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

Return the name of the youngest captain.
SELECT name FROM captain ORDER BY age LIMIT 1
SELECT "name" FROM "captain" ORDER BY "age" NULLS FIRST LIMIT 1