我的代碼：<?phptry {$t = '040485c4-2eba-11e9-8e3c-0231844357e8';if (array_key_exists('t', $_REQUEST)) {  $t = $_REQUEST["t"];}if (!isset($_COOKIE['writer'])) {  header("Location: xxx");  return 0;}$writer = $_COOKIE['writer'];$dbhost = $_SERVER['RDS_HOSTNAME'];$dbport = $_SERVER['RDS_PORT'];$dbname = $_SERVER['RDS_DB_NAME'];$charset = 'utf8' ;$dsn = "mysql:host={$dbhost};port={$dbport};dbname={$dbname};charset={$charset}";$username = $_SERVER['RDS_USERNAME'];$password = $_SERVER['RDS_PASSWORD'];$pdo = new PDO($dsn, $username, $password);$stmt = $pdo->prepare("select writer from mydbtbl where writer=? and t=?");$stmt->execute(array($writer, $t));$num = $stmt->fetch(PDO::FETCH_NUM);if ($num < 1) {  header("Location: login.php");  return 0;}$dbMsg = "Authorized";$dbname = 'imgs';$dsn = "mysql:host={$dbhost};port={$dbport};dbname={$dbname};charset={$charset}";$pdo = new PDO($dsn, $username, $password);if (isset($_FILES['filename'])) {  $name = $_FILES['filename']['name'];  // set path of uploaded file  $path = "./".basename($_FILES['filename']['name']);   // move file to current directory  move_uploaded_file($_FILES['filename']['tmp_name'], $path);  // get file contents  $data = file_get_contents($path, NULL, NULL, 0, 60000);      $stmt = $pdo->prepare("INSERT INTO file (contents, filename, t) values (?,?,?)");  $stmt->execute(array    ($data,     $name,     $t)  );  $dbMsg = "Added the file to the repository"; // delete the file unlink($path);}} catch (Exception $e) {  $dbMsg = "exception: " . $e->getMessage();}在代碼中，您將看到第一部分是用于進行身份驗證的。然后，在img模式上創(chuàng)建一個新的PDO對象，然后在該文件中執(zhí)行查詢。稍后，在我打印$ dbMsg的地方，它說的是“已將文件添加到存儲庫”。但是，當我查詢數(shù)據(jù)庫（使用MySQL Workbench的Amazon AWS上的MySQL）時，沒有插入任何內(nèi)容。我不明白為什么如果什么也沒插入，卻沒有收到錯誤消息。如果顯示“已將文件添加到存儲庫”，這是否表示插入成功？我唯一能想到的是為此使用不同的架構(gòu)來處理問題。我對ebdb的所有插入操作都正常