edit.php ( Cara CRUD )

<?php
    require_once("koneksi.php");
    if (isset($_POST['submit'])) {
        $sql = $conn->prepare("UPDATE tbl_mahasiswa SET namamhs=? , alamatmhs=? , teleponmhs=? , jurusanmhs=? WHERE nimmhs=?");
        $namamhs=$_POST['namamhs'];
        $alamatmhs = $_POST['alamatmhs'];
        $teleponmhs= $_POST['teleponmhs'];
        $jurusanmhs= $_POST['jurusanmhs'];
        $sql->bind_param("sssss",$namamhs, $alamatmhs, $teleponmhs, $jurusanmhs,$_GET["nimmhs"]);
        if($sql->execute()) {
            $success_message = "Update Data Berhasil";
        } else {
            $error_message = "Ada masalah update data";
        }

    }
    $sql = $conn->prepare("SELECT * FROM tbl_mahasiswa WHERE nimmhs=?");
    $sql->bind_param("s",$_GET["nimmhs"]);
    $sql->execute();
    $result = $sql->get_result();
    if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
    }
    $conn->close();
?>
<html>
<head>
<link href="style.css" rel="stylesheet" type="text/css" />
<style>
.tbl-qa{border-spacing:0px;border-radius:4px;border:#6ab5b9 1px solid;}
</style>
<title>JavanetMedia - Edit Mahasiswa </title>
</head>
<body>
<?php if(!empty($success_message)) { ?>
<div class="success message"><?php echo $success_message; ?></div>
<?php } if(!empty($error_message)) { ?>
<div class="error message"><?php echo $error_message; ?></div>
<?php } ?>
<form name="frmUser" method="post" action="">
<div class="button_link"><a href="index.php" > List Mahasiswa </a></div>
<table border="0" cellpadding="10" cellspacing="0" width="500" align="center" class="tbl-qa">
    <thead>
        <tr>
            <th colspan="2" class="table-header">Edit Data Mahasiswa</th>
        </tr>
    </thead>
    <tbody>
        <tr class="table-row">
            <td><label>Nama</label></td>
            <td><input type="text" name="namamhs" class="txtField" value="<?php echo $row["namamhs"]?>"></td>
        </tr>
        <tr class="table-row">
            <td><label>Alamat</label></td>
            <td><input type="text" name="alamatmhs" class="txtField" value="<?php echo $row["alamatmhs"]?>"></td>
        </tr>
        <tr class="table-row">
            <td><label>Telepon</label></td>
            <td><input type="text" name="teleponmhs" class="txtField" value="<?php echo $row["teleponmhs"]?>"></td>
        </tr>
        <tr class="table-row">
            <td><label>Jurusan</label></td>
            <td><input type="text" name="jurusanmhs" class="txtField" value="<?php echo $row["jurusanmhs"]?>"></td>
        </tr>
        <tr class="table-row">
            <td colspan="2"><input type="submit"  name="submit" value="Submit" class="demo-form-submit"></td>
        </tr>
    </tbody>
</table>
</form>
</body>
</html>