songdogtech on "Accessing Remote MySQL databases"

Take a look at https://codex.wordpress.org/Class_Reference/wpdb for examples and methods.

And see https://codex.wordpress.org/WP_DEBUG

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );

in wp-config.php and the debug.log file will be in wp-content.

Add this

define( 'WP_DEBUG_DISPLAY', true);

to wp-config.php to log and dump them to the browser.