Update MySQL via Form showing a blank white page...

suttercain

Hello and happy "Zombie Jesus" day to everyone,

I am attempting my first update database, via a form, page. I have all the PHP code and HTML code and the connection to the database is working. But for some reason when I look at the page it's white. Not even the HTML is showing up.

Here is my entire code:

<html>
<head>
<title>ADMIN: Edit News</title>
<style type="text/css">
<!--
body,td,th {
	font-family: Arial, Helvetica, sans-serif;
}
.style3 {font-size: 12px}
-->
</style>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"></head>

<body>
<?php
	$story_id = $_POST['story_id'];
	require ('get_connected.php');

$query = "SELECT * FROM news WHERE story_id='story_id'";
$result = mysql_query($query);
$num = mysql_num_rows($result);

$i = 0;
while ($i<$num) {
$title = mysql_result($result, $i, 'title');
$body = mysql_result($result, $i, 'body');
$story_date = mysql_result($result, $i, 'story_date');
$author = mysql_result($result, $i, 'suthor');
$image = mysql_result($result, $i, 'image');
$image_text = mysql_result($result, $i, 'image_text');
$source = mysql_result($result, $i, 'source');
?>

	<form action="edit_news_complete.php" method="post">
<table width="840" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td><?php include ('header.html'); ?></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Use this form to submit news instantaneously to the Superman Database!</strong></td>
  </tr>
  <tr>
    <td><span class="style3">Please follow the directions that appear underneath the form input fields. An error can mess up the look of the news story when users are viewing it. </span></td>
  </tr>
  <tr>
    <td><input type="hidden" name="ud_story_id" value="<? echo $story_id; ?>"></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Title:</strong></td>
  </tr>
  <tr>
    <td><input name="ud_title" type="text" value="<?php echo $title; ?>" size="42" maxlength="40"></td>
  </tr>
  <tr>
    <td><span class="style3">The tiltle must be 40 Characters or less. Spaces counts as a character. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Story Body:</strong></td>
  </tr>
  <tr>
    <td><textarea name="ud_body" rows="15" cols="60" ><?php echo $body; ?></textarea></td>
  </tr>
  <tr>
    <td><span class="style3">Seperate paragraphs with a &lt;p&gt; tag. This will add a double spacing between paragraph. Please no other HTML code. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Story Date:</strong></td>
  </tr>
  <tr>
    <td><input type="text" name="ud_story_date" value="<?php echo $story_date; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">Please format the date like such: March 23rd, 2005 </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Author:</strong></td>
  </tr>
  <tr>
    <td><input type="text" name="ud_author" value="<?php echo $author; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">Credit the writer of the story for their work </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Image Name: </strong></td>
  </tr>
  <tr>
    <td><select name='ud_image'>
			<?php
$dir = "../images/news";
$dir = opendir($dir);
while (false !== ($image = readdir($dir))){
if (in_array($image, array(".", ".."))) continue;
?>
<option value='<?php echo $image; ?>'><?php echo $image; ?></option>
<?php
}
?>
		</select></td>
  </tr>
  <tr>
    <td><span class="style3">Select an available photo or <a href="picture_upload.php" target="_parent">upload one</a>. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Image Description: </strong></td>
  </tr>
  <tr>
    <td><input name="ud_image_text" type="text" value="<?php echo $image_text; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">This is the text that will appear below the image in the news story. Use this field to describe who or what is in the picture. Be as detailed as possible in one or two sentences. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Source:</strong></td>
  </tr>
  <tr>
    <td><p>
      <input type="text" name="ud_source" value="<?php echo $source ?>">
    </p></td>
  </tr>
  <tr>
    <td>
      <p class="style3">Please enter the source of this story. Starting at www. DO NOT enter http://. Example entry www.supermandatabase.com </p></td>
  </tr>
  <tr>
    <td></td>
  </tr>
</table>
<br><input type="submit" value="Update">
</form>
<?php
++$i;
}
	$ud_story_id = $_POST['ud_story_id'];
	$ud_title = $_POST['ud_title'];
	$ud_body = $_POST['ud_body'];
	$ud_story_date = $_POST['ud_story_date'];
	$ud_author = $_POST['ud_author'];
	$ud_image = $_POST['ud_image'];
	$ud_source = $_POST['ud_source'];
	$ud_image_text = $_POST['ud_image_text'];

require ('get_connected.php');

$query = "UPDATE news SET title = '$ud_title', body = '$ud_body', story_date = '$ud_story_date', author = '$ud_author', image = '$ud_image', source = '$ud_source', image_text = '$ud_image_text' WHERE story_id = '$ud_story_id'";

?>
</body>
</html>

I understand there may be errors, since this is my first shot at it, but I don't understand why I am getting a blank page... shouldn't I at least be seeing the from?

