Thanks! However, I'm still a little confused. On this page: (https://panel.dreamhost.com/kbase/index.cgi?area=2682) it says :
3. After that you simply go to Goodies::MySQL on the panel. If you already created a database and a mysql host under your domain, click on ¨Add host¨ and add a host mysql.foobar.dreamhosters.com to you database. If you haven´t done this yet, create your database and the host at once. After the usual setup time, it´s possible to access phpMyAdmin through http://mysql.foobar.dreamhosters.net and do whatever you need to do with it.
I can't seem to find this mysterious 'Add host' button. I have already set up a DB on a the domain w/o DNS, but I can't figure out how to add a second hostname to this DB using the 'add host' button as mentioned above so I can fully test the web site before transfering the DNS. Am I just blind?