Get product with stock < 0

SELECT f_get_warehouse_code(A.warehouse_id) AS warehouse_code,
    f_get_warehouse_name(A.warehouse_id) AS warehouse_name,
    f_get_product_code(A.product_id) AS product_code,
    f_get_product_name(A.product_id) AS product_name,
    A.product_status, SUM(A.qty) AS qty
FROM in_product_balance_stock A
GROUP BY A.warehouse_id, A.product_id, A.product_status
HAVING SUM(A.qty) < 0