PHP MySQL代码出错

Question

I seem to having trouble with some of my PHP. It takes data from an HTML page and then adds it to a MySQL database, but the information does not appear.

<?php

    // Variables
    $email = $_POST["email"]; 
    $username = $_POST["username"]; 
    $password = $_POST["password"]; 
    $passwordconfirmation = $_POST["passwordconfirmation"];

    // Failure
    if ($password !== $passwordconfirmation)
    { 
       echo "The password fields do not match. Please enter your password again."; 
    } 

    // Success
    else
    {
    $connection = mysqli_connect("*****.com", "*****", "*****", "charlesfriessdatabase"); // Connect

     // Error Message
    if (!$connection)
    {
        die ("Error"); 
    }

    mysqli_query("INSERT INTO accounts (email, username, password) VALUES ($email, $username, $password)"); // Inserter

    mysqli_close($connection); // Connection Closer

    echo "You have successfully signed up! Please check your email to confirm your account."; // Success Message
}

?>

Answer 1

In the variables you need to put the ' Try Add this char and let us know.

This is how supposed to be:

mysqli_query("INSERT INTO accounts (email, username, password) VALUES ('$email', '$username', '$password')");