表单不更新数据库

Question

I have a form with profile details, it retrieves data from my database but doesn't update it. Is there something wrong that I am not seeing? I have tried using echo's to check if my code gets to certain places, but it doesn't work yet.

<?php
session_start();

$dbhost = "localhost";
$dbuser = "pc4u0fi_username";
$dbpass = "pc4upc4u1";
$dbname = "pc4u0fi_pc4u";

// Create connection
$conn = new mysqli($dbhost, $dbuser, $dbpass, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}

$showalertsuccess = false;
$showalertdanger = false;

$retrieve = "SELECT * FROM Klanten WHERE ID = '".$_SESSION['ID']."'";
$result = mysqli_query($conn, $retrieve);
$data = mysqli_fetch_assoc($result);

$minion = $_GET['ID'];

if(isset($_POST['submit']))
{
$voornaam = $_POST['voornaam'];
$achternaam = $_POST['achternaam'];
$email = $_POST['email'];
$username = $_POST['username'];
$password = $_POST['wachtwoord'];
$woonplaats = $_POST['woonplaats'];
$postcode = $_POST['postcode'];
$straat = $_POST['straat'];
$huisnr = $_POST['huisnr'];
$telnr = $_POST['telnr'];

$query = "UPDATE Klanten SET klant_voornaam='$voornaam', klant_achternaam='$achternaam', klant_email='$email', klant_username='$username', klant_wachtwoord='$password', klant_woonplaats='$woonplaats', klant_postcode='$postcode', klant_straat='$straat', klant_huisnr='$huisnr', klant_telefoonnnummer='$telnr' WHERE ID = '".$_SESSION['ID']."'";

if ($conn->query($query) === TRUE)
{
    $showalertsuccess = true;
}
else
{
    $showalertdanger = true;
}
}
?>
<h1 style="margin-left: 10px;">Uw gegevens</h1><br>
<form class="form-horizontal" role="form" method="post">
<div class="alert alert-success fade in" <?php if($showalertsuccess === false) { ?> style="display:none" <?php } ?>>
    <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
    <strong>Gelukt!</strong> Uw account is gewijzigd.
</div>
<div class="alert alert-danger fade in" <?php if($showalertdanger === false) { ?> style="display:none" <?php } ?>>
    <a href="#" class="close" data-dismiss="alert" aria-label="close">&times;</a>
    <strong>Let op!</strong> Er is een fout opgetreden.
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="vnaam">voornaam:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="voornaam" value="<?=$data['klant_voornaam'];?>" name="voornaam" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" for="achternaam" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;">Achternaam:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="achternaam" value="<?=$data['klant_achternaam'];?>" name="achternaam" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="email">Email:</label>
    <div class="col-sm-10">
        <input type="email" class="form-control" id="email" value="<?=$data['klant_email'];?>" name="email" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="username">Username:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="username" value="<?=$data['klant_username'];?>" name="username" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="wachtwoord">Wachtwoord:</label>
    <div class="col-sm-10">
        <input type="password" class="form-control" id="wachtwoord" value="<?=$data['klant_wachtwoord'];?>" name="wachtwoord" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="woonplaats">Woonplaats:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="woonplaats" value="<?=$data['klant_woonplaats'];?>" name="woonplaats" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" for="postcode" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;">Postcode:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="postcode" value="<?=$data['klant_postcode'];?>" name="postcode" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="straat">Straat:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="straat" value="<?=$data['klant_straat'];?>" name="straat" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="huisnr">Huisnummer:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="huisnr" value="<?=$data['klant_huisnr'];?>" name="huisnr" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <label class="control-label col-sm-2" style="text-align: left; width: 120px; margin-left: 20px; margin-top: 10px;" for="telnr">Telefoonnummer:</label>
    <div class="col-sm-10">
        <input type="text" class="form-control" id="telnr" value="<?=$data['klant_telefoonnummer'];?>" name="telnr" style="width: 250px; margin-top: 10px; margin-left: 40px;" required placeholder="">
    </div>
</div>
<div class="form-group">
    <div class="col-sm-offset-2 col-sm-10">
        <button type="submit" style="margin-left: 170px; margin-bottom: 20px;" class="btn btn-default" name="submit">Wijzigen</button>
    </div>
</div>
</form>

Answer 1

Just put the SELECT query below UPDATE part, so that you will get the last updated data

//UPDATE PART
if(isset($_POST['submit']))
{
  $voornaam = $_POST['voornaam'];
  $achternaam = $_POST['achternaam'];
  $email = $_POST['email'];
  $username = $_POST['username'];
  $password = $_POST['wachtwoord'];
  $woonplaats = $_POST['woonplaats'];
  $postcode = $_POST['postcode'];
  $straat = $_POST['straat'];
  $huisnr = $_POST['huisnr'];
  $telnr = $_POST['telnr'];

  $query = "UPDATE Klanten SET klant_voornaam='$voornaam',  lant_achternaam='$achternaam', klant_email='$email', klant_username='$username', klant_wachtwoord='$password', klant_woonplaats='$woonplaats', klant_postcode='$postcode', klant_straat='$straat', klant_huisnr='$huisnr', klant_telefoonnnummer='$telnr' WHERE ID = '".$_SESSION['ID']."'";

  if ($conn->query($query) === TRUE)
  {
    $showalertsuccess = true;
  }
  else
  {
    $showalertdanger = true;
  }
}


// SELECT QUERY
$retrieve = "SELECT * FROM Klanten WHERE ID = '".$_SESSION['ID']."'";
$result = mysqli_query($conn, $retrieve);
$data = mysqli_fetch_assoc($result);

Answer 2

如果您使用此if (isset($_POST['submit'])) { ... }您的表单中必须具有<input type="hidden" name="submit" value="ok">