Why it doesn't save data on the online database?

I'm trying to register users in my program and save the data in an online database. I have followed this tutorial:

but it's outdated, so I have tried to make it work but I don't know what is the error.

I have the script Registro.cs:

Code (CSharp):

1. public class Registro : MonoBehaviour
2. {
3.     public static string usuario = "", email = "";
4.     private string contraseña = "", reContraseña = "", mensaje = "";
5.  
6.     public Text txtUsuario, txtEmail, txtContraseña, txtReContraseña;
7.     public InputField inputUsuario, inputEmail, inputContraseña, inputReContraseña;
8.     public Button botonRegistrar;
9.  
10.     void Start()
11.     {
12.         botonRegistrar.onClick.AddListener(ButtonRegistrarClicked);
13.     }
14.  
15.     void Update()
16.     {
17.         usuario = inputUsuario.text;
18.         email = inputEmail.text;
19.         contraseña = inputContraseña.text;
20.         reContraseña = inputReContraseña.text;
21.     }
22.  
23.     void ButtonRegistrarClicked()
24.     {
25.         mensaje = "";
26.  
27.         if(usuario == "" || email == "" || contraseña == "")
28.         {
29.             mensaje = "Por favor, rellena todos los campos";
30.             print(mensaje);
31.         }
32.         else
33.         {
34.             if(contraseña == reContraseña)
35.             {
36.                 WWWForm form = new WWWForm();
37.                 form.AddField("usuario", usuario);
38.                 form.AddField("email", email);
39.                 form.AddField("contraseña", contraseña);
40.  
41.                 UnityWebRequest www = UnityWebRequest.Post("http://linxdatos.000webhostapp.com/Registrar.php", form);
42.                 StartCoroutine(registrar(www));
43.             }
44.             else
45.             {
46.                 mensaje += "Tu contraseña no coincide";
47.                 print(mensaje);
48.             }
49.         }
50.     }
51.  
52.     IEnumerator registrar(UnityWebRequest www)
53.     {
54.         yield return www.SendWebRequest();
55.         if (www.isNetworkError || www.isHttpError)
56.             {
57.                 Debug.Log(www.error);
58.             }
59.             else
60.             {
61.                 print(www.downloadHandler.text);
62.                 Debug.Log("Form upload complete!");
63.             }
64.     }
65. }

Sorry for writing all the script here, but I don't know where is the error. When I click the button botonRegistrar, it sends the data that you can see there to a free hosting database. I have written Debug.Log(www.error); to check if there is an error connecting to the database, but it says that it's correct. I have tried to print(form.data); to check it and it prints System.Byte[], so maybe that's the error?

Here is the php script:

<?php
$usuario = $_POST['usuario'] ?? '';
$email = $_POST['email'] ?? '';
$contraseña = $_POST['contraseña'] ?? '';
$nombreservidor = "localhost";
$usuariodb = "id11649923_usuario";
$contraseñadb = "linx1234";
$nombredb = "id11649923_linxdb";
$conexion = new mysqli($nombreservidor, $usuariodb, $contraseñadb, $nombredb);
if(!$conexion)
{
die("Conexión fallida.". mysqli_connect_error());
}
$sql = "SELECT * FROM usuarios WHERE `usuario`='".$usuario."'";
$resultado = mysqli_query($conexion, $sql);
if(mysqli_num_rows($resultado) == 0)
{
$query = "INSERT INTO `usuarios` ( `id` , `usuario` , `email` , `contraseña` ) VALUES ('' , '".$usuario."' , '".$email."' , '".$contraseña."') ; ";
if ($query)
{
die("Usuario creado con éxito");
}
else
{
die("Error: " . mysql_error());
}
}
else
{
die("El usuario ya existe");
}
?>

Here it does the connection and insert the values in the database, but it's inserting nothing.

 

I suggest you always use same Unity version as per tutorial.

 

Yeah I know, that's why I have used UnityWebRequest instead of WWW.

 

Check what you sending. Check what you are receiving.
On PHP side, print out what you are getting.

 

As I have said, when I print form.data it returns System.Byte[]. What do I print on PHP?

 

Variables requested by $_POST.
Check your http://linxdatos.000webhostapp.com/Registrar.php if works correctly, without Unity.
Investigate following.

Code (CSharp):

1. bool(false) string(107) "INSERT INTO `usuarios` ( `id` , `usuario` , `email` , `contraseña` ) VALUES ('' , '' , '' , '') ; " Error: Incorrect integer value: '' for column `id11649923_linxdb`.`usuarios`.`id` at row 1

Also, make sure, you change DB, login and password now, since you exposed them to public.

 

Like Antypodish said.
Also here

Code (CSharp):

1. $query = "INSERT INTO `usuarios` ( `id` , `usuario` , `email` , `contraseña` ) VALUES ('' , '".$usuario."' , '".$email."' , '".$contraseña."') ; ";

id is INTEGER 100%. And when you're trying to insert into db you'll trying to add a string.
use this

Code (CSharp):

1. $query = "INSERT INTO `usuarios` ( `id` , `usuario` , `email` , `contraseña` ) VALUES (null , '".$usuario."' , '".$email."' , '".$contraseña."') ; ";