PDO to retrieve and display images without creating files - php

Question

Trying to loop through a test database with images (I know many say not to do this, but it simplifies so much in terms of backups, etc.). I can get the result I want by creating image files on the fly, but there must be a way to do this without creating files. Can someone suggest a syntax I can use without having to create these image files?
Here is what I have working:
<?php
// configuration
$dbhost = "localhost";
$dbname = "test";
$dbuser = "root";
$dbpass = "";
// database connection
$conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);
// query
$sql = "SELECT id,title,author,description,cover FROM books";
$q = $conn->prepare($sql);
$q->execute();
$q->bindColumn(1, $id);
$q->bindColumn(2, $title);
$q->bindColumn(3, $author);
$q->bindcolumn(4, $description);
$q->bindColumn(5, $cover, PDO::PARAM_LOB);
while($q->fetch())
{
file_put_contents($id.".png",$cover);
echo ("<img src='".$id.".png'><br />, $title, $author, $description,<br/>");
}
?>
I am thinking that we should be able to eliminate the "file_put_contents.." line and in the echo line, replace the
<img src='".$id.".png'>"
with some php/pdo statement that retrieves the blob and puts it in the proper format. Tried a few things, but have not been successful.
Any suggestions would be helpful!

Answer 1

you do not need to do it in 2 separate files and invoke the script in src attribute of img tag.
Try do this
echo '<img src="data:image/'.$type.';base64,'.base64_encode($image).'"/>';
Where $type is the extension of the image(.png/.jpeg/....) and $image is the binary of the image that you have stored in your DB. in my case I pull the value of the type of image from the db, if you store always the same extension(ex jpeg) you can simply write:
echo '<img src="data:image/jpeg;base64,'.base64_encode($image).'"/>';
the method is an alternative to do that with 2 files.

Answer 2

You need to write code in 2 files. As when browser gets <img src="path/to img_file"> code (or code like <script src="....">), etc, a separate request is sent to server by browser at src path value. So, you also need to create file img_file.
Pseudo code is below,
Firstfile.php
<?php
..................... Other code
while($q->fetch())
{
?>
<img src="image.php?id=<?php echo $id; ?>"><br />,
<?php
echo "$title, $author, $description<br/>";
}
?>
And at image.php file,
header('Content-Type: image/png');
$id = $_GET['id'];
$query = " ..... where id = '".$_GET['id']."'";
//You need error handling if $_GET['id'] is integer and valid value. I am not writing this error handling code
if($q->row_count!=1){
//no database row found. It's error.
echo "Show no image found image. As browser expects image you can not write text here";
die;
}
//it's valid image, else code is already terminated by above die.
while($q->fetch())
{
//show image
echo $cover;
}
?>
I wrote Pseudo code exact code depend on requirements.
If you want .png extension, you can use Apache rewrite. Google it you will get it.
When first time i wrote answer, I missed last php ending tag. By the way, last ending tag ?> is optional in php.
If you are getting X , it seems first file code is ok. As imag_file is not at server, it's showing 404 error. View source to check whether $_GET['id'] is correct. If id is correct, then you want to write at file img_file.php