[WordPress] Load All WordPress Custom Fields via Database Query

00-load-all-wordpress-custom-fields.php

<?php

function get_the_custom_fields() {

	global $wpdb;
  
	$results = $wpdb->get_results(
		$wpdb->prepare(
			"
			SELECT meta_key, meta_value
			FROM   $wpdb->postmeta
			WHERE  meta_key REGEXP '%s'
			", '^[_]'
		)
	);

	return $results;
}