参数数量无效：绑定变量的数量与令牌的数量不匹配 - php 错误

运行以下代码时，我基本上收到以下错误：

无法运行查询：SQLSTATE[HY093]：参数数量无效：绑定变量的数量与令牌数量不匹配

我是 php 新手，不确定为什么会收到此错误...我过去曾将这段代码用于 INSERT （而不是 UPDATE）语句，并且运行良好。

该代码是从另一个站点复制的，只是用作测试......

// First we execute our common code to connection to the database and start the session 
require("common.php"); 

 $id = $_GET[id];

// This if statement checks to determine whether the registration form has been submitted 
// If it has, then the registration code is run, otherwise the form is displayed 
if(!empty($_POST)) 
{

    // Ensure that the user has entered a non-empty password 
    if(empty($_POST['password'])) 
    { 
        die("Please enter a password."); 
    } 

    // Ensure that the user has entered a non-empty username 
    if(empty($_POST['confirmpassword'])) 
    { 
        // Note that die() is generally a terrible way of handling user errors 
        // like this.  It is much better to display the error with the form 
        // and allow the user to correct their mistake.  However, that is an 
        // exercise for you to implement yourself. 
        die("Please confirm your password."); 
    } 

     if ($_POST["password"] == $_POST["confirmpassword"]) {

    // An INSERT query is used to add new rows to a database table. 
    // Again, we are using special tokens (technically called parameters) to 
    // protect against SQL injection attacks. 
    $query = "UPDATE Staff SET password=:password, salt=:salt WHERE id=:id"; 

    // A salt is randomly generated here to protect again brute force attacks 
    // and rainbow table attacks.  The following statement generates a hex 
    // representation of an 8 byte salt.  Representing this in hex provides 
    // no additional security, but makes it easier for humans to read. 
    $salt = dechex(mt_rand(0, 2147483647)) . dechex(mt_rand(0, 2147483647)); 

    // This hashes the password with the salt so that it can be stored securely 
    // in your database.  The output of this next statement is a 64 byte hex 
    // string representing the 32 byte sha256 hash of the password.  The original 
    // password cannot be recovered from the hash. 
    $password = hash('sha256', $_POST['password'] . $salt); 

    // Next we hash the hash value 65536 more times.  The purpose of this is to 
    // protect against brute force attacks.  Now an attacker must compute the hash 65537 
    // times for each guess they make against a password, whereas if the password 
    // were hashed only once the attacker would have been able to make 65537 different  
    // guesses in the same amount of time instead of only one. 
    for($round = 0; $round < 65536; $round++) 
    { 
        $password = hash('sha256', $password . $salt); 
    }  

    try 
    { 
        // Execute the query to create the user 
        $stmt = $db->prepare($query); 
        $stmt->execute(array(
        ':password' => $password,
        ':salt' => $salt)); 


    } 
    catch(PDOException $ex) 
    { 
        // Note: On a production website, you should not output $ex->getMessage(). 
        // It may provide an attacker with helpful information about your code.  
        die("Failed to run query: " . $ex->getMessage()); 
    } 

    // This redirects the user back to the login page after they register 
    header("Location: login.php"); 

    // Calling die or exit after performing a redirect using the header function 
    // is critical.  The rest of your PHP script will continue to execute and 
    // will be sent to the user if you do not die or exit. 
    die("Redirecting to login.php"); 
} 
}

多谢， 乔

你错过了:id范围：

$stmt->execute(array(
    ':password' => $password,
    ':salt' => $salt,
    ':id' => $id
));