Get Return Value from SQL Stored Procedure using PHP

Question

So I have a php script that uses a stored procedure to interact with my SQL database. The stored procedure works just fine, the problem is I don't know how to get my php to echo the Return Value from the stored procedure. The stored procedure is basically activating an account using an activation key and sets the username and password.

It basically says "if the activation key provided does not have a username yet, set it to the one provided and RETURN 1, if it already has a username RETURN 2, and if the activation key does not exist RETURN 3". It works perfectly in SQL and even give the correct Return Value. Now how can I get my php to echo that? I have tried the following:

$link = sqlsrv_connect($myServer, array('Database' => $myDB, 'UID' => $myUser, 'PWD' => $myPass));
if($link === FALSE) {
    die('Could not connect: ' . sqlsrv_errors(SQLSRV_ERR_ALL));
}

$key = $_REQUEST['key'];
$username = $_REQUEST['username'];
$password = $_REQUEST['password'];

$query = "EXEC Activate_Account";
$query .=" @key = ";
$query .= $key;
$query .=", @user = ";
$query .= $username;
$query .=", @pass = ";
$query .= $password;

$result = sqlsrv_query($link, $query);

while($row = sqlsrv_fetch_array($result))
{
    echo $row[0];
}

sqlsrv_close($link);

and

while($row = sqlsrv_fetch_array($result))
{
    echo $row['Return Value'];
}

Neither of them echo anything.

Answer 1

To return a value with a stored procedure:

For example:

SQL :

CREATE DEFINER=`user`@`localhost` PROCEDURE `ProcedureName`(IN `Input_Value` INT, OUT `Out_val` INT)
    LANGUAGE SQL
    NOT DETERMINISTIC
    CONTAINS SQL
    SQL SECURITY DEFINER
    COMMENT ''
BEGIN
// Your SQL Code

    SET Out_val= Your Value;
    SELECT Out_val;
END

PHP Code:

$insert = "CALL ProcedureName(:Input_Value,
                             @Out_val)";
$bdd = new PDO('mysql:host=localhost;dbname=db-name', 'user', 'password');

$stmt = $bdd->prepare($insert);     
$stmt->bindParam(':Input_Value', $an_input_value, PDO::PARAM_STR); 

$stmt->execute();
$tabResultat = $stmt->fetch();
$Out_val = $tabResultat['Out_val'];
var_dump($Out_val);