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

Stacked bar of class and the number of class colored by Rank, and display in asc by the x axis please.
SELECT Class, COUNT(Class) FROM captain GROUP BY Rank, Class ORDER BY Class
SELECT "Class", COUNT("Class") FROM "captain" GROUP BY "Rank", "Class" ORDER BY "Class"