how to take a value less than 0 if recorded obtained like this?

select c.location_id as id_gudang, c.location_name as nama_gudang, a.item_code as id_barang, a.item_name as nama_barang, sum(b.item_qty) as qty from t_inventory as a join t_inventory_transaction as b on a.item_id = b.item_id join t_site_location as c on b.whse_id = c.location_id group by a.item_code this data from query enter image description here