Magento

Is there any way to do a clean install on a server, with a new database, then reference another database post-install?

I have an old database I downloaded a dump from mysql admin, then upgraded my installation only to find it screwed up. So I had to re-install a new version on the server, but I would like to bring in my old products. How would I go about doing this?

I tried to import tables via php admin, but there are constraints blocking me. Surely there is a setting somewhere in a config file I can change somewhere?