Thanks in advance.

suttercain

Okay I just ran <?php error_reporting(E_ALL); ?> and got this:

Notice: Undefined index: story_id in D:\wamp\www\Superman\edit_news.php on line 17

Notice: Undefined index: ud_story_id in D:\wamp\www\Superman\edit_news.php on line 159

Notice: Undefined index: ud_title in D:\wamp\www\Superman\edit_news.php on line 160

Notice: Undefined index: ud_body in D:\wamp\www\Superman\edit_news.php on line 161

Notice: Undefined index: ud_story_date in D:\wamp\www\Superman\edit_news.php on line 162

Notice: Undefined index: ud_author in D:\wamp\www\Superman\edit_news.php on line 163

Notice: Undefined index: ud_image in D:\wamp\www\Superman\edit_news.php on line 164

Notice: Undefined index: ud_source in D:\wamp\www\Superman\edit_news.php on line 165

Notice: Undefined index: ud_image_text in D:\wamp\www\Superman\edit_news.php on line 166

I don't know why though? I thought I did define them...

scross

This is quite a common error:

$ud_story_id = $_POST['ud_story_id'];
$ud_title = $_POST['ud_title'];
$ud_body = $_POST['ud_body'];
$ud_story_date = $_POST['ud_story_date'];
$ud_author = $_POST['ud_author'];
$ud_image = $_POST['ud_image'];
$ud_source = $_POST['ud_source'];
$ud_image_text = $_POST['ud_image_text'];

At a first look the code seems perfectly fine however in each of these lines of code you referencing a value within $POST which does not neccessarily exist. So, if the user has not submitted a value through $POST then PHP returns an error because you reference a value which doesn't exist. The solution is to check that each $_POST variable exists before you assign it as a value, using the function isset(). Here's some example code:

if(isset($_POST['ud_story_id'])){ $ud_story_id = $_POST['ud_story_id']; }else{ $ud_story_id = ''; }

However, this can be greatly simplified by using a ternary operator ( http://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary ):

$ud_story_id = isset($_POST['ud_story_id']) ? $_POST['ud_story_id'] : '';

This way you can avoid all the nasty errors from php.

dagon

or loop through post with

foreach ($_POST as $key => $value) {
    $$key = addslashes(trim($value));
  }

Don't trust post add security

suttercain

Hi guys,

thanks for the advice.

I made the change suggested above and ran this code

<?php
	if(isset($_POST) && !empty($_POST)){ $story_id = $_POST['story_id']; }
	require ('get_connected.php');

$query = "SELECT * FROM news WHERE story_id='story_id'";
$result = mysql_query($query);
$num = mysql_num_rows($result);

$i = 0;
while ($i<$num) {
$title = mysql_result($result, $i, 'title');
$body = mysql_result($result, $i, 'body');
$story_date = mysql_result($result, $i, 'story_date');
$author = mysql_result($result, $i, 'suthor');
$image = mysql_result($result, $i, 'image');
$image_text = mysql_result($result, $i, 'image_text');
$source = mysql_result($result, $i, 'source');
?>

