index.php

<?php
$servername = "127.0.0.1";
$dbname = "neridaar";
$username = "ID";
$password = "MDP";

    $bdd = new PDO("mysql:host=$servername;port=3306;dbname=$dbname; charset=utf8", $username, $password, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
    $articles = $bdd->query('SELECT * FROM articles ORDER BY date_time_publication DESC');

?>

<!DOCTYPE html>
<html lang="fr">
<head>
    <meta charset="UTF-8">
    <title>Site Neridaar</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>
    <link rel="stylesheet" href="../css/styles.css">
</head>
<body>
    <nav class="navbar navbar-expand-md bg-dark navbar-dark sticky-top">
      <a class="navbar-brand" href="#">Neridaar</a>
      <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navb" aria-expanded="true">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div id="navb" class="navbar-collapse collapse hide">
        <ul class="navbar-nav">
          <li class="nav-item active">
            <a class="nav-link" href="../html/index.php">Accueil</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="../html/autre.php">Autre</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="../html/article.php">Article</a>
          </li>
        </ul>

        <ul class="nav navbar-nav ml-auto">
          <li class="nav-item">
            <a class="nav-link" href="../html/connexion.php"><span class="fas fa-sign-in-alt"></span> Login</a>
          </li>
        </ul>
      </div>
    </nav>


<ul>
      <?php while($a = $articles->fetch()) { ?>
      <li><a href="article.php?id=<?= $a['id'] ?>"><?= $a['titre'] ?></a></li>
      <?php } ?>
</ul>


</body>
</html>