CREATE TABLE captain (Captain_ID NUMBER, Name CLOB, Ship_ID NUMBER, age CLOB, Class CLOB, Rank CLOB)
CREATE TABLE Ship (Ship_ID NUMBER, Name CLOB, Type CLOB, Built_Year FLOAT, Class CLOB, Flag CLOB)

What is the average age of captains in different classes?, and order mean age in asc order.
SELECT Class, AVG(age) FROM captain GROUP BY Class ORDER BY AVG(age)
SELECT "Class", AVG("age") FROM "captain" GROUP BY "Class" ORDER BY AVG("age")