Connecting a Drupal application to multiple Databases

Issue

How do I connect to a database outside of Drupal?

Resolution

There are steps listed out in this Drupal.org page:

https://www.drupal.org/docs/7/creating-custom-modules/howtos/how-to-connect-to-multiple-databases-within-drupal

In short:

1. Define the secondary Database in your "settings.php",
2. Switch to the Database inside of your module,
3. Query that database,
4. Swap back to the default Database when finished.