How To Put The Echo Command Inside A While String

I'm trying to make a fun side project and have come to a stop on a small problem. I am trying to have the echo command placed inside of the while and mysqli_fetch_assoc command as the data changes everytime the page refreshes from the select from table random function.

The line of code looks like this:

<?php while($toolboxaddon = mysqli_fetch_assoc($toolboxaddon_set)) { ?>

However I need the words after $ to be changed so was looking for something like this to work

<?php while($ echo h($item['item']);addon = mysqli_fetch_assoc($ echo h($item['type']);addon_set)) { ?>

This is probably explained poorly, I would appreciate if anyone could lend some time to help me where I can show in more details what exactly I am trying to accomplish.