插入多行时，如何使用“ ON DUPLICATE KEY UPDATE”增加MySql中的字段？

对于一行：

INSERT INTO table 
  (a, counter_elem) 
VALUES 
  (1, 1)
ON DUPLICATE KEY UPDATE counter_elem = counter_elem+1;

对于多行：

INSERT INTO table 
  (a, counter_elem) 
VALUES 
  (1, 1),
  (2, 1)
ON DUPLICATE KEY UPDATE counter_elem = ?;

这不起作用：

counter_elem = VALUES(counter_elem)+1