Mysqli query only works on localhost, not webserver

I have changed some of my old queries to the Mysqli framework to improve performance. Everything works fine on localhost but when i upload it to the webserver it outputs nothing. After connecting I check for errors and there are none. I also checked the php modules installed and mysqli is enabled.

I am certain that it creates a connection to the database as no errors are displayed. (when i changed the database name string it gave the error)

There is no output from the query on the webserver, which looks like this:

$mysqli = new mysqli("server", "user", "password");

if (mysqli_connect_errno()) {
   printf("Can't connect Errorcode: %s\n", mysqli_connect_error());
   exit;
}

// Query used  
$query = "SELECT name FROM users WHERE id = ?";

if ($stmt = $mysqli->prepare("$query")) 
{

    // Specify parameters to replace '?'
    $stmt->bind_param("d", $id);  

    $stmt->execute();

    // bind variables to prepared statement 
    $stmt->bind_result($_userName);

    while ($stmt->fetch()) 
    {
          echo $_userName;
    }


    $stmt->close();
 }
}

//close connection 
$mysqli->close(); 

As I said this code works perfectly on my localserver just not online. Checked the error logs and there is nothing so everything points to a good connection. All the tables exists as well etc. Anyone any ideas because this one has me stuck! Also, if i get this working, will all my other queries still work? Or will i need to make them use the mysqli framework as well? Thanks in advance.

EDIT:

Ok Ive done some 'debugging' to see what is happening. There is data in the table i'm querying that matches the query. I did the following to check the prepare statement:

echo "debug 1";

if ($stmt = $mysqli->prepare("$shiftQuery"))  
{

echo "debug 2";
printf("Error: %s.\n", $stmt->error);

etc...
}

So basically it should output 'debug 1' before the statment is prepared (Which it does). Then after it should output 'debug 2' and any errors that occured.

The problem i开发者_如何学Cs here somewhere as it doesnt reach the debug 2 line in the IF statement. Since the connection details are fine, i cant really see why the $mysqli object wouldnt be created. That give anyone any further ideas???

thanks

Each call to a mysqli/stmt method can fail. You should check each and every one.
Try it with error_reporting(E_ALL) and maybe display_error=On

<?php
error_reporting(E_ALL); ini_set('display_errors', 1);

// passing database name as fourth parameter
$mysqli = new mysqli("server", "user", "password", 'dbname');
if (mysqli_connect_errno()) {
   printf("Can't connect Errorcode: %s\n", mysqli_connect_error());
   exit;
}

// Query used  
$query = "SELECT name FROM users WHERE id = ?";

if ( false===($stmt=$mysqli->prepare("$query")) ) {
  echo 'mysqli::prepare failed: ', htmlspecialchars($mysqli->error);
  die;
}

// Specify parameters to replace '?'
$rc = $stmt->bind_param("d", $id);  
if ( !$rc ) {
  echo 'bind_param failed: ', htmlspecialchars($stmt->error);
  die;
}

echo '<pre>Debug: execute()</pre>';
$rc = $stmt->execute();
if ( !$rc ) {
  echo 'execute failed: ', htmlspecialchars($stmt->error);
  die;
}

echo '<pre>Debug: bind_result()</pre>';
// bind variables to prepared statement 
$rc = $stmt->bind_result($_userName);
if ( !$rc ) {
  echo 'bind_result failed: ', htmlspecialchars($stmt->error);
  die;
}

echo '<pre>Debug: fetch()</pre>';
while ($stmt->fetch()) 
{
  echo 'username: ', $_userName;
}
echo '<pre>Debug: stmt close()</pre>';
$stmt->close();

echo '<pre>Debug: mysqli close()</pre>';
$mysqli->close();

MySQL user permission is host sensitive -- it may give user1 from localhost and user1 from other host different permission.

GRANT ALL ON *.* TO user@'%' IDENTIFIED BY 'password';

Mysqli framework does not improve performance.
Error checking must be done not only after connect but after each query execute.

Check $stmt->error for errors
Or try to check against throwed exception

Is Id an integer? I normally run my mysqli like

$sql = "SELECT name FROM users WHERE id = ?";
            if($stmt = $mysqli->mysqli->prepare($sql)){
              $stmt->bind_param("i", $id);
                    if($stmt->execute()){
                        $stmt->bind_result($name);
                        $stmt->store_result();
                        if($stmt->fetch()){
                            return $name;
                         }else{
                             return 'Not Found';
                         }      
                    }else{
                        return 'Execute Error';
                    }

            }else{
                return 'SQL Error';
            }

Hope that helps