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

A bar chart showing the number of flights with price higher than 300 for each destination city, and list in descending by the Y.
SELECT destination, COUNT(destination) FROM flight WHERE price > 300 GROUP BY destination ORDER BY COUNT(destination) DESC
SELECT "destination", COUNT("destination") FROM "flight" WHERE "price" > 300 GROUP BY "destination" ORDER BY COUNT("destination") DESC NULLS LAST