如何使用php从ios应用程序将数据存储在mysql中？

Question

I want to save user registration detail from my ios app (using swift 3) in MySQL using PHP. But it's not working. Here is my code:

registeruser.php

$response = array ();
    if ($_SERVER ['REQUEST_METHOD'] == 'POST') {
    // getting values
    $username = $_POST ["username"];
    $password = $_POST ['password'];
    // including the db operation file
    require_once '../include/DbOperation.php';
    // inserting values
    if ($db->createUser($username, $password)) {
        $response ['error'] = false;
        $response ['message'] = 'user added successfully';
    } else {
        $response ['error'] = true;
        $response ['message'] = ' user not added';
    }
echo json_encode ( $response );
 public function createUser($username, $password)
    {
$stmt = $this->conn->prepare("INSERT INTO registerUser(username, password) values(?, ?)");
        $stmt->bind_param("register", $username, $password);  
        $result = $stmt->execute();
        $stmt->close();
        echo $result;
        if ($result) {
            return true;
        } else {
            return false;
        }
    }

I don't know why it's not working?

the error shown is

Undefined index: Username and password.

Answer 1

public function actionXXX() 
{
    $response = array ();
    if ($_SERVER ['REQUEST_METHOD'] == 'POST') {
        // getting values
        $username = $_POST ["username"];
        $password = $_POST ['password'];
        // including the db operation file
        require_once '../include/DbOperation.php';
        // inserting values
        // $db = new ***
        if ($db->createUser($username, $password)) {
            $response ['error'] = false;
            $response ['message'] = 'user added successfully';
        } else {
            $response ['error'] = true;
            $response ['message'] = 'user not added';
        }
        return json_encode($response);
    }
}
public function createUser($username, $password)
{
    $stmt = $this->conn->prepare("INSERT INTO registerUser(username, password) values(?, ?)");
    $stmt->bind_param("register", $username, $password);
    $result = $stmt->execute();
    $stmt->close();
    if ($result) {
        return true;
    } else {
        return false;
    }
}