MysqlHooks.php

<?php

namespace Drupal\mysql\Hook;

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Hook\Attribute\Hook;

/**
 * Hook implementations for mysql.
 */
class MysqlHooks {
    
    /**
     * Implements hook_help().
     */
    public function help($route_name, RouteMatchInterface $route_match) {
        switch ($route_name) {
            case 'help.page.mysql':
                $output = '';
                $output .= '<h2>' . t('About') . '</h2>';
                $output .= '<p>' . t('The MySQL module provides the connection between Drupal and a MySQL, MariaDB or equivalent database. For more information, see the <a href=":mysql">online documentation for the MySQL module</a>.', [
                    ':mysql' => 'https://www.drupal.org/docs/core-modules-and-themes/core-modules/mysql-module',
                ]) . '</p>';
                return $output;
        }
    }

}