MySQL中是否可以仅更新第n次出现？

SET @row_number = 0;
UPDATE your_table
SET your_column = 'new_value'
WHERE (
    SELECT @row_number := @row_number + 1
) = n;

SET @row_number = 0;
UPDATE users
SET username = 'new_username'
WHERE (
    SELECT @row_number := @row_number + 1
) = 2;

UPDATE users
SET username = 'new_username'
LIMIT 1 OFFSET 1;