我试图使用mysql实现黑客新闻算法并得到以下错误
Double value is out of range in
pow(((unix_timestamp() - unix_timestamp(postDateTime))/3600 + 1),1.5)
Where the value of postDateTime is 2012-12-15 10:41:31
如果我将上述实现为
pow(((unix_timestamp() - unix_timestamp(cast(postDateTime as signed)))/3600 + 1),1.5)
它工作得很好,但我不明白它背后的原因