Method getGroupRules

public static function getGroupRules()
{
    $db = Factory::getDBO();
    $query = 'SELECT a.id, a.type, a.minimum_sum' . ' FROM #__phocacart_groups AS a' . ' ORDER BY a.id';
    $db->setQuery($query);
    $groups = $db->loadAssocList();
    return $groups;
}