CREATE TABLE captain (captain_id DECIMAL, name TEXT, ship_id DECIMAL, age TEXT, class TEXT, rank TEXT)
CREATE TABLE ship (ship_id DECIMAL, name TEXT, type TEXT, built_year DECIMAL, class TEXT, flag TEXT)

List all ship names in the order of built year and class.
SELECT name FROM ship ORDER BY built_year, class
SELECT "name" FROM "ship" ORDER BY "built_year" NULLS FIRST, "class" NULLS FIRST