	<form action="edit_news_complete.php" method="post">
<table width="840" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td><?php include ('header.html'); ?></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Use this form to submit news instantaneously to the Superman Database!</strong></td>
  </tr>
  <tr>
    <td><span class="style3">Please follow the directions that appear underneath the form input fields. An error can mess up the look of the news story when users are viewing it. </span></td>
  </tr>
  <tr>
    <td><input type="hidden" name="ud_story_id" value="<? echo $story_id; ?>"></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Title:</strong></td>
  </tr>
  <tr>
    <td><input name="ud_title" type="text" value="<?php echo $title; ?>" size="42" maxlength="40"></td>
  </tr>
  <tr>
    <td><span class="style3">The tiltle must be 40 Characters or less. Spaces counts as a character. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Story Body:</strong></td>
  </tr>
  <tr>
    <td><textarea name="ud_body" rows="15" cols="60" ><?php echo $body; ?></textarea></td>
  </tr>
  <tr>
    <td><span class="style3">Seperate paragraphs with a &lt;p&gt; tag. This will add a double spacing between paragraph. Please no other HTML code. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Story Date:</strong></td>
  </tr>
  <tr>
    <td><input type="text" name="ud_story_date" value="<?php echo $story_date; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">Please format the date like such: March 23rd, 2005 </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Author:</strong></td>
  </tr>
  <tr>
    <td><input type="text" name="ud_author" value="<?php echo $author; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">Credit the writer of the story for their work </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Image Name: </strong></td>
  </tr>
  <tr>
    <td><select name='ud_image'>
			<?php
$dir = "../images/news";
$dir = opendir($dir);
while (false !== ($image = readdir($dir))){
if (in_array($image, array(".", ".."))) continue;
?>
<option value='<?php echo $image; ?>'><?php echo $image; ?></option>
<?php
}
?>
		</select></td>
  </tr>
  <tr>
    <td><span class="style3">Select an available photo or <a href="picture_upload.php" target="_parent">upload one</a>. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Image Description: </strong></td>
  </tr>
  <tr>
    <td><input name="ud_image_text" type="text" value="<?php echo $image_text; ?>"></td>
  </tr>
  <tr>
    <td><span class="style3">This is the text that will appear below the image in the news story. Use this field to describe who or what is in the picture. Be as detailed as possible in one or two sentences. </span></td>
  </tr>
  <tr>
    <td>&nbsp;</td>
  </tr>
  <tr>
    <td><strong>Source:</strong></td>
  </tr>
  <tr>
    <td><p>
      <input type="text" name="ud_source" value="<?php echo $$source ?>">
    </p></td>
  </tr>
  <tr>
    <td>
      <p class="style3">Please enter the source of this story. Starting at www. DO NOT enter http://. Example entry www.supermandatabase.com </p></td>
  </tr>
  <tr>
    <td></td>
  </tr>
</table>
<br><input type="submit" value="Update">
</form>
<?php
++$i;
}
if (isset($_POST)) {
	$ud_story_id = isset($_POST['ud_story_id']) ? $_POST['ud_story_id'] : ''; 
	$ud_title = isset($_POST['ud_title']) ? $_POST['ud_title'] : ''; 
	$ud_body = isset($_POST['ud_body']) ? $_POST['ud_body'] : ''; 
	$ud_story_date = isset($_POST['ud_story_date']) ? $_POST['ud_story_date'] : ''; 
	$ud_author = isset($_POST['ud_author']) ? $_POST['ud_author'] : ''; 
	$ud_image = isset($_POST['ud_image']) ? $_POST['ud_image'] : ''; 
	$ud_source = isset($_POST['ud_source']) ? $_POST['ud_source'] : ''; 
	$ud_image_text = isset($_POST['ud_image_text']) ? $_POST['ud_image_text'] : ''; 

require ('get_connected.php');

$query = "UPDATE news SET title = '$ud_title', body = '$ud_body', story_date = '$ud_story_date', author = '$ud_author', image = '$ud_image', source = '$ud_source', image_text = '$ud_image_text' WHERE story_id = '$ud_story_id'";
mysql_query($query) OR die(mysql_error());
}
?>
</body>
</html>

I get two diffrent results based on changing this the WHERE

If I run this:

	$query = "SELECT * FROM news WHERE story_id='story_id'";
	$result = mysql_query($query);
	$num = mysql_num_rows($result);

I get the blank white page.

If I run this:

	$query = "SELECT * FROM news WHERE story_id='$story_id'";
	$result = mysql_query($query);
	$num = mysql_num_rows($result);

I get this error:

Notice: Undefined variable: story_id in D:\wamp\www\Superman\edit_news.php on line 20

Any additional suggestions? Thanks again guys.

bradgrafelman

There is no 'story_id' element in your form.

suttercain

Got it.

Weedpacket

Why use a loop....

$_POST = array_map('addslashes', array_map('trim', $_POST));

suttercain

I knew it was too good to be true. So I am still getting the error... but I got the form to display and populate.

Error:
Notice: Undefined index: story_id in D:\wamp\www\Superman\edit_news.php on line 17

I split the code into two pages.
edit_news.php and edit_news_submitted.php

I tried to submit the changes to the form even with the error being displayed and it did not update the record as I knew it wouldn't.

