text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE train (ObjectNumber VARCHAR, Railway_ID VARCHAR); CREATE TABLE railway (ObjectNumber VARCHAR, Railway_ID VARCHAR)
  ### Question:
  List the object number of railways that do not have any trains.
  ### Answer:
  SELECT ObjectNumber FROM railway WHERE NOT Railway_ID IN (SELECT Railway_ID FROM train)