在 PDO PHP 脚本中两次使用相同的 POST 值 | mySQL

Question

第二次使用 POST 值时:supplier，脚本不会写入数据库。如果没有第二个实例，一切都会按预期写入。我究竟做错了什么？

$hostdb = 'localhost';

$namedb = 'dbname';

$userdb = 'username';

$passdb = 'password';

$charset = 'utf8'; 

if (isset($_POST['name'], $_POST['type'] , $_POST['number'] ,$_POST['supplier']  )) {

    // Connect and create the PDO object

    $options = [

        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,

        PDO::ATTR_EMULATE_PREPARES => false,

    ];

    $conn = new PDO("mysql:host=$hostdb;dbname=$namedb;charset=$charset", $userdb, $passdb, $options);

      try{

        $conn->beginTransaction();

    $stmt = $conn->prepare( ' INSERT INTO `Equipment` (name, type, number, supplier, status, managed_by )

VALUES (:name,:type,:number,:supplier,"Ready", :supplier) ' );

    $stmt->execute([

        'name' => $_POST['name'],

        'type' => $_POST['type'],

        'number' => $_POST['number'],

        'supplier' => $_POST['supplier'],

    ]);