Create a View from custom database
You can connect a external database inorderto let Drupal Know about it:

$databases['external']['default'] = array(
  'database' =&gt; 'custom_database',
  'username' =&gt; 'root',
  'password' =&gt; '',
  'prefix' =&gt; '',
  'host' =&gt; php_sapi_name() == 'cli' ? '127.0.0.1' : 'localhost',
  'port' =&gt; '3306',
  'namespace' =&gt; 'Drupal\\Core\\Database\\Driver\\mysql',
  'driver' =&gt; 'mysql',
);


Then you can connect to that database:

/*
* Switch to external db
*/
\Drupal\Core\Database\Database::setActiveConnection('custom_database');

/*
* Get connection
*/
$db = \Drupal\Core\Database\Database::getConnection();


Then do you stuff and don't footgrt to switch again to the standard database:

/*
* Switch back
*/
\Drupal\Core\Database\Database::setActiveConnection();


You can store your external database info into a content type programatically and the show in views.