I have a simple site layout. Everything is being pulled from a
database in such fashion that Page 1 of the site is referenced by
'pagename.php/?id=1', Page 2 is referenced by 'pagename.php/?id=2', and
so forth. In other words, I have only one page 'pagename.php' with a
couple of conditional statements and a navigation bar as a form using
method "get".

I need the middle content part on page 'pagename.php/?id=3' to pull
some information from a completely separate table. Is there a way to
accomplish that without resorting to

if ($_GET[id] = 3) {
// do a completely separate page layout with data pulled by the
needed page
}

I don't want to hardcode the condition because a user may delete row
where id=3.

Basically, is there a way to run a database query from inside a
database row while in phpMyAdmin?