CREATE TABLE flight (flno DECIMAL, origin VARCHAR, destination VARCHAR, distance DECIMAL, departure_date DATE, arrival_date DATE, price DECIMAL, aid DECIMAL)
CREATE TABLE certificate (eid DECIMAL, aid DECIMAL)
CREATE TABLE aircraft (aid DECIMAL, name VARCHAR, distance DECIMAL)
CREATE TABLE employee (eid DECIMAL, name VARCHAR, salary DECIMAL)

Bar chart of the total number from each origin, list by the x-axis in desc.
SELECT origin, COUNT(*) FROM flight GROUP BY origin ORDER BY origin DESC
SELECT "origin", COUNT(*) FROM "flight" GROUP BY "origin" ORDER BY "origin" DESC NULLS LAST