How to read images from MySQL database using PHP?

How to read images from MySQL database using PHP?

If the images are stored in a BLOB in the database, how to use the binary data that I get and turn it into an image using 开发者_Python百科src in <img> or using the CSS property background-image?

Thanks.

To directly use the binary data as a an image source, you can use the data URI scheme, for example:

$uri = 'data:image/png;base64,'.base64_encode($row['binary-data']);

This URI can then be used directly as the image’s source:

background-image: url(<?php echo $uri; ?>)
<img src="<?php echo $uri; ?>">

But that has some substantial disadvantages: Besides the lack of support for these data URIs in older browsers, data URIs do also have disadvantaged regarding payload, caching, and references.

What you should probably do, if storing images as BLOBs, is provide a URL that calls your script in a way that it can determine what image to return.

Use that URL as the src, or background-image: url(...) and in the script, read the BLOB from the database in to a variable.

Then output the variable after appropriate header information, telling the browser it is to receive an image, for instance:

header('Content-Type: image/jpeg');

Sending a Content-Length header and sensible information on caching/expiry would also be wise.

NB. Having said all that, I tend to be wary of using BLOBs in databases, they tend to cripple performance. When I want to store images, I store then in some directory structure and reference them in the database in some fashion.