MySQL + PHP: fetching data using foreign keys

Question

I have 2 tables (Users, Wall). The UserID in the Wall table is a foreign key. How would I go about fetching the users details using this? (I want to fetch the users Forename

Answer 1

select w.MessageID, w.Message, u.UserID, u.Forename, u.Surname
from Wall w
inner join Users u on w.UserID = u.UserID