Purpose of this Code-Snippet for WordPress 'wp-config.php' is to have a Single Configuration that does not need to be changed each Time you push a new Release to Dev / Staging / Live-Servers

wp-config.php

<?php 
if (file_exists(dirname(__FILE__) . '/wp-config-local.php')) {

  // If File exists include Config for Dev-Server Environment
  include(dirname(__FILE__) . '/wp-config-local.php');
  
} elseif (file_exists(dirname(__FILE__) . '/wp-config-staging.php')) {

  // If File exists include Config for Staging-Server Environment
  include(dirname(__FILE__) . '/wp-config-staging.php');
  
} else {

 // Config for Live-Server Environment
 define('DB_NAME', 'dbname');
 define('DB_USER', 'dbuser');
 define('DB_PASSWORD', 'password');
 define('DB_HOST', 'localhost');
 define('DB_CHARSET', 'utf8');
 define('DB_COLLATE', '');
 define('DISALLOW_FILE_EDIT', true );
 define('WP_DEBUG', false);
 
}

// Other stuff from the usual wp-config.php like SALTS etc.

?>