Understanding Image Display Issues with MySQL BLOB

When attempting to display an image stored as a BLOB in a MySQL database, developers often encounter an issue where any text echoed before or after the image's header causes the image to display incorrectly.

Cause of the Issue

The problem arises because the web browser interprets any text echoed outside the image data stream as part of the image. This is due to the fact that the header and image data must be delivered continuously and without interruption.

Solution

To display other items and the image together without interruption, you can convert the image data into base64 and embed it within an tag. This approach allows you to include text and other elements in the HTML output while still displaying the image.

Here's a revised version of the code:

echo '';
echo 'Hello world.';

Note: While this solution allows you to display both the image and other text, it's not ideal because it cannot be cached and can be slow on mobile devices. Consider checking the caniuse documentation for more information on data URIs.