用php编辑/更新行不起作用/未定义变量

mmvthczy 于 2021-06-21 发布在 Mysql

关注(0)|答案(3)|浏览(439)

我的代码有问题：
在编辑页面上，我想向用户显示输入框中的上一个值。
但关于这个值，我一直得到的一个错误是：

注意：未定义变量：gebruikers\u naam在c:\xampp\htdocs\website\u herkansing\edit\u gebruiker.php第72行**

我想这辆车出了点问题 isset/submit 但我就是搞不懂。。
这是我正在使用的代码

<?php

session_start();

define('DB_NAME', 'ochtendgloren');
$servername = "localhost";
$username = "root";
$password = "";
$db = "ochtendgloren";
$tbl = "members";

// Create connection
$conn = new mysqli($servername, $username, $password, $db);
//Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

if (isset($_POST['submit']))
{
    $gebruikers_naam = mysqli_real_escape_string($db, $_POST['gebruikers_naam']);

    htmlentities($gebruikers_naam);

    $id = $_GET['id'];

    $query = "UPDATE members 
    SET gebruikers_naam = '$gebruikers_naam'
    WHERE id = '$id' " ;

    $result = $conn->query($query);

    if($result){
        echo ("<SCRIPT LANGUAGE='JavaScript'>
    window.alert('edit succesvol!')
    window.location.href='admin_members.php';
    </SCRIPT>");
    } 
}
?>

<html>
<head>
    <link rel="stylesheet" href="boekingsform.css">
    <link  rel="stylesheet" href="https://fonts.googleapis.com/css?family=Abel">
</head>

<div class="boeken">
    <h1>Wijzig hier de gebruiker</h1>
    <form action="editrij.php?id=<?= $id ?>"  method="post" >
        <div class="row">
            <div class="col-25">
                <label for="gebruikers_naam"> vul hier de nieuwe gebruikers naam in: </label>
            </div></div>
        <br>
    <div class="row">
        <div class="col-75">
            <input type="text" name="voornaam" required="required" value="<?= $gebruikers_naam['gebruikers_naam'] ?>"/>
        </div>
    </div>
<br>
    <input type="submit" value="submit" name="submit" />
    </form>
</div>
</html>

mysql php row Edit

来源：https://stackoverflow.com/questions/50816727/edit-update-row-with-php-doesnt-work-undefined-variable

3条答案

按热度按时间

ogq8wdun1#

我认为这个问题与你的变量用法和输入框的名称有关 gebruikers_naam 在线：

<input type="text" name="voornaam" required="required" value="<?= $gebruikers_naam['gebruikers_naam'] ?>"/>

你可以用 $gebruikers_naam 只打印名字。在if子句中使用全局变量之前，还必须先指定它。只分配空值 $gebruikers_naam = ""; 在变量声明之后。

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jdg4fx2g2#

仍然不能完全确定代码的“流”是否有意义，但以下内容应该会有所帮助：

<?php
session_start();

//define('DB_NAME', 'ochtendgloren'); // not used in your code, commented out
$servername = "localhost";
$username = "root";
$password = "";
$db = "ochtendgloren";
$tbl = "members";

// Create connection
$conn = new mysqli($servername, $username, $password, $db);
//Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

if (isset($_POST['submit']))
{
    if(isset($_POST['gebruikers_naam']) && !empty($_POST['gebruikers_naam'])) { // added condition: we need a 'gebruikers_naam'
    $gebruikers_naam = mysqli_real_escape_string($conn, $_POST['gebruikers_naam']);     // changed $db to $conn

    // the return value (encoded string) of htmlentities is not used in your code
    // so commented it out
    //htmlentities($gebruikers_naam); 

    $id = $_GET['id'];

    $query = "UPDATE members 
    SET gebruikers_naam = '$gebruikers_naam'
    WHERE id = '$id' " ;

    $result = $conn->query($query);
    }

    if($result){
        echo ("<SCRIPT LANGUAGE='JavaScript'>
    window.alert('edit succesvol!')
    window.location.href='admin_members.php';
    </SCRIPT>");
    } else {                                                // added else {} statement
    echo "<script> alert('Error: could not update the database'); </script>"; // added: error message
    }       
}
?>

<html>
<head>
    <link rel="stylesheet" href="boekingsform.css">
    <link  rel="stylesheet" href="https://fonts.googleapis.com/css?family=Abel">
</head>

<div class="boeken">
    <h1>Wijzig hier de gebruiker</h1>
    <form action="editrij.php?id=<?php echo $id; ?>"  method="post" > <!-- you need to echo $id and close with ';' - changed: echo $id; -->
        <div class="row">
            <div class="col-25">
                <label for="gebruikers_naam"> vul hier de nieuwe gebruikers naam in: </label>
            </div></div>
        <br>
    <div class="row">
        <div class="col-75">
            <?php $gebruikers_naam = (isset($gebruikers_naam)) ? $gebruikers_naam : 'N/A'; ?> <!-- added a test to see if $gebruikers_naam is available -->
            <input type="text" name="voornaam" required="required" value="<?php echo $gebruikers_naam; ?>"/> <!-- variable is $gebruikers_naam, changed (echo and ';') -->
        </div>
    </div>
<br>
    <input type="submit" value="submit" name="submit" />
    </form>
</div>
</html>

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icomxhvb3#

您发送的不是变量gebruikers\u naam，而是voornaam。这行代码

<input type="text" name="voornaam" required="required" value="<?= $gebruikers_naam['gebruikers_naam'] ?>"/>

应该是

<input type="text" name="gebruikers_naam" required="required" value="<?= $gebruikers_naam['gebruikers_naam'] ?>"/>

另外，因为您在表单中使用变量$id和$gebruikers\u naam，所以应该在if子句之前为它们赋值。

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用php编辑/更新行不起作用/未定义变量

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