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

Bar graph to show how many nationality from different nationality
SELECT Nationality, COUNT(Nationality) FROM ship GROUP BY Nationality
SELECT "Nationality", COUNT("Nationality") FROM "ship" GROUP BY "Nationality"