Mini Shell

<?php
    include 'db/database.php'; 
    $name = $_POST['name'];
    $last_name = $_POST['last_name'];
    $username = $_POST['username'];
    $password = $_POST['password'];
    $login_status = $_POST['login_status'];
   

    
 
    //เช็ค Username ซ้ำกันหรือไม่
    $sql_user = "SELECT username FROM user WHERE username='$username'";
    $result_user = mysqli_query($link, $sql_user);
    $is_user = mysqli_num_rows($result_user);
    if ($is_user == 1) {
        header('Content-Type: application/json');
        $errors = "Username มีคนใช้แล้ว กรุณาเปลี่ยน Username ใหม่" . mysqli_error($link);
        echo json_encode(array('status' => 'danger','message' => $errors));
        exit;
    }
    
    //เข้ารหัส Password
    $salt = 'tikde78uj4ujuhlaoikiksakei896';
    $hash_password = hash_hmac('sha256', $password, $salt);
  
    
    $sql = "INSERT INTO `user` (`name`,`last_name`,`username`,`password`,`login_status`) VALUES 
          ('$name','$last_name','$username','$hash_password','$login_status')";
    $result = mysqli_query($link, $sql);
    
    if ($result) {
        header('Content-Type: application/json');
        echo json_encode(array('status' => 'success','message' => 'บันทึกข้อมูลเรียบร้อยแล้ว'));
    } else {
        header('Content-Type: application/json');
        $errors = "เกิดข้อผิดผลาดไม่สามารถบันทึกข้อมูลได้" . mysqli_error($link);
        echo json_encode(array('status' => 'danger','message' => $errors));
    }