try catch

<?php
session_start();
?>
<?php
include('ceklogin.php');
date_default_timezone_set("Asia/Jakarta");
?>

<?php
$Kd_barang=isset($_GET['Kd_barang']) ? $_GET['Kd_barang'] :'';
Include('db_connection.php');
$querybarang=mysql_query("SELECT * FROM tabelbarang where Kd_barang='".$Kd_barang."'");
$databarang=mysql_fetch_array($querybarang);
?>


<?php
    require 'database.php';
    $Kd_barang = 0;
	$barang = 0;

    if ( !empty($_GET['Kd_barang'])) {
        $Kd_barang = $_REQUEST['Kd_barang'];
    }


    if ( !empty($_POST)) {
        // post value
        $Kd_barang = $_POST['Kd_barang'];
		$barang = isset($_GET['barang']) ? $_GET['barang']:null;
         $barang = $_POST['barang'];

        // menghapus data
        $pdo = Database::connect();
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $sql = "DELETE FROM tabelbarang WHERE Kd_barang = ?";
		$sql2 ="ALTER TABLE tabeltransaksi
		        DROP COLUMN '".$barang."'";


		$q = $pdo->prepare($sql);
		$q->execute(array($Kd_barang));
            if ($q == true) {
                try {

		  	    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
				$pdo->beginTransaction();
				$pdo->exec("ALTER TABLE tabeltransaksi DROP '".$barang."'");
		    	$pdo->commit();
				echo "Data berhasil dihapus...";
     				}
			    	catch(PDOException $e)
					     {
				      // roll back transaksi jika error sesuatu
					      $pdo->rollback();

			      echo $sql . "<br>" . $e->getMessage();
						  }

        }


            Database::disconnect();
            header("Location: tampilbarang.php");
        }
?>

<!DOCTYPE html>
<html lang="en">

<head>

    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="">

    <title>Hapus barang</title>

    <!-- Bootstrap Core CSS -->
    <link href="vendor/bootstrap/css/bootstrap.min.css" rel="stylesheet">

    <!-- Theme CSS -->
    <link href="css/clean-blog.min.css" rel="stylesheet">

    <!-- Custom Fonts -->
    <link href="vendor/font-awesome/css/font-awesome.min.css" rel="stylesheet" type="text/css">
    <link href='http://fonts.googleapis.com/css?family=Lora:400,700,400italic,700italic' rel='stylesheet' type='text/css'>
    <link href='http://fonts.googleapis.com/css?family=Open+Sans:300italic,400italic,600italic,700italic,800italic,400,300,600,700,800' rel='stylesheet' type='text/css'>

    <!-- HTML5 Shim and Respond.js IE8 support of HTML5 elements and media queries -->
    <!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
    <!--[if lt IE 9]>
        <script src="https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js"></script>
        <script src="https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js"></script>
    <![endif]-->

</head>

<body>

    <!-- Navigation -->
    <nav class="navbar navbar-default navbar-custom navbar-fixed-top">
        <div class="container-fluid">
            <!-- Brand and toggle get grouped for better mobile display -->
            <div class="navbar-header page-scroll">
                <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
                    <span class="sr-only">Toggle navigation</span>
                    Menu <i class="fa fa-bars"></i>
                </button>
                <a class="navbar-brand" href="index.php">SND Photography</a>
            </div>

