Response from database is not received to php file - php

Question

I have been trying to build a register and login android app using php and mysql with android studio. It appears that the values are being entered to the databse but it is not giving a response back. Table name is harry and php file is:
<?php
define('DBUSER', 'id650955_gokulm100');
define('DBPASS', 'gokulm100');
define('DBHOST', 'localhost');
define('DBNAME', 'id650955_harry');
$conn = new mysqli(DBHOST, DBUSER, DBPASS, DBNAME);
if (!$conn) {
die('error connecting to database');
}
echo 'you have created case';
if(isset($_POST["username"]) && isset($_POST["email"]) && isset($_POST["phone"]) && isset($_POST["password"]))
{
$username = $_POST["username"];
$email = $_POST["email"];
$phone = $_POST["phone"];
$password = $_POST["password"];
$statement = mysqli_prepare($conn, "INSERT INTO harry (username, email, phone, password) VALUES (?, ?, ?, ?)");
mysqli_stmt_bind_param($statement, "ssis", $username, $email, $phone, $password);
mysqli_stmt_execute($statement);
$response = array();
$response["success"] = 1;
echo json_encode($response);
}
else{
echo "not set";
}
?>

Answer 1

assuming that the data is inserted to the database you need to look at your output, it looks like you're sending json text via json_encode and in the same time echo a string "you have created case"
so your output will be a mix of simple characters and some json string. which probably send a parsing error to the callback in the android side of the code.
first you should add a header that indicates the you will be returning json code at the top of the file
header("Content-Type: application/json",true);
then change all your output to be json , any
echo "str";
should be
echo json_encode(array("message"=>"str"));
then see if you still don't get any message back.