mysql - 设置旧值 = 旧值 + 新值 ON DUPLICATE KEY

Question

我看到这个例子，我想用旧值+新值更新旧值

INSERT INTO mytable (id, a, b, c)
VALUES (1, 'a1', 'b1', 'c1'),
(2, 'a2', 'b2', 'c2'),
(3, 'a3', 'b3', 'c3'),
(4, 'a4', 'b4', 'c4'),
(5, 'a5', 'b5', 'c5'),
(6, 'a6', 'b6', 'c6')
ON DUPLICATE KEY UPDATE id=VALUES(id),
a=VALUES(old a+ new a),
b=VALUES(old b+ new b),
c=VALUES(old c+ new c);

Answer 1

谢谢，我已经解决了我的问题

INSERT INTO mytable (id, a, b, c)
VALUES (1, 'a1', 'b1', 'c1'),
(2, '5', '6', '7'),
(3, '5', '6', '7'),
(4, '5', '6', '7'),
(5, '5', '6', '7'),
(6, '5', '6', '7')
ON DUPLICATE KEY UPDATE id=VALUES(id),
a=a+VALUES(a),
b=b+VALUES(b),
c=c+VALUES(c);