PHP SQLite类

<?
/**
* sqlite类
* 2009-5-6
* 连万春
*
*/
class sqlite {
    // 当前sql指令
    public $_mquerystr = '';
    // 当前结果
    public $_mresult = null;
    // sqlite连接句柄
    protected $_msqlite;
    // 警告信息
    protected $_merrorinfo;
    /**
     * 数据库连接 构造类
     *
     * @param string $databasefile 数据库文件
     * @return unknown
     */
    public function __construct($databasefile){
        if(file_exists($databasefile)){
            $this->_msqlite = new pdo('sqlite:'.$databasefile);
        }else{
            $this->_merrorinfo="未找到数据库文件";
            return false;
        }
    }
    /**
     * 数据库有返回结果的语句操作
     *
     * @param srting $sql sql语句
     * @return unknown
     */
    public function getall($sql){
        if (empty($sql)) {
            $this->_merrorinfo="sql语句错误";
            return false;
        }
        $result=$this->_msqlite->prepare($sql);
        if ( false === $result) {
            return array();
        }
        $result->execute();
        $this->_mresult = $result->fetchall();
        if ( false === $this->_mresult) {
            return array();
        }
        return $this->_mresult;
    }
    /**
     * 执行insert,delete,updata操作
     *
     * @param srting $sql sql语句
     * @return unknown
     */
    public function query($sql){
        if (empty($sql)) {
            $this->_merrorinfo="sql语句错误";
            return false;
        }
        //$this->_msqlite->exec($sql)or die(print_r($this->_msqlite->errorinfo()));
        $this->_msqlite->exec($sql);
        return true;
    }
    /**
     * 返回错误信息
     *
     * @return unknown
     */
    public function seterror(){
        return $this->_merrorinfo;
    }
}
?>