            <!-- Collect the nav links, forms, and other content for toggling -->
            <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
                <ul class="nav navbar-nav navbar-right">
                    <li>
                        <a href="index.php">Beranda</a>
                    </li>
                    <li class="dropdown">
                        <a href="#" class="dropdown-toggle" data-toggle="dropdown">Barang</a>
						<ul class="dropdown-menu">
                        <li><a href="tambahbarang.php"><font color="#000000">Tambah Barang</font></a></li>
                        <li><a href="tampilbarang.php"><font color="#000000">Tampil Barang </font></a></li>
                        </ul>
                    </li>
                    <li>
                        <a href="#" class="dropdown-toggle" data-toggle="dropdown">Transaksi</a>
						<ul class="dropdown-menu">
                        <li><a href="tambahtransaksi.php"><font color="#000000">Tambah Transaksi</font></a></li>
                        <li><a href="tampiltransaksi.php"><font color="#000000">Tampil Transaksi </font></a></li>
						</ul>
                    </li>
                    <li>
                        <a href="#" class="dropdown-toggle" data-toggle="dropdown">User</a>
						<ul class="dropdown-menu">
                        <li><a href="tambahadmin.php"><font color="#000000">Tambah User</font></a></li>
                        <li><a href="tampiladmin.php"><font color="#000000">Tampil User</font></a></li>
						</ul>
                    </li>
                    <li>
                        <a href="#" class="dropdown-toggle" data-toggle="dropdown">Laporan</a>
						<ul class="dropdown-menu">
                        <li><a href="laporanbarang.php" target="_blank"><font color="#000000">Laporan Barang</font></a></li>
                        <li><a href="laporantransaksi.php" target="_blank"><font color="#000000">Laporan Transaksi</font></a></li>
                        <li><a href="laporanadmin.php" target="_blank"><font color="#000000">Laporan user</font></a></li>
						</ul>
                    </li>
                    <li>
                        <a href="datamining/index.php" target="_blank">Analisa Apriori</a>
                    </li>

                </ul>
            </div>
            <!-- /.navbar-collapse -->
        </div>
        <!-- /.container -->
    </nav>

    <!-- Page Header -->
    <!-- Set your background image for this header on the line below. -->
    <header class="intro-header" style="background-image: url('img/home-bg.jpg')">
        <div class="container">
            <div class="row">
                <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
                    <div class="site-heading">
                        <h1>Hapus Barang</h1>
                        <hr class="small">
                        <h4><?php echo "Tanggal " . date("d/m/Y") . "<br>"; ?> </h4>
                        <h4><?php echo "Jam " . date("h:i a"); ?> </h4>
                    </div>
                </div>
            </div>
        </div>
    </header>

<div class="container">
<form class="form-horizontal" action="deletebarang.php" method="post">
<label class="control-label">Kode Barang</label>
<div class="controls">
<input name="Kd_barang" id="Kd_barang" type="number" placeholder="Kode Barang" readonly value="<?php echo $databarang['Kd_barang'];?>">
</div>
</div>

<label class="control-label">Barang</label>
<div class="controls">
<input name="barang" id="barang" type="text" placeholder="Barang" readonly value="<?php echo $databarang['barang'];?>">
</div>
</div>

<label class="control-label">Harga Barang</label>
<div class="controls">
<input name="harga" id="harga" type="number" placeholder="Harga" readonly value="<?php echo $databarang['harga'];?>">
</div>
</div>

<label class="control-label">Keterangan</label>
<div class="controls">
<input name="Keterangan" id="Keterangan" type="text" placeholder="Keterangan" readonly value="<?php echo $databarang['Keterangan'];?>">

</div>
</div>
<br />
<div class="form-actions">
<button type="submit" class="btn btn-success">hapus</button>
<a class="btn" href="tampilbarang.php">Kembali</a>
</div>
</form>



</div>
  <!-- Footer -->
    <footer>
        <div class="container">
            <div class="row">
                <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
                    <ul class="list-inline text-center">
                        <li>
                            <a href="https://www.facebook.com/SND-Photography-188259054557713/">
                                <span class="fa-stack fa-lg">
                                    <i class="fa fa-circle fa-stack-2x"></i>
                                    <i class="fa fa-facebook fa-stack-1x fa-inverse"></i>
                                </span>
                            </a>
                        </li>
                    </ul>
                    <p class="copyright text-muted">Copyright &copy; SND Photography 2016</p>
                </div>
            </div>
        </div>
    </footer>

    <!-- jQuery -->
    <script src="vendor/jquery/jquery.min.js"></script>

    <!-- Bootstrap Core JavaScript -->
    <script src="vendor/bootstrap/js/bootstrap.min.js"></script>

    <!-- Contact Form JavaScript -->
    <script src="js/jqBootstrapValidation.js"></script>
    <script src="js/contact_me.js"></script>

    <!-- Theme JavaScript -->
    <script src="js/clean-blog.min.js"></script>

</body>

</html>