Execute PHP Code

In one of columns in my table database i want to have a php function call
ex:

<?php echo display_photo_if_exist('1','John Cena'); ?>

Where can i find the function in which i want the function to execute, because at the moment this text is commented out and after load table look this:

<td class="  conqueror_photo wpda_format_string">
"<!--?php echo display_photo_if_exist('1','John Cena'); ?-->"
</td>