Do you absolutely need foreign keys in a database?

Question

I was wondering how useful foreign keys really are in a database. Essentially, if the developers know what keys the different tables depend on, they can write the queries just

Answer 1

Foreign Keys make life so much easier when using report builders and data analysis tools. Just select one table, check the include related tables box and BAM! you've got you're report built. Ok Ok, it's not that easy, but they certianly save time in that respect.