PHP update which does not update form fields which are blank

Question

This is an extension of a question I asked a wee while ago which @eHussain was nice enough to help out with.

I have form which inserts various details into a MySQL table and uploads a file (the name of which is also registered in the database). This works fine. The issue comes when I update, say, the name and not the image. In this case the image name is over written as 'blank', and rightly so as that's the value in the file field.

The update code:

<?php
error_reporting(E_ALL^E_NOTICE);
define('INCLUDE_CHECK',true);
include "connect.php";

$target = "../uploads/";
$target = $target . basename( $_FILES['photo']['name']);

//This gets all the other information from the form
$name=$_POST['name'];
$url=$_POST['url'];
$description=$_POST['description'];
$pic=($_FILES['photo']['name']);
$author=$_POST['author'];
$company=$_POST['company'];
$published=$_POST['published'];
$dashboardID=$_POST['dashboardID'];

//Writes the information to the database
mysql_query("UPDATE dashboard SET name='$name', url='$url', description='$description', documentName='$pic', author='$author', company='$company', publish='$published' WHERE dashboardID='$dashboardID'");

//Writes the photo to the server

if(isset($_FILES['photo']['tmp_name'])) //  check if any file is uploaded
{
if(move_uploaded_file($_FILES['photo']['tmp_name'], $target))
{

header("Location: ../dashboard.php?success=2"); } else {

header("Location: ../dashboard.php?success=0"); }
}

?>

I understand the 'isset' to avoid a the error generated if no file is selected, but I don't understand how I can extent this to avoid updating a field which has a blank value.

Phil · Accepted Answer · 2011-02-03T03:55:07.953

1

Do a check on the $_FILES array before running the query.

From there, you can either dynamically build the query (including or excluding the documentName field) or alternatively, fetch the current value and assign it to $pic.

For example (untested)

$values = array(
    'name' => $name,
    'url'  => $url,
    // etc
);

if (isset($_FILES['photo']['name'])) {
    $values['documentName'] = $_FILES['photo']['name']
}

// mysql functions are naff, use PDO

$query = 'UPDATE dashboard SET %s WHERE dashboardID = :dashboardID';
$set = array();
foreach (array_keys($values) as $col) {
    $set[] = sprintf('`%s` = :%s', $col, $col);
}
$stmt = $pdo->prepare(sprintf($query, implode(', ', $set)));
$values['dashboardID'] = $dashboardID;

$stmt->execute($values);

edited Feb 03 '11 at 03:55

answered Feb 03 '11 at 03:42

Phil

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you are missing some quotes: $set[] = sprintf('`%s` = ":%s"', $col, $col); – dar7yl Jul 21 '11 at 18:49
@dar7yl No, that's not how SQL parameters work. You don't quote the parameter name – Phil Jul 22 '11 at 06:16

xkeshav · Answer 2 · 2011-02-03T06:00:41.163

0

@rrfive , please try below method, hope it will work,

//first put all post variable in an array 
$post_data = compact($_POST);    
$pic=($_FILES['photo']['name']);
//now push pic name in `$post_data`
if (!empty($pic) ) { array_push( $post_data,$pic ) }

//now use UPDATE query using `vsprintf` . but first check the order of `$post_data` @Thanks Phill

$stmt = "UPDATE dashboard SET 
                            name='%s', 
                            url='%s',
                            description='%s',                           
                            author='%s',
                            company='%s',
                            publish='%s'";
$stmt .=(!empty($pic)) ? documentName='%s', : "";
$stmt .= "WHERE dashboardID=%d";
// To check the complete query before execute. uncomment below 2 lines
//print vsprintf($stmt,$post_data);
//die;
mysql_query( vsprintf($stmt,$post_data) );

Reference
- compact
- vsprintf

edited Feb 03 '11 at 06:00

answered Feb 03 '11 at 05:42

xkeshav

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Plz sanitize post data using `mysql_real_escape_string` before `compact` – xkeshav Feb 03 '11 at 05:47
How do you guarantee the order of POST variables for use in `vsprintf()`? Also, if there is no upload, you will have more placeholders than values. – Phil Feb 03 '11 at 05:51
If you want help with your answer, you should post it as a separate question. – Phil Feb 03 '11 at 06:07
@Phil i m not asking help , i m just saying now this is fine or not, and if i paste it as separte question,people started commenting as duplicate Question – xkeshav Feb 03 '11 at 06:55

score -1 · Answer 3 · answered Feb 03 '11 at 03:43

-1

The following code should do the trick.

 if(isset($_FILES)){
      ...stuff...
 }

answered Feb 03 '11 at 03:43

Jose Vega

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PHP update which does not update form fields which are blank

3 Answers3