Сергей Волков

class SpammerIBlockElementUpdateHandler
{
    public static function runStatic(&$fields)
    {
        $self = new self();
        return $self->run($fields);
    }

    public  function run(&$arFields)
    { 
         //some code
    }
}

/*****************************/
$eventManager = \Bitrix\Main\EventManager::getInstance();
$eventManager->registerEventHandlerCompatible(
    "iblock",
    "OnAfterIBlockElementUpdate",
     $this->MODULE_ID,
     '\foo_spammer\events\SpammerIBlockElementUpdateHandler',
     "runStatic"
);

SELECT user_id, SUM(CASE WHEN value<0 THEN value ELSE 0 END) as spent, 
SUM(CASE WHEN value>0 THEN value ELSE 0 END) as received, SUM(value) as total
FROM table
GROUP BY user_id