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)

Give me a bar chart for mean tonnage of each type, and show from low to high by the bar.
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