        # or an unescaped Active Record attribute that was just written.
        if @connection.respond_to?(:unescape_bytea)
          self.class.instance_eval do
            define_method(:unescape_bytea) do |value|
              @connection.unescape_bytea(value) if value
            end
          end
        elsif PGconn.respond_to?(:unescape_bytea)
          self.class.instance_eval do
            define_method(:unescape_bytea) do |value|
              PGconn.unescape_bytea(value) if value
            end
          end
        else
          raise 'Your PostgreSQL connection does not support unescape_bytea. Try upgrading to pg 0.9.0 or later.'
        end
        unescape_bytea(original_value)
      end