handle player id from server at login or register

Assets/Scripts/Login/Login.cs

@@ -76,9 +76,10 @@ public class Login : MonoBehaviour {
             errorText.text = "There was an error logging in " + www.error;
         }
         string result = www.downloadHandler.text;
-        if (result.Equals("Success")) {
+        if (int.TryParse(www.downloadHandler.text, out int userId)) { 
             errorColor.a = 0;
             errorText.color = errorColor;
+            PlayerPrefs.SetInt("UserId", userId);
             // load next scene
             SceneManager.LoadScene("MainMenu");
         } else {

Assets/Scripts/Login/Register.cs

@@ -94,9 +94,10 @@ public class Register : MonoBehaviour {
         }
 
         string result = www.downloadHandler.text;
-        if (result == "Success") {
+        if (int.TryParse(www.downloadHandler.text, out int userId)) {
             errorColor.a = 0;
             errorText.color = errorColor;
+            PlayerPrefs.SetInt("UserId", userId);
             SceneManager.LoadScene("MainMenu");
         } else {
             errorText.text = "Failed to register, username/email already exists"; // be more helpful, get message from sever if it is username or email 

Assets/Scripts/MainMenu.cs

@@ -18,4 +18,8 @@ public class MainMenu : MonoBehaviour
     private void startGameAction() {
         throw new NotImplementedException();
     }
+
+    private void getGames() {
+
+    }
 }

dbFiles/Login.php

@@ -21,7 +21,8 @@
 	$sql = "SELECT id FROM users WHERE username = '$username' AND password = '$password'";
 	$result = $conn->query($sql);
 	if ($result->num_rows == 1) {
-		echo "Success";
+		$data = $result->fetch_assoc();
+		echo $data['id'];
 	} else {
 		echo "Error while logging in user " . $conn->error;
 	}

dbFiles/Register.php

@@ -21,7 +21,7 @@
 	
 	$sql = "INSERT INTO users (username, password, email) VALUES ('$newUsername', '$newPassword', '$newEmail')";
 	if ($conn->query($sql) === true) {
-		echo "Success";
+		echo $conn->insert_id;
 	} else {
 		echo "Error while registering new user " . $conn->error;
 	}