Php 数组不会打印行数据

我得到了这个简单的PHP代码来打印数据库中的一列，但它并没有正常工作。有什么好主意吗？ 我试着处理if语句中的while循环，但没有成功 我试图让阵列打印的内容如下：

---

你做错了，应该是这样

一,。选择多行

或

<?php
$input = $_POST['input'];
$servername = "localhost";
$username = "hawk_manager";
$password = "hawk_eyes";

try {
  $pdo = new PDO("mysql:host=$servername;dbname=HawkCenter", $username, $password);
  // set the PDO error mode to exception
  $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
  
} catch(PDOException $e) {
  echo "Connection failed: " . $e->getMessage();
}
    
if ($input == "RoomNumber") {
    $query = 'SELECT RoomNumber FROM rooms';
    $statement=$pdo->prepare($query);
    $statement->execute();
    $roomnumbers=$statement->fetchAll(PDO::FETCH_ASSOC);
    $statement->closeCursor();
    
    while( $roomnumbers=$statement->fetchAll(PDO::FETCH_ASSOC)){
        
        echo "{$statement['RoomNumber']}";
    }
}

$conn = null;

    
    ?> 

$data = $pdo->query("SELECT RoomNumber FROM rooms")->fetchAll(PDO::FETCH_ASSOC);
foreach ($data as $row) {
    echo $row['RoomNumber ']."<br />\n";
}

$stmt = $pdo->prepare("SELECT RoomNumber FROM rooms WHERE id=?");
$stmt->execute([$id]); 
$user = $stmt->fetch();

$stmt = $pdo->prepare("$stmt = $pdo->prepare("SELECT RoomNumber FROM rooms LIMIT :limit, :offset");
$stmt->execute(['limit' => $limit, 'offset' => $offset]); 
$data = $stmt->fetchAll();
foreach ($data as $row) {
    echo $row['RoomNumber']."<br />\n";
}