DB_project_hints

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Registr : MonoBehaviour
{
    public InputField groupfield;
    public InputField namefield;
    public InputField surnamefield;

    public Button submitButton;

    public void CallRegister()
    {
        StartCoroutine(Register());

    }

    IEnumerator Register()
    {
        WWWForm form = new WWWForm();
        form.AddField("name", namefield.text);
        form.AddField("surname", surnamefield.text);
        form.AddField("group", groupfield.text);
        WWW www = new WWW("http://localhost/sqlconnect/register.php", form);
        yield return www;
        if (www.text == "0"){
            Debug.Log("User created ");
        }
        else
        {
            Debug.Log("User creation failed:" + www.text);
        }
    }

    public void VerifyInputs()
    {
        submitButton.interactable = (namefield.text.Length >= 2 && surnamefield.text.Length >= 4);
    }

}

----------------------------------------------------
php:
<?php

    $con = mysqli_connect('localhost','root','root','unityaccess');

    if (mysqli_connect_errno())
    {
        echo "1";
        exit();
    }

    $username = $_POST["name"];
    $usersurname = $_POST["surname"];
    $usergroup = $_POST["group"];

    $insertuserquery = "INSERT INTO students (username,usersurname,usergroup) VALUES ('" . $username . "', '" . $usersurname ."', '" .$usergroup ."');";
    mysqli_query($con, $insertuserquery) or die ("4: insert failed");

    echo("0");

?>