这个发布表单更新Php mysql有什么问题?

这个发布表单更新Php mysql有什么问题?,php,mysql,Php,Mysql,为什么不更新数据库 <?php ob_start(); session_start(); require_once 'dbconnect.php'; if( !isset($_SESSION['user']) ) { header("Location: index.php"); exit; } $res=mysql_query("SELECT * FROM users WHERE userId=".$_SESSION['user']); $userRow=mysql_fetch_arra

为什么不更新数据库

<?php
ob_start();
session_start();
require_once 'dbconnect.php';

if( !isset($_SESSION['user']) ) {
header("Location: index.php");
exit;
}
$res=mysql_query("SELECT * FROM users WHERE userId=".$_SESSION['user']);
$userRow=mysql_fetch_array($res);

$Nname = $_POST['name'];
$Nemail = $_POST['email'];
$Nlocation = $_POST['location'];

$sql = "UPDATE users SET userName = '$Nname', userEmail = '$Nemail',      userLocation = '$Nlocation' WHERE userId=".$_SESSION['user'];
/*if(! $sql ) {
           die('Could not update data: ' . mysql_error());
        }
        echo "Updated data successfully\n";
 */
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Profiel <?php echo $userRow['userName'] ?></title>
<link rel="stylesheet" href="css/style.css" type="text/css" />
<link href="https://fonts.googleapis.com/css?family=Raleway:400, 600"    rel="stylesheet">
</head>
<body>
<header>
<h1>Profiel</h1>
</header>
<nav>
  <a href="/home.php">Home</a>
  <a href="/profile.php">Profiel</a>
  <a href="/logout.php?logout">Log uit</a>
</nav>
<div class="content">
  <h1>Welkom <?php echo $userRow['userName'] ?></h1>
  <?php/* switch (true) {
    case isset($_GET['change']):*/?>
    <form class="update" action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']); ?>" method="post">
    <table>
      <p><tr><td></td><td>Oud</td><td>Nieuw</td></tr></p>
      <p><tr><td>Naam: </td><td><?php echo $userRow['userName'] ?></td><td>    <input type="text" name="name" value="<?php echo $userRow['userName'] ?>"></td></tr></p>
      <p><tr><td>Email: </td><td><?php echo $userRow['userEmail'] ?></td><td><input type="text" name="email" value="<?php echo $userRow['userEmail'] ?>"></td></tr></p>
      <p><tr><td>Werk Locatie: </td><td><?php echo $userRow['userLocation'] ?></td><td><input type="text" name="location" value="<?php echo $userRow['userLocation'] ?>"></td></tr></p>
    </table>
    <button type="submit" name="button">Opslaan</button>
  </form>
    <?php /*break;
    default:?>
    <table>
      <p><tr><td>Naam: </td><td><?php echo $userRow['userName'] ?></td></tr></p>
      <p><tr><td>Email: </td><td><?php echo $userRow['userEmail'] ?></td></tr></p>
      <p><tr><td>Werk Locatie: </td><td><?php echo $userRow['userLocation'] ?></td></tr></p>
    </table>
    <a href="/profile.php?change">veranderen</a>
    <?php echo $Nname; ?>
    <?php break;
  }*/?>
</div>

Profiel
Profiel
韦尔科姆

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沃克地点:

我不明白为什么它不更新数据库,我尝试了一切。
谢谢你的帮助。数据库连接良好。但是我不知道我是如何将更新发送到我的数据库的,我不明白。有人能告诉我该怎么做吗?

您从未连接到数据库并执行查询。说。即使是这样也不安全!步骤1,连接到数据库。2、展示形式。3检查表单是否已提交,4定义SQL查询,5执行查询