MySQL 8.0

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CREATE TABLE goods (id INT, san INT, quantity INT)
INSERT INTO goods (id, san, quantity)
VALUES
(1,1,1),
(2,1,2),
(3,2,3),
(4,2,4),
(5,3,5),
(6,4,6),
(7,4,7);
CREATE TABLE order_elements (order_id INT, san INT, quantity INT);
INSERT INTO order_elements (order_id, san, quantity)
VALUES
(10,1,11),
(25,2,22),
(25,2,33),
(25,3,44),
(40,3,55),
(40,4,66);
SELECT * FROM goods;


id
san
quantity


1
1
1

2
1
2

3
2
3

4
2
4

5
3
5

6
4
6

7
4
7


UPDATE `goods` gs 
INNER JOIN ( SELECT * 
             FROM order_elements 
             WHERE order_id=25 ) oe ON gs.san=oe.san 
SET gs.quantity=gs.quantity+oe.quantity;
SELECT * FROM goods;


id
san
quantity


1
1
1

2
1
2

3
2
25

4
2
26

5
3
49

6
4
6

7
4
7