17.Monasteries by Continents and Countries

UPDATE
    countries
SET
    country_name = 'Burma'
WHERE
    country_name = 'Myanmar';

INSERT INTO
    monasteries (monastery_name, country_code)
VALUES
    ('Hanga Abbey', (SELECT country_code FROM countries WHERE country_name = 'Tanzania')),
    ('Myin-Tin-Daik', (SELECT country_code FROM countries WHERE country_name = 'Myanmar'));

SELECT
    con.continent_name,
    c.country_name,
    count(m.id) AS monasteries_count
FROM
    continents AS con
LEFT JOIN
    countries AS c
ON
    c.continent_code = con.continent_code
LEFT JOIN
    monasteries AS m
ON m.country_code = c.country_code
WHERE
    NOT c.three_rivers
GROUP BY
    c.country_name,
    continent_name
ORDER BY
    monasteries_count DESC, country_name;