Summary Cst8116

-- bonsi nkamseh
-- 041060183
-- question 1
use flightdb;
SELECT COUNT(*) FROM airlines;
-- question 2
SELECT AVG(elevation) FROM airports;
-- question 3
SELECT MAX(elevation), MIN(elevation) FROM airports;
-- question 4
SELECT country_id, AVG(elevation) FROM airports GROUP BY country_id;
-- question 5
SELECT country_id, AVG(elevation) FROM airports GROUP BY country_id ORDER BY
country_id;
-- question 6
SELECT country_id, AVG(elevation) FROM airports GROUP BY country_id ORDER BY
AVG(elevation) desc;
-- question 7
SELECT country_id, AVG(elevation) FROM airports GROUP BY country_id HAVING
AVG(elevation) >= 300 ORDER BY AVG(elevation) desc;


-- question 8
SELECT COUNT(*) FROM aircrafts WHERE name = 'Boeing' AND description LIKE '74%';
-- question 9
SELECT COUNT(DISTINCT wake_size) FROM aircrafts WHERE name IN ('Boeing', 'Airbus');

-- question 10
select count(*) from airlines where active = 'Y' and country_id = '208';