Connect to a database and display results in a table?

I have a simple MYSQL table.

SELECT * FROM countries;

+----------------------------------------------------+
| id | country                                |
+----------------------------------------------------+
| 1| United Kingdom                       |
| 2| United States                         |
| 3| Afghanistan                            |
| 4| Albania                                  |
+----------------------------------------------------+

I’ve searched hight & low.

What is the best way to query a MYSQL table (countries) and display the results in a Drupal page?

Drupal version: 


Source: https://www.drupal.org/taxonomy/term/4/feed