Question

我试图在php中创建一个工作更新页面。我相信我的语法没有问题，但我一直收到错误＆＃34;未定义的变量＆＃34;对于我在输入字段中输入的值。请帮忙！

<?php
  require("connect.php");

  if (isset($_POST['submit'])) {
    $udpdateQuery = "UPDATE league SET `LeagueName` = :name, `LeagueCountry` = :country, `LeagueSize` = :size WHERE `LeagueID` = :leagueID";
    $stmt3 = $con->prepare($udpdateQuery);
    $stmt3->execute(array('name' => $_POST['l_name'], 'country' => $_POST['l_country'], 'size' => $_POST['l_size']));
    $stmt4->closeCursor();
  }

  if (isset($_GET['LeagueID'])) {
    $valuesQuery = "SELECT `LeagueName`, `LeagueCountry`, `LeagueSize` FROM league WHERE `LeagueID` = :leagueID";
    $stmt4 = $con->prepare($valuesQuery);
    $stmt4->execute(array('leagueID' => $_GET['LeagueID']));
    $result = $stmt4->fetchAll();
    $stmt4->closeCursor();

    foreach ($result as $r) {
      $name = $r['LeagueName'];
      $country = $r['LeagueCountry'];
      $size = $r['LeagueSize'];
    }
  }
  ?>
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>League</title>
    <link rel="stylesheet" type="text/css" href="css/style.css">
    <link href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700" rel="stylesheet">
  </head>
  <body>
        <div class="wrapper">
        <form class="add" action="" method="post">
          <label>League Name</label>
          <input type="text" name="l_name" value="<?=$name?>" required><br>

          <label>League Country</label>
          <input type="text" name="l_country" value="<?=$country?>" required><br>

          <label>League Size</label>
          <input type="text" name="l_size" value="<?=$size?>" required><br>

          <input id="submit" name="submit" type="submit" value="Submit">
        </form>

        <?php include('home.php'); ?>

      </div>
      <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
      <script type="text/javascript" src="resources/js/main.js"></script>
  </body>
</html>

Answer 1

第一次运行代码时，它只会进入$_GET部分。提交后，它只会进入$_POST部分。这就是它显示错误的原因，因为没有定义变量。

你需要：

为您的LeagueID添加隐藏字段：

<input type="hidden" name="l_id" value="<?=$id?>"><br>

修正您的更新：

$stmt3->execute(array('name' => $_POST['l_name'], 'country' => $_POST['l_country'], 'size' => $_POST['l_size'], 'leagueID' => $_POST['l_id']));

根据获取或发布的内容正确创建变量：

if (isset($_POST['submit'])) {
    $id = $_POST['l_id'];
    $name = $_POST['l_name'];
    $country = $_POST['l_country'];
    $size = $_POST['l_size'];

...

if (isset($_GET['LeagueID'])) {
...
    foreach ($result as $r) {
        $id = $_GET['LeagueID'];
        $name = $r['LeagueName'];
        $country = $r['LeagueCountry'];
        $size = $r['LeagueSize'];
    }

Answer 2

看起来你可能会遇到一些问题。

在您的第一个if语句中，您正在关闭错误的光标：
```
$stmt4->closeCursor();
```
这个尚未定义;这应该是$stmt3
表单中的变量$name，$country和$size仅在第二个if块中定义（对于$_GET，< em> if 有一个LeagueID集合并且有结果（））。如果这些都不是真的，那么变量就不会被定义 - 当你提交表格时，两者都不是真的。

为了帮助防止这种情况，请在if块之外定义它们：
```
$name = '';
$country = '';
$size = '';
if (isset($_GET['LeagueID'])) {
```
然后，更新您的表单，以便在提交时传递LeagueID：
```
<form action="/path?LeagueID=<?= htmlentities($_GET['LeagueID']) ?>" method="post" class="add">
```

插入语句不起作用，未定义变量

2 个答案: