Why won't my code populate a row in the mysql table?
<p>I am trying to allow for user registration, and the code comes back without any errors, but nothing shows up in my db. I can't for the life of me find out why. I don't see anything wrong, but maybe one of you can help me?</p>

<p>Here's the full php file:</p>

<pre><code>&lt;?php

require "includes/constants.php";

$conn = new mysqli(DB_SERVER, DB_USER, DB_PASSWORD, DB_NAME);

if(isset($_POST['username'])) {
    $username = $_POST['username'];
    $uLength = strlen($username);
}

if ($uLength &gt;= 4 &amp;&amp; $uLength &lt;= 15)
{
}
else
{
    die("Your username must be between 4 and 15 characters.");
}

if($username == "")
{
    die("You didn't tell me what to call you! Please enter a username.");
}

if(isset($_POST['pwd'])) {
    $pwd = $_POST['pwd'];
    $pLength = strlen($pwd);
}

if ($pLength &gt;= 6 &amp;&amp; $pLength &lt;= 41)
{
}
else
{
    die("Password must be between 6 and 41 characters.");
}

if($pwd == "")
{
    die("Please enter a password and verify it.");
}

if(isset($_POST['pwd_conf'])) {
    $pwd_conf = $_POST['pwd_conf'];
}
if($pwd != $pwd_conf)
{
    die("Ouch! Your passwords don't match! Try again.");
}

if(isset($_POST['email'])) {
    $email = $_POST['email'];
    $email1 = "@";
    $email_check = strpos($email,$email1);
}

$user_check = "SELECT username FROM users WHERE username='$username'";
if($stmt = mysqli_prepare($conn,$user_check)) {
    mysqli_stmt_execute($stmt);

    if(mysqli_stmt_num_rows($stmt) &gt; 0){
        die("Username is already in use!&lt;br&gt;");
    }
}

$query = "INSERT INTO users (username, password, email) VALUES ('$username', '$pwd', '$email')";

if(!$query)
{
    die("Unfortunately, we can't sign you up because we have problems: ".mysql_error());
}
else
{
    header("Location: login.php");
}

?&gt;    
</code></pre>
