json data not showing - php

Question

i'm trying to connect mysql database server xampp to android studio,i wrote php code and when i run the code ,the result not showing anything.
here is my code:
connection.php
<? php
define ('hostname','localhost');
define ('user','root');
define ('password','1993');
define ('dbname','mat');
$connect = mysqli_connect(hostname,user,password,dbname);
$mysqli->query("set character_set_server='utf8'");
$mysqli->query("set NAMES 'utf8'");
?>
php to fetch data from database:
show.php
<?php
if($_SERVER["REQUEST_METHOD"]=="POST"){
include 'connection.php';
ShowMat();
}
function ShowMat()
{
global $connect;
$query = "Select * from mat;";
$result = mysqli_query($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[] = $row;
}
}
header('Content-Type: application/json');
echo json_encode(array("mata"=>$temp_array));
mysqli_close($connect);
}
How can I solve this?

Answer 1

I think your REQUEST_METHOD is GET so your code :
if($_SERVER["REQUEST_METHOD"]=="POST"){
so this condition will fail that is why you are not getting any echo.
You can use POSTMAN to test your apis give it a try its really useful.

Answer 2

You change this line mysqli_fetch_assoc to this line while ($row = mysqli_fetch_array($result))

Answer 3

This line is creating problem :if($_SERVER["REQUEST_METHOD"]=="POST").Check what type of data are you sending.Are you sending raw data or structured data.Try isset($_REQUEST['']). Example :
$action=isset($_REQUEST['action'])?$_REQUEST['action']:"";
switch($action)
{
case "ShowMat":
ShowMat();
}
function ShowMat()
{
// code
}