php rollover link and show image form databse that has same id

php rollover link and show image form databse that has same id

I have a list of categories in a database that our echoed onto the page
like so:
echo '<li><a href=#?id='.$row['category_id'] .' "> ' .
$row['category_name'] . '</a></li>';
How would I echo that corresponding image(category_image) that is in the
database when I hover over these links individually?
Do I hide a div and then have it appear on hover with the image inside?
but then how do I transfer the id?
category_image is a path, not the actual image.