Img download from database

clamicun

Subject: Download and show images from a database.

Here is the file to download images from a database (works fine if id is set).

//get_img.php
<?php
//$id = 3;
$basename = "xxx";
$password = "xxx";
$tablename = "xxx";
$db_connect = mysql_connect ('localhost','root',$password);
$db_select = mysql_select_db ($basename,$db_connect);
$strQuery = "SELECT * FROM $tablename WHERE id = $id ";
$result=mysql_query($strQuery);
$row=mysql_fetch_assoc($result);
header("Content-type: {$row['image_type']}");
// Das ist das Bild
echo $row['bin_data'];
?>

And now every "expert" explains the following ...

You have to include this code into your webpage.
<img src="get_img.php?id=3">

o.k. Here is the ""webpage""

Does not work - of course. Here is my question ...

How can a simple 'img tag' - somewhere in a site communicate (without a formular) with that particular phpfile and send parameters?
I obviously don´t understand some important basics.
Someone could explain this with a few words ?
Mic from Arraial D´Ajuda/Bahia/Brassil
clamicun@bol.com.br

Weedpacket

When posting code, please use the formatting tags described in this FAQ to make it easier to read, thank you.

You probably want to use $GET['id']. For safety's sake, write it as

$id=(int)$_GET['id'];

and deal with the possibility that there might not be a record with the given ID in the database.

clamicun

For whatever´s sake,
why didn´t you answer my very explicit question or did you not read the text ?

The question was on img tags. And do not think you are dealing with a complete idiot. Of course the image with that particular ID is in the DB.

Weedpacket

Sorry, maybe I didn't use enough words (and I've figured out that by "formular" [sic] you mean querystring).

First, a question or two of my own:

calmicun wrote:
Does not work - of course.

Why "of course"? It looks like a perfectly legitimate URL to me. And what does it do instead of working?

If you want to serve the image with URLs that don't have querystrings, then the most robust method would probably be to - once you've decided how the URLs should be written: since URLs for distinct IDs need to be themselves distinct, the ID would probably appear in it somewhere - configure the server to rewrite the URL into the above "get_img.php?id=3" form (in Apache for example this would be via the mod_rewrite module). After that, adding the line of code I gave in my previous post would retrieve that value and store it in the local $id variable.

clamicun wrote:
Of course the image with that particular ID is in the DB.

And of course you'll never get a request for a bad ID.

johanafm

Weedpacket;10935461 wrote:
Sorry, maybe I didn't use enough words (and I've figured out that by "formular" [sic] you mean querystring).

Since he wrote "without a formular", my interpretation is that he means "wihtout a form", and thus it would be possible to use a querystring. But we are playing guessing games...

So, if my guess is correct, then just tack on a query string with the id at the end of the url

?id=1234&amp;anything_else=you_need

And that matches exactly what you yourself had in your original post, meaning that Weedpacket really did answer your very specific question. Along with the above, you would use

$id = (int) $_GET['id']

And you also got some additional information about your script not receiving a valid id. Here's some more info along the same lines

// make sure you have an id at all. wrap your entire image script in this
if (isset($_GET['id'])) {

}

And to get good answers, you need to ask good questions unless dealing with psychics. "which obviously doesn't work" is not very helpful (especially not when there is nothing wrong with that particular part). "Gives me the following error: ..." is a lot better. Or even "once I have this, what else is needed?".

clamicun wrote:
For whatever´s sake,
why didn´t you answer my very explicit question or did you not read the text ?

Really? Why bash the people trying to help you? Moreover, you actually really did get the help you asked for. So what's the problem?

clamicun

ok.
Thanks a lot. Everything is resolved. I am am an idiot who does not speak english properly and in the future will "travel" exclusively to 'portugues' pages.
Mic from Brazil