Save data to mysql

This is my script in php:

 $con = mysqli_connect('localhost', 'root', 'root', 'unityaccess');   //la primera var es la posicion relativa de la ddbb, nombre y paswword en las sgtes

  //check that conection happenned
  if(mysqli_connect_errno())  //check or si pasaron algunos errores, si es true esq hubieron errores.
  {
       echo "1: conection failed"; // error code #1 = connection failed
       exit();
  }


  $username = $_POST["name"];
  $newscore = $_POST["score"];

  $namecheckquery = "SELECT username, score FROM players WHERE username = ' " . $username . " ' ";
 
 
  $namecheck = mysqli_query($con, $namecheckquery) or die("2: name check query failed"); // error code #2 = name check query failed
  if(mysqli_num_rows($namecheck) != 1)
  {
      echo "5: Either no user with name or more than one"; // error code #5 number of names maching !=1
      exit();
  }

  $updatequery = "UPDATE players SET score = ".$newscore." WHERE username = '".$username."' ";
  mysqli_query($con, $updatequery) or die ("7:  Save query failed");

  echo "0";

This my script in C#:

 public Text playerDisplay;
 public Text scoreDisplay;
 // Start is called before the first frame update
 void Awake()
 { 
 
     if(DBManager.username == null)
     {
         UnityEngine.SceneManagement.SceneManager.LoadScene(0);
     }
     playerDisplay.text = "Player : " + DBManager.username;
     scoreDisplay.text = "score: " + DBManager.score;
     
   

 public void CallSaveData()
 {
     StartCoroutine(SavePlayerData());
 }

 IEnumerator SavePlayerData()
 {
     WWWForm form = new WWWForm();
     form.AddField("name", DBManager.username); 
     form.AddField("score", DBManager.score); //
     WWW www = new WWW("http://localhost:8888/sqlconnect/savedata.php", form);
     yield return www;
     if(www.text == "0")
     {
         Debug.Log("Game Saved");



     }
     else
     {
         Debug.Log("Save failed. Erro # " + www.text);
     }

     DBManager.LogOut();
     SceneManager.LoadScene(0);

 }

 public void IncreaseScore()
 {
     DBManager.score++;
     scoreDisplay.text = "score: " + DBManager.score;
 }

I am getting game saved but when I login again the score is still '0' and the score also did not update in my table and I don't know why.