Is it possible to search two tables (main table plus it's user table) at the same time?

I want to be able to search the two tables using search_form.html, modify_search_form.html and delete_search_form.html (e.g be able to search using fields such as Username, Name, Email, etc that are stored in the user table and/or other fields from the main table.) I have added a lot of additional fields to the user table that I need to search on from within the main tables html forms.

As the tables are related, is it possible to do a join or somthing and search them together?

What code would I need to change?

Thanks.

Simon.