crud.php

<?php

	include 'config.php';

	$data = json_decode(file_get_contents("php://input"));

	$request_type = $data->request_type;

	// Get all records
	if($request_type == 1){
	 $sel = mysqli_query($con,"select * from users");
	 $data = array();

	 while ($row = mysqli_fetch_array($sel)) {
	  $data[] = array("id"=>$row['id'],"fname"=>$row['fname'],"lname"=>$row['lname'],"username"=>$row['username']); 
	 }
	 echo json_encode($data);
	}

	// Insert record
	if($request_type == 2){
	 $fname = $data->fname;
	 $lname = $data->lname;
	 $username = $data->username;

	 mysqli_query($con,"insert into users(fname,lname,username) values('".$fname."','".$lname."','".$username."')");
	 $lastinsert_id = mysqli_insert_id($con);

	 $return_arr[] = array("id"=>$lastinsert_id,"fname"=>$fname,"lname"=>$lname,"username"=>$username);
	 echo json_encode($return_arr);
	}

	// Delete record
	if($request_type == 3){
	 $userid = $data->userid;

	 mysqli_query($con,"delete from users where id=".$userid);
	 echo 1;
	}

?>