How to display blob with PHP? - php

Question

Why can't my php display the image?
<?php
include("sql.php");
//$sql = "SELECT * FROM filesdb WHERE fileid = 5";
$id = $_GET['id'];
// do some validation here to ensure id is safe
$sql = "SELECT * FROM filesdb WHERE fileid =$id";
echo $sql."<br>";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
//header('content-type: image/jpeg');
echo "<br>Fileid:".$row['fileid'];
echo "<br>FileName:".$row['filename'];
header("Content-Type: image/jpeg");
echo "<br>".$row['dbforfile'];
}
it can display fileid and filename, but not dbfofile, which is a BLOB.

Answer 1

If you're downloading the file contents, you must not put HTML elements around it.
You can also only send one image at a time, so there's no point in looping.
<?php
include("sql.php");
//$sql = "SELECT * FROM filesdb WHERE fileid = 5";
$id = $_GET['id'];
// do some validation here to ensure id is safe
$sql = "SELECT dbforfile FROM filesdb WHERE fileid =$id";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
header('content-type: image/jpeg');
$row = $result->fetch_assoc();
echo $row['dbforfile'];
}

Answer 2

You are only doing one image, so you don't need a loop. But if you want to do multiples; you need to use an img tag and call another PHP script as if it were an image in the src and have that script output the image (with headers). Or you can use base64 encoded data as the image source in the tag:
while($row = $result->fetch_assoc()) {
echo "<br>Fileid:".$row['fileid'];
echo "<br>FileName:".$row['filename'];
echo "<br>";
echo '<img src="data:image/jpeg;base64,'.base64_encode($row['dbforfile']).'"/>';
}