MySQL 5.6

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select version();


version()


5.6.51


CREATE TABLE `stock_table` (
  `ID` int(11) NOT NULL,
  `product_code` varchar(20) NOT NULL,
  `qty` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO `stock_table` (`ID`, `product_code`, `qty`) VALUES
(1, 'PO1', 5),
(2, 'PO1', 12),
(3, 'PO1', 10),
(4, 'PO1', 8),
(5, 'PO1', 9),
(6, 'PO1', 16);

Records: 6  Duplicates: 0  Warnings: 0


select t.*,
       (select sum(`qty`) from `stock_table` where `ID` <= t.`ID` ) as "Qty Total"
  from `stock_table` t
 order by t.`ID`;
 


ID
product_code
qty
Qty Total


1
PO1
5
5

2
PO1
12
17

3
PO1
10
27

4
PO1
8
35

5
PO1
9
44

6
PO1
16
60