PDO

$dsn = "mysql:host=xxx;dbname=xxx;charset=utf8";
        $username = "xxx";
        $password = "xxx";
        $options = [
            \PDO::ATTR_DEFAULT_FETCH_MODE => \PDO::FETCH_ASSOC
        ];
        $pdo_object = new \PDO($dsn, $username, $password, $options);
        $sql = "xxx";
        $sttm = $pdo_object->prepare($sql);
        $sttm->bindValue(":xxx", "xxx");
	//执行SQL,返回1表明成功执行
	$sttm->execute();
	//执行SQL后,查询操做须要调用该方法获取结果
        $sttm->fetchAll();
	//获取错误信息
        $sttm->errorInfo();

ERROR

    could not find driver ,一开始觉得是pdo扩展没开启,最后发现是构造函数的参数$dsn写错了