fetch-single.php

<?php
 header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Headers: access');
header('Access-Control-Allow-Methods:POST,GET,PUT,DELETE');
header('Content-Type: application/json; charset=UTF-8');
header('Access-Control-Allow-Headers: content-type, Access-Control-Allow-Headers, Authorization, X-Requested-With');
header('Access-Control-Allow-Credentials: true');
// Importing DBConfig.php file.
include 'db.php';
//fetching all students...
$json = file_get_contents('php://input');
// decoding the received JSON and store into $obj variable.
$obj = json_decode($json,true);
$id = $obj['id'];

$result = $con->query("SELECT * FROM crud WHERE id = '$id' ");
if ($result->num_rows > 0) {
   $cat_err = array();
   while ($row = $result->fetch_assoc()){
      extract($row);
        $category = array(
         "id" => $id,
         "firstname" => $firstname,
         "lastname" => $lastname,
         "age" => $age
        );
        array_push($cat_err, $category);
    }
   // set response code - 200 OK
   http_response_code(200);
    // show products data in json format
    // echo json_encode($cat_err);
   echo json_encode(array("status"=> "success","user" => $cat_err));
}else{
   // set response code - 404 Not found
   http_response_code(404);
   // tell the user no products found
   echo json_encode(
      array("message" => "No category found.")
   );
}
mysqli_close($con);
?>