我认为您无法确定 next id，因为有人可能会在您询问后插入新行为下一个ID.您至少需要一笔交易，并且如果我没记错的话，您只能在插入之后获得使用的实际ID，至少这是处理该ID的常用方法-请参见 http://dev.mysql.com/doc/refman/5.0/zh/getting-unique-id.html

I don't think you can ever be sure on the next id, because someone might insert a new row just after you asked for the next id. You would at least need a transaction, and if I'm not mistaken you can only get the actual id used after inserting it, at least that is the common way of handling it -- see http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html