Here is the code edit_news.php: I omitted the html table code for easier reading

<?php error_reporting(E_ALL); ?>
<html>
<head>
<title>ADMIN: Edit News</title>
<style type="text/css">
<!--
body,td,th {
	font-family: Arial, Helvetica, sans-serif;
}
.style3 {font-size: 12px}
-->
</style>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"></head>

<body>
<?php
	if(isset($_POST) && !empty($_POST)){ $story_id = $_POST['story_id']; }
	require ('get_connected.php');

$query = "SELECT * FROM news WHERE story_id='2'";
$result = mysql_query($query);
$num = mysql_num_rows($result);

$i = 0;
while ($i<$num) {
$title = mysql_result($result, $i, 'title');
$body = mysql_result($result, $i, 'body');
$story_date = mysql_result($result, $i, 'story_date');
$author = mysql_result($result, $i, 'author');
$image = mysql_result($result, $i, 'image');
$image_text = mysql_result($result, $i, 'image_text');
$source = mysql_result($result, $i, 'source');
?>

<form action="edit_news_submitted.php" method="post">
<?php include ('header.html'); ?>
<input type="hidden" name="ud_story_id" value="<?php echo $story_id; ?>">
<input name="ud_title" type="text" value="<?php echo $title; ?>
<textarea name="ud_body" rows="15" cols="60" ><?php echo $body; ?>
<input type="text" name="ud_story_date" value="<?php echo $story_date; ?>">
<input type="text" name="ud_author" value="<?php echo $author; ?>">
<input name="ud_image" type="text" value="<?php echo $image; ?>">
<input name="ud_image_text" type="text" value="<?php echo $image_text; ?>">
<input type="text" name="ud_source" value="<?php echo $source ?>">

<br><input type="submit" value="Update"><br>
No Preview is given when "Updating" a News Story. You should verifiy the changes are correct.
</form>
<?php
++$i;
}

?>
</body>
</html>

Here is the code for edit news submitted:

<?php error_reporting(E_ALL); ?>
<html>
<head>
<title>ADMIN: Edit News</title>

<?php


if (isset($_POST)) {
	$ud_story_id = isset($_POST['ud_story_id']) ? $_POST['ud_story_id'] : ''; 
	$ud_title = isset($_POST['ud_title']) ? $_POST['ud_title'] : ''; 
	$ud_body = isset($_POST['ud_body']) ? $_POST['ud_body'] : ''; 
	$ud_story_date = isset($_POST['ud_story_date']) ? $_POST['ud_story_date'] : ''; 
	$ud_author = isset($_POST['ud_author']) ? $_POST['ud_author'] : ''; 
	$ud_image = isset($_POST['ud_image']) ? $_POST['ud_image'] : ''; 
	$ud_source = isset($_POST['ud_source']) ? $_POST['ud_source'] : ''; 
	$ud_image_text = isset($_POST['ud_image_text']) ? $_POST['ud_image_text'] : ''; 

require ('get_connected.php');

$query = "UPDATE news SET title = '$ud_title', body = '$ud_body', story_date = '$ud_story_date', author = '$ud_author', image = '$ud_image', source = '$ud_source', image_text = '$ud_image_text' WHERE story_id = '$ud_story_id'";
mysql_query($query) OR die(mysql_error());

echo "Thank you";
}
?>
</body>
</html>

I have been scratching my head for hours on this one. Can anyone suggest a remedy? Thanks.[/code]

suttercain

If I change

if(isset($_POST) && !empty($_POST)){ $story_id = $_POST['story_id']; }

if(isset($_POST) && !empty($_POST)){ $story_id = $_POST['ud_story_id']; }

The error goes away, but when I submit the changes no update to the database occurs.

Thanks again for any help you can provide.

scross

1) Firstly, change:

if(isset($_POST) && !empty($_POST)){ $story_id = $_POST['story_id']; }

to:

if(isset($_POST['story_id']) && !empty($_POST['story_id'])){ $story_id = $_POST['story_id']; }else{ die('Story ID could not be found'); }

I added an ELSE condition on the end to display an error if the story ID either doesn't exist or it is an empty value. Once you have completed the code it would be wise to place your own perfectly formatted error instead of the die() function call. But for now, it will suffice. I also sorted out the fact that you were checking the existence of $_POST(which I believe always exists unless you unset it) instead of the actual value you wanted.

2) You could change:

while ($i<$num) {

to something like:

while($story = mysql_fetch_assoc($result)){

Then for each of your values just use:

$title = $story['title'];

instead of your mysql_result() function calls which are a great deal slower than mysql_fetch_assoc().

3) In your second file remove:

if (isset($_POST)) {

It is entirely useless and is always true.

4) After:

$ud_story_id = isset($_POST['ud_story_id']) ? $_POST['ud_story_id'] : '';

you should probably add a check to make sure $ud_story_id is not empty:

if(empty($ud_story_id)){ die('It was empty'); }

And, again, you'll need to replace that with a proper error in the future, this is ust for debugging.

Please tell me the output now...