保存产品时，将管理员用户名发送给MySql

I want to keep inventory logs. So I created in MySql a table cataloginventory_stock_item_log, which is updated by triggers to capture the qty BEFORE UPDATE and AFTER UPDATE from table cataloginventory_stock_item. So later I can run a report with the qty additions or subtractions.

My question is, I also want to capture the admin username (or email) so I know what user made the change to the quantity.

Is there a way the php files would pass to MySql the admin username out of the box? If not, what php files will have to be modified to accomplish this?

Below is the AFTER trigger I have used, I need to populate field by_user with the then current logged in @adminUser

CREATE TRIGGER qty_log_after_update
AFTER UPDATE
   ON cataloginventory_stock_item FOR EACH ROW

BEGIN
   INSERT INTO cataloginventory_stock_item_log
   set
   type = 'after',
   product_id = old.product_id,
     qty_before = new.qty,
     qty_changed = (new.qty-old.qty),
     created_at = now(),
     by_user = @adminUser;

END;

Joell