Exercise : Dense Populations

Which countries have the densest population (population divided by surface area)? Show the densest ones at the top.

+--------------+------------+--------------+--------------------+
| name         | population | surface_area | population_density |
+--------------+------------+--------------+--------------------+
| Macao        |     473000 |        18.00 |       26277.777778 |
| Monaco       |      34000 |         1.50 |       22666.666667 |
| Hong Kong    |    6782000 |      1075.00 |        6308.837209 |
| Singapore    |    3567000 |       618.00 |        5771.844660 |
| Gibraltar    |      25000 |         6.00 |        4166.666667 |
...
+--------------+------------+--------------+--------------------+
239 rows in set (0.00 sec)

Exercise Solution

SELECT name, population, surface_area,
       population / surface_area as population_density
FROM countries
ORDER BY population_density DESC;