php 如何查询一个试图

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "database_name";

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}

$viewName = "my_view";
$query = "SELECT * FROM $viewName";

$stmt = $conn->prepare($query);
$stmt->execute();

$results = $stmt->fetchAll(PDO::FETCH_ASSOC);

setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $viewName = "my_view";
    $query = "SELECT * FROM $viewName";

    $stmt = $conn->prepare($query);
    $stmt->execute();

    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);

    foreach ($results as $row) {
        echo "id: " . $row['id'] . "
";
        echo "name: " . $row['name'] . "
";
    }
} catch (PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}