CREATE TABLE ship (Ship_ID INT, Name TEXT, Type TEXT, Nationality TEXT, Tonnage INT)
CREATE TABLE mission (Mission_ID INT, Ship_ID INT, Code TEXT, Launched_Year INT, Location TEXT, Speed_knots INT, Fate TEXT)

For each type, what is the average tonnage, show from low to high by the Type.
SELECT Type, AVG(Tonnage) FROM ship GROUP BY Type ORDER BY Type
SELECT "Type", AVG("Tonnage") FROM "ship" GROUP BY "Type" ORDER BY "Type" NULLS FIRST