mysql - mySQL - 我只想选择 75 个最近的帖子，除非一列认为帖子是“永久的”

Question

这是我尝试过的：

SELECT *
FROM   posts
WHERE (
  post != ''
  AND timestamp >= (
    SELECT `posts`.`timestamp`
    FROM posts
    WHERE post != ''
    ORDER BY timestamp DESC
    LIMIT 1
    OFFSET 75 )
) OR (
  post != ''
  AND authorization = 'permanent'
)
ORDER BY `posts`.`id` ASC 

第一个 WHERE 选择最近的 75 个，但代码忽略了那些应该是永久的。我不知道为什么。提前致谢。