How an Arduino can pass it's readings to a PHP code? (Web Client using GET)

Hello,
the aim of my project is to display temperature and humidity on a web page.
Whereas arduino successfully reads values off the sensor, php seems to fail to receive and pass them to a web page.

Detailed information:

What I am using:
Mega 2560
Ethernet shield (successfully set up, no problems can be coming from here)
DHT22 sensor (no problems can be coming from here either, as Serial Monitor logs the temperature)
PHP
SQLite for database purposes

My arduino code:

// Example web client using the Ethernet shield

// Include libraries
#include <SPI.h>
#include <Ethernet.h>
#include <dht.h>

dht DHT;
#define DHT22_PIN 2

// Enter a MAC address for your controller below.
byte mac[] = { 0x94, 0x57, 0xA5, 0xE0, 0x43, 0x4B };

// Set the static IP address for your board
IPAddress ip(172,17,55,19);

// IP address of your computer
IPAddress server(172,17,55,30);

// Initialize the Ethernet client
EthernetClient client;

void setup() {
  
  // Open serial communications
  Serial.begin(115200);

  // Start the Ethernet connection
  if (Ethernet.begin(mac) == 0){
    Serial.println("Failed to configure Ethernet using DHCP");
    Ethernet.begin(mac, ip);
  }
  
  // Display IP
  Serial.print("IP address: ");
  Serial.println(Ethernet.localIP());
  
  // Give the Ethernet shield a second to initialize
  delay(1000);
  Serial.println("Connecting...");
  
}

void loop()
{
  int chk = DHT.read22(DHT22_PIN);
  
  // Measure the humidity and temperature 
  float h = DHT.humidity ;
  float t = DHT.temperature ; 
  
  // Trasnform to a String 
  String hum = String ( (int) h);
  String temp = String ( (int) t);
  
  // Print on Serial monitor  
  Serial.println("Humidity: "  + hum);
  Serial.println("Temperature: " + temp);
    
  // Connect to server
  if (client.connect(server, 80)) {
    if (client.connected()) {
      Serial.println("connected");
    
      // Make a HTTP request:
      client.println("GET /datalogger.php?temp=" + temp + "&hum=" + hum + " HTTP/1.1");
      client.println("Host: 172.17.55.254");
      client.println("Connection: close");
      client.println();
    } 
    else {
      // If you didn't get a connection to the server
      Serial.println("connection failed");
    }
  
    // Read the answer
    while (client.connected()) {
      while (client.available()) {
      char c = client.read();
      Serial.print(c);
      }
    }

    // If the server's disconnected, stop the client:
    if (!client.connected()) {
      Serial.println();
      Serial.println("disconnecting.");
      client.stop();
    }
    
  }
  // Repeat every second
  delay(1000);
}

MY datalogger.php code that is supposed to receive the values via “GET” and log them into a database.db and a web page

<?php
	// Checking that data is present
	//Arduino code can be found in htdocs/datablogger/code
	if (isset($_GET["temp"]) && isset($_GET["hum"])) 
		print ("data");
	else 
		print ("No Data was Received");
	// Getting the data
	$temperature = ($_GET["temp"]);
	$humidity = ($_GET["hum"]);	
	
	//opening the database 
	$db = new PDO('sqlite:database.db');
	
	//creating the database
    $db->exec("CREATE TABLE measurments (Id INTEGER PRIMARY KEY,timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL, temperature INTEGER, humidity INTEGER )");   

	//inserting data
    $db->exec("INSERT INTO measurments (temperature, humidity) VALUES ('$temperature','$humidity');");
	
	//outputting data into the html 
    print "<table border=1>";
    print "<tr><td>Id</td><td>Time</td><td>Temperature</td><td>Humidity</td></tr>";
    $result = $db->query('SELECT * FROM measurments');
    foreach($result as $row)
    {
      print "<tr><td>".$row['Id']."</td>";
      print "<td>".$row['timestamp']."</td>";
      print "<td>".$row['temperature']."</td>";
      print "<td>".$row['humidity']."</td></tr>";
    }
    print "</table>";
	
	// closing the database connection
    $db = NULL;
?>

The error message I keep on receiving when I’m typing this http://localhost/datablogger/datalogger.php into my web browser

No Data was Received
Notice: Undefined index: temp in C:\Apache24\htdocs\datablogger\datalogger.php on line 9

Notice: Undefined index: hum in C:\Apache24\htdocs\datablogger\datalogger.php on line 10
and a little table as described in my html code but without humidity and temperature values.

I examined that if I search http://localhost/datablogger/datalogger.php?temp=20&hum=40 and manually set the temperature and humidity values I successfully receive the table with them.

Therefore, How can I make Arduino transfer his temperature and humidity values to the PHP code?

Any help will be much appreciated,
Nat.