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)

Show me a bar chart comparing the total number of captains of different classes.
SELECT Class, COUNT(Class) FROM captain GROUP BY Class
SELECT "Class", COUNT("Class") FROM "captain" GROUP BY "Class"