我认为您永远无法确定 next id，因为有人可能会在您询问之后插入新行对于下一个 ID.你至少需要一个事务，如果我没记错的话，你只能在插入它之后获得实际使用的 id，至少这是处理它的常用方法——见 http://dev.mysql.com/doc/refman/5.0/en/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