使用bind_param时是否可以使用fetch_object？ (PHP /库MySQLi)

我有个问你们.我正试图让我尽可能安全地运行 MySQL.我现在想知道在准备好语句,绑定参数并执行语句之后是否可以使用MySQLi获取对象.

例：

$sql = $mysqli->prepare('SELECT * FROM users WHERE username = ?;');
$sql->bind_param('s',$userName);

$username = 'RastaLulz';

$sql->execute();
$object = $sql->fetch_object();
echo $object->mail;

我收到以下错误：

Fatal error: Call to a member function fetch_object() on a non-object in C:\xampp\htdocs\PrOCMS\DevBestCMS\inc\global\class.mysql.php on line 23

但是,当我添加“$sql-> result_metadata();”我没有收到错误,但它没有返回结果(它只是NULL).

$sql = $mysqli->prepare('SELECT * FROM users WHERE username = ?;');
$sql->bind_param('s',$userName);

$username = 'RastaLulz';

$sql->execute();
$result = $sql->result_metadata();
$object = $result->fetch_object();
echo $object->mail;

这是你如何在不绑定参数的情况下完成的：

$sql = $mysqli->query("SELECT * FROM users WHERE username = 'RastaLulz';");
$object = $sql->fetch_object();
echo $object->mail;

这是我当前的MySQL类 – 只需要让execute函数正常工作.
http://uploadir.com/u/lp74z4

任何帮助是,将不胜感激！

// returns an array of objects
public function stmtFetchObject(){

    $rows=array(); //init

    // bind results to named array
    $meta = $this->stmt->result_metadata();
    $fields = $meta->fetch_fields();

    foreach($fields as $field) {
            $result[$field->name] = "";
            $resultArraY[$field->name] = &$result[$field->name];
    }

    call_user_func_array(array($this->stmt,'bind_result'),$resultArray);

    // create object of results and array of objects
    while($this->stmt->fetch()) {
            $resultObject = new stdClass();

            foreach ($resultArray as $key => $value) {
                $resultObject->$key = $value;
            }

            $rows[] = $resultObject;
    }

    return $rows;
}