db的随机结果

I have this php script in an external file trying to get random question from a db:

<?php
//connect to db
require_once('db.php');

$id=rand(0,13); //2nd number = highest ID

if ($resQ = $mysqli->query("SELECT Quest FROM qa WHERE ID='$id'")){

   echo "" . $resQ['Quest'] . ""; //This is Line 9

   $resQ->close();
}
$mysqli->close();
?>

and I call it in my page like this

<body>
code...

<?php require_once('script/m_q.php'); ?>

...code
</body>

But i get error:

Fatal error: Cannot use object of type mysqli_result as array in .../m_q.php on line 9

Any help? Thank you

Thank you all... Unfortunatelly I can accept just one answer, si I choose the one that answered first.

mysqli::query does return a result set, you have to fetch rows in order to access the columns.

You have to call the fetch_assoc() method of the mysqli_result object to access the data:

<?php
//connect to db
require_once('db.php');

$id=rand(0,13); //2nd number = highest ID

if ($resQ = $mysqli->query("SELECT Quest FROM qa WHERE ID='$id'")){

   $data = $resQ->fetch_assoc();
   echo "" . $data['Quest'] . ""; //This is Line 9

   $resQ->close();
}
$mysqli->close();

?>

You need to fetch the data first.

$rs = $resQ->fetch_assoc();
echo $rs['Quest'];

$resQ cannot get in an if statement... assign data to it 1st using mysql_fetch_assoc or mysql_fetch_array.