<?php
$urlTemperature = $_GET['temp'];

$servername = 'secret';
$username = 'secret';
$password = 'secret';

$conn = new mysqli($servername, $username, $password);
$conn->select_db("id2058220_temperaturedata");

$lastTemperature = $conn->query("SELECT temperature_value FROM temperatures ORDER BY id DESC LIMIT 1");
$currentTemperature = $lastTemperature->fetch_assoc()["temperature_value"];

if (isset($urlTemperature)) {
    if ($urlTemperature != $currentTemperature) {
        $insertTemperatures = "INSERT INTO `temperatures`(`temperature_value`) VALUES ($urlTemperature)";
        $conn->query($insertTemperatures);
    }
} else {
    echo "<script>setInterval(function() {location.reload()}, 1000)</script>
          <link href='https://fonts.googleapis.com/css?family=Inconsolata' rel='stylesheet'>
          <style>
          .temp-container {
            display: flex;
            justify-content: center;
            align-items: center;
          }

          .temp-text {
            font-family: 'Inconsolata', monospace;
          }

          </style>
     <div class='temp-container'>
       <h1 class='temp-text'>Температура в помещении $currentTemperature °С</h1>
     </div>";
}
?>