<?php
if (count($_POST) > 0) {
    //var_dump($_POST);

    $dbHost = "localhost";
    $dbUser = "root";
    $dbPass = "root";
    $dbName = "test23052017";
    $dbConnection = mysqli_connect($dbHost, $dbUser, $dbPass, $dbName);

    if(mysqli_connect_errno()){
        die("Database connection error ".mysqli_connect_error()." => ".mysqli_connect_errno());
    }

    $name = $_POST['name'];
    $lastname = $_POST['last_name'];
    $mail = $_POST['mail'];
    $password = $_POST['password'];
    $rpassword = $_POST['repeat_password'];
    $zip = $_POST['zip_code'];
    $birthday = $_POST['birthday'];

    $error = false;
    $errormsg = '';

    if (empty($name) || empty($mail) || empty($lastname) || empty($password) || empty($rpassword) || empty($zip)) {
        $error = true;
        $errormsg .= 'Fill all inputs<br>';
    }

    if ($password != $rpassword) {
        $error = true;
        $errormsg .= 'Passwords not maching<br>';
    }

    if (!$error) {
        $query = "INSERT INTO users
                (name, lastname, mail, password, zip_code, birthday)
                VALUES
                ('$name', '$lastname', '$mail', '$password', '$zip', '$birthday')";
        $result = mysqli_query($dbConnection, $query);

        if($result){
            echo "Success";
        }else{
            die("Query failed ".mysqli_error($dbConnection));
        }
    } else {
        echo 'Errors: ' . $errormsg;
    }


    mysqli_close($dbConnection);

}

?>

<form method="post" action="">
    <input type="text" name="name" value="" placeholder="Name"/><br>
    <input type="text" name="last_name" value="" placeholder="Last name" /><br>
    <input type="text" name="mail" value="" placeholder="Email" /><br>
    <input type="password" name="password" value="" placeholder="Password" /><br>
    <input type="password" name="repeat_password" value="" placeholder="Repeat password" /><br>
    <input type="text" name="zip_code" value="" placeholder="Zip code" /><br>
    <input type="text" name="birthday" value="" placeholder="Birthday" /><br><br>
    <input type="submit" value="Register" />
</form>
<?php


?>