[RESOLVED] session variables with image retrieval in mysql database

Bilbozilla

I am trying to pass an ID value from one page to withdraw data from an image database on another. I am trying to do this with session variables. If I hardcode the value for $id in the IEWIMAGE.PHP file, it works like a charm. I am trying to pass a session variable to the VIEWIMAGE.PHP file (shown below) from my td.php code snippet.

The output is fine (see printf stateement) but when it comes time to load the images from the viewimage.php reference, I get nothing.

I set a session variable $_SESSION['imageid'] within the "while" loop and unset it outside the loop.

td.php

while($row = mysqli_fetch_array($result,MYSQLI_BOTH))
{
	$imagequery = " SELECT id FROM upload where userid = '$row[8]'";
	$iqresult = mysqli_query($connection, $imagequery) or die('Error, QQuery failed');
	$resultrow = mysqli_fetch_array($iqresult, MYSQLI_BOTH);
$_SESSION['imageid'] = $resultrow['id'];
$shorty=$_SESSION['imageid'];

printf("<img src=\"./viewimage.php?id=%s\" class=\"w100 b1s000\" />", $shorty);
echo" </a>";

VIEWIMAGE.PHP


<?php
session_start(); 

include("./login_data.txt");
$id=$_SESSION['imageid'];

if($id) {
 $connection; //defined in login_data.txt
    @mysqli_select_db($connection, 'upload');
    $image=stripslashes($_REQUEST[id]);
    $query = "select content, type from upload where id=$id";
    $result = @mysqli_query($connection, $query) or exit("Error");
while ($row=mysqli_fetch_row($result)){
$content=$row[0];
$type=$row[1];
}
    Header( "Content-type: $type");
    echo $content;
mysqli_free_result($result);

};
?>

Bjom

there is no session_start() in the first snippet. If that is so and not just a copy/paste error, then this is why nothing gets stored in the session....

add

echo $id;

to the second snippet...

Bilbozilla

session_start() is at the top of the page in the first snippet. There's quite a bit of code, but the code shown is the limiting factor.

As for errors, I am not getting any images back. The html code as it appears on the page appears as

...
img src="./viewimage.php?pid=6" class="w100 b1s000" /> </a>	
...

But there is still no image in place.

Bjom

is that supposed to be up one folder from the current path? If so, try "../viewimage........"

also if I'm not mistaken, this looks like it should be the path and filename of an actual image, no? then the ?pid=6 part would not be helpful.

Bilbozilla

It is in the same directory.

The images are stored within the database as "mediumblob" datatypes.

the 6 provides an ID reference to pull the image.

Bjom

I understand that. Is the above html actually working as intended, i.e. is the script being called as intended?

try adding a var_dump($content); and see if anything is inside that variable.

Bilbozilla

I'm not sure how to initiate a var_dump command.

Bjom

var_dump($content);

put that line in front or instead of the header...; line

Bilbozilla

Thank you. I get a null value returned.

Bjom

that means your variable is empty 🙁

Just put in a var_dump for every variable right after it is supposed to get assigned a value, to find out where the script fails.

A few other things:

$image=stripslashes($_REQUEST[id]);
what does that line do?

@mysqli_select_db($connection, 'upload');
get rid of the @....it will suppress error messages. not something you want.

Also a minor mistake:
$REQUEST[id]);
should be:
$REQUEST['id']);

Bilbozilla

Fixed. I had my content and type switched on the view image page.

Thanks for your help.

Weedpacket

Bilbozilla wrote:
I set a session variable $SESSION['imageid'] within the "while" loop and unset it outside the loop.
$_SESSION['imageid'] = $resultrow['id'];
$shorty=$_SESSION['imageid'];

There's no point using a session variable there then. Within the while loop it only has one value that keeps changing, and then it's removed completely - and then there's nothing to be retained in the session and passed on to the next page.