WampServer

I use WAMP 5 and have a trouble with subqueries on more than one table.
I can't combine two tables if I set my primary keys to unique numbers, but I can combine two tables but not a third one if I don't set the primary keys to unique numbers.
What's wrong here?
Can someone help me out quickly on this one please?

I did a search and found that a simple form written in PHP will do better than phpmyadmin.

I suppose that means that I have to set the keys to unique numbers then?

Am currently working with a php form, but have some trouble with the connection to the database.
The form works perfect when run on another server but not when I try to run it locally. It just doesn't collect any data from the database., everything else is fine.

search this forum for short ASP style tags.