connection.php

<?php
define('hostname', 'localhost');
define('user', 'root');
define('password', '');
define('databaseName', 'tutorial');
$connect = mysqli_connect(hostname, user, password, databaseName);
?>

insertStudent.php

<?php
if($_SERVER["REQUEST_METHOD"]=="POST"){
	require 'connection.php';
	createStudent();
}
function createStudent()
{
	global $connect;
	
	$firstname = $_POST["firstname"];	
	$lastname = $_POST["lastname"];
	$age = $_POST["age"];
	
	$query = " Insert into student(firstname,lastname,age) values ('$firstname','$lastname','$age');";
	
	mysqli_query($connect, $query) or die (mysqli_error($connect));
	mysqli_close($connect);
	
}
?>

showStudents.php

<?php
if($_SERVER["REQUEST_METHOD"]=="POST"){
	include 'connection.php';
	showStudent();
}
function showStudent()
{
	global $connect;
	
	$query = " Select * FROM STUDENT; ";
	
	$result = mysqli_query($connect, $query);
	$number_of_rows = mysqli_num_rows($result);
	
	$temp_array  = array();
	
	if($number_of_rows > 0) {
		while ($row = mysqli_fetch_assoc($result)) {
			$temp_array[] = $row;
		}
	}
	
	header('Content-Type: application/json');
	echo json_encode(array("students"=>$temp_array));
	mysqli_close($connect);
	
}
?>

tutorial

<?php
if($_SERVER["REQUEST_METHOD"]=="POST"){
	require 'connection.php';
	createStudent();
}
function createStudent()
{
	global $connect;
	
	$firstname = $_POST["firstname"];	
	$lastname = $_POST["lastname"];
	$age = $_POST["age"];
	
	$query = " Insert into student(firstname,lastname,age) values ('$firstname','$lastname','$age');";
	
	mysqli_query($connect, $query) or die (mysqli_error($connect));
	mysqli_close($connect);
	
}
?>
<?php
if($_SERVER["REQUEST_METHOD"]=="POST"){
	include 'connection.php';
	showStudent();
}
function showStudent()
{
	global $connect;
	
	$query = " Select * FROM STUDENT; ";
	
	$result = mysqli_query($connect, $query);
	$number_of_rows = mysqli_num_rows($result);
	
	$temp_array  = array();
	
	if($number_of_rows > 0) {
		while ($row = mysqli_fetch_assoc($result)) {
			$temp_array[] = $row;
		}
	}
	
	header('Content-Type: application/json');
	echo json_encode(array("students"=>$temp_array));
	mysqli_close($connect);
	
}
?>




<?php
define('hostname', 'localhost');
define('user', 'root');
define('password', '');
define('databaseName', 'tutorial');
$connect = mysqli_connect(hostname, user, password, databaseName);
?>