无法从android php连接插入MySql Db

Question

I'm making a little MySql Crud using Android-Studio and the data fetching is working just well but I cannot insert into db and I think the problem may be because of lack of permission to write (maybe?).

Anyway, in a given point, the user is at Register.java Activity and presses button to register. This calls the method onClick() on switch case R.id.BtRegs. This calls a registerUser method which calls the ServerRequests class. In the doInBackground I try to connect to my localhost using the IP of my network lan calling the Register.php with POST method. It does not return anything from Register.php. How do I check if it is indeed a lack of permission of some other thing? I think it may be no permission because the same methods used to fetch data worked well.

Here is the part of the code on ServerRequests class which does the connection:

@Override
    protected Void doInBackground(Void... params) {

        Map<String,String> dataToSend = new HashMap<>();


        dataToSend.put("name", user.name);
        dataToSend.put("age", String.valueOf(user.age));
        dataToSend.put("username", user.username);
        dataToSend.put("password", user.password);

        String encodedStr = getEncodedData(dataToSend);
        BufferedReader reader = null;

        try{

            URL url = new URL(SERVER_ADDRESS + "/Register.php");

            HttpURLConnection con = (HttpURLConnection) url.openConnection();

            con.setConnectTimeout(CONNECTION_TIMEOUT);
            con.setReadTimeout(CONNECTION_TIMEOUT);

            con.setRequestMethod("POST");

            con.setDoOutput(true);
            OutputStreamWriter writer = new OutputStreamWriter(con.getOutputStream());

            writer.write(encodedStr);
            writer.flush();

And this is the Register.php which does the MySQL insert:

<?php
$con = mysqli_connect("host", "user", "pass", "db");
$name = $_POST["name"];
$age = $_POST["age"];
$username = $_POST["username"];
$password = $_POST["password"];
$statement = mysqli_prepare($con, "INSERT INTO tabuser (name, age, username, password) VALUES (?,?,?,?) ");
mysqli_stmt_bind_param($statement, "siss", $name, $age, $username, $password);
mysqli_stmt_execute($statement);
mysqli_stmt_close($statement);
mysqli_close($con);
?>

note: Considering SERVER_ADDRESS = "http://192.168.x.x" and $con = mysqli_connect("host", "user", "pass", "db"); is normally set on main proj.

Answer 1

The problem is solved:

As @Redbeard011010 commented, the lack of commit was causing this problem.

So, on the code I added:

$mysqli->autocommit(FALSE);
//do the inserting
if (!$mysqli->commit()) {
print("Transaction commit failed
");
exit();
}

After this, the code is working normally and the data is being inserted into the database. More info here