如何使用Zend_Db获取Sqlite数据库的最后一个插入ID

I'm trying to fetch the last inserted row Id of a Sqlite DB in my PHP application. I'm using Zend Framework's PDO Sqlite adapter for database handling. the lastInsertId() method is supposed to give me the results, but it wouldn't. In PDO documentation in php.net I read that the lastInsertId() might not work the same on all databases. but wouldn't it work on sqlite at all? I tried overwriting the lastInsertId() method of the adapter by this:I'm trying to fetch the last inserted row Id of