php ile veri ekleme veri listeleme

<?php

$connection = new mysqli(
    "localhost",
    "root",
    "",
    "test"
);

?>

<?php

include ("database.php");

if ($_POST) {

    $content=$_POST["content"];

    $stmt = $connection->prepare("INSERT INTO post2 (content) VALUES (?)");

    $stmt->bind_param("s", $content);

    $stmt->execute();

    $stmt->close();
}

?>

<form action="" method="POST">
        <div>
            <label for="content">İçerik Metni:</label><br>
            <textarea id="content" name="content" rows="4" cols="50" required></textarea>
        </div>
        <br>
        <button type="submit">Gönder</button>
    </form>

<?php

include("database.php");

$id = intval($_GET['id'] ?? 0);
$sql = "SELECT id, content, created FROM post2 WHERE id = $id";
$result = mysqli_query($connection, $sql);

if ($result) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo htmlspecialchars($row['id']) . "<br>";
        echo htmlspecialchars($row['content']) . "<br>";
        echo htmlspecialchars($row['created']) . "<br>";
    }
}

?>

<?php

include ("database.php");

$sql = "SELECT id, content, created FROM post2";
$result = mysqli_query($connection, $sql);

if ($result) {
    while ($row = mysqli_fetch_assoc($result)) {
        echo htmlspecialchars($row['id']) . "<br>";
        echo htmlspecialchars($row['content']) . "<br>";
        echo htmlspecialchars($row['created']) . "<br>";
    }
}

?>

CREATE TABLE `post2` (
  `id` INT(11) NOT NULL AUTO_INCREMENT,
  `content` TEXT NOT NULL,
  `created` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;