PHP Registration script using prepared statements

Question

I have got the following registration code, it SEEMS to be working but it isn't actually inserting the entered information into my table. It all runs with no errors showing up, and the "echo 'end';" is displaying.

Edit, updated code: Now get this error

Warning: mysqli_stmt::bind_param(): Number of elements in type definition string doesn't match number of bind variables in C:\\xampp\\htdocs\\ppa\\test.php on line 19

Which is this line:

$insert_stmt->bind_param($email, $password, $random_salt, $user);

PHP:

   <?php
include "includes/db_connect.php";

if (isset($_POST['email'], $_POST['p'])) {
    $email = $_POST['email'];
    //Default user perms
    $perms = "user";

    $password = hash('sha512', $_POST['p']); //Need to add JavaScript to hash password before it gets here
    //Create random salt
    $random_salt = hash('sha512', uniqid(mt_rand(1, getrandmax()), true));

    //Create salted password
    $password = hash('sha512', $password.$random_salt);

    //Add insert to database script
    //Use prepared statements!
    if ($insert_stmt = $mysqli->prepare("INSERT INTO users (email, password, salt, perms) VALUES (?, ?, ?, ?)")) {
        $insert_stmt->bind_param($email, $password, $random_salt, $perms);
        $insert_stmt->execute();
    }
    echo "Email: ".$email."<br />";
    echo "Password: ".$password."<br />";
    echo "Random Salt: ".$random_salt."<br />";
    echo "Permissions: ".$perms."<br />";
}
?>

This is my db_connect.php page

<?php
define("HOST", 'localhost');
define("USER", 'ppa_user');
define("PASSWORD", 'password');
define("DATABASE", 'ppa');

$mysqli = new mysqli(HOST, USER, PASSWORD, DATABASE);

if ($mysqli->connect_errno) {
    //No database found, redirect to setup
    $url = "http://".$_SERVER['HTTP_HOST'].'/ppa/setup.php';
    header('Location: '.$url);
}
?>

Answer 1

Replace the following:

//Add insert to database script
    //Use prepared statements!
    if ($insert_stmt = $mysqli->prepare("INSERT INTO users (email, password, salt, perms) VALUES (?, ?, ?, ?)"));
    $insert_stmt->bind_param('ssss', $_POST['email'], $password, $random_salt, $user);

//Execute the prepared query
$insert_stmt->execute();
echo "end";

with:

//Add insert to database script
//Use prepared statements!
if ($insert_stmt = $mysqli->prepare("INSERT INTO users (email, password, salt, perms) VALUES (?, ?, ?, ?)")) {
    $insert_stmt->bind_param($_POST['email'], $password, $random_salt, $user);
    $insert_stmt->execute();
    echo "end";
}

Answer 2

check this

if ($insert_stmt = $mysqli->prepare("INSERT INTO users (email, password, salt, perms) VALUES (?, ?, ?, ?)"));
$insert_stmt->execute(array($_POST['email'], $password, $random_salt, $user));

Answer 3

为了解决这个问题，OP需使用以下代码得出结论：

$insert_stmt->bind_param("ssss", $email, $password, $random_salt, $perms);