log.php

<?php
  $url = getenv('JAWSDB_URL');
  $dbparts = parse_url($url);

  $hostname = $dbparts['host'];
  $username = $dbparts['user'];
  $password = $dbparts['pass'];
  $database = ltrim($dbparts['path'],'/');

  // Create connection
  $conn = new mysqli($hostname, $username, $password, $database);

  // Check connection
  if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
  }

  echo "Connection was successfully established!";

  $randomText = generateRandomString();
  $insert_log = "INSERT INTO tbl_log(file_name) VALUES('{$randomText}')";

  $conn->query($insert_log);

  mysqli_close($conn);

  function generateRandomString($length = 10) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
  }