php - mysqli returns nothing

Question

I have a mysql table like this

name    adults  children
single  1        0  
double  2        0  
suite   3        0  

But I'm unable to retrieve the values of "adults" and "children" with this function

function getInfo($mysqli, $c, $query){

    // WARNING! THIS LINE IS NOT THE SQL QUERY BUT JUST AN ERROR LOG!
    error_log("query is: SELECT " . $query . " FROM categories WHERE `name` = " . $c);

    $mysqli->select_db("hotel");

    $sql = $mysqli->prepare("SELECT ? FROM categories WHERE `name` = ?
    LIMIT 0, 999999");

    $sql->bind_param('ss', $query, $c);



    $sql->bind_result($result);

    while ($sql->fetch())
        return($result);

}

error log shows the variables are correctly passed to the function:

[15-Apr-2013 19:36:10] SELECT adults FROM categories WHERE `name` = single

why is this function returning NULL?

Answer 1

You miss $sql->execute();

$sql->bind_param('ss', $query, $c);
$sql->execute();
$sql->bind_result($result);