语法错误MySQL IF EXISTS

Question

我有投票的SQL查询，检查投票是否存在，但它一直给我语法错误

IF EXISTS (SELECT * FROM `votes` WHERE `id` = 298 AND `author` = 'noo

子查询本身运行良好。

IF EXISTS (SELECT * FROM `votes` WHERE `id` = 298 AND `author` = 'noob') THEN
    'exist'
ELSE
    INSERT INTO `votes`(`id`, `author`, `type`, `value`) VALUES (298, "noob", "upvote", 1)
    'upvoted'
END IF