Joining tables in two dbs

[eluser]Eric Brown[/eluser]
I have two databases, one for reporting and one for their account data. PConnect = FALSE

In my query, since I have to connect two both databases and then join on user_id, what's the right format for generating a query? I know I can hardcode the database.tablename in the SQL query, but should I need to move hosts, and the database names change this will make my code a nightmare to update.

Can I insert the db object names in the SQL itself?