Hi, another probably easy to answer question for those of you who know what they are doing :). Situation is the same as describted in http://thread.gmane.org/gmane.comp.lang.ruby.rails/22154 Now that I finally have the belongs_to at the right place other problems occour. 1. Do I have to put a belongs_to, has_many ... on each side of the connection? Or is a X belongs_to Y enough and the Y has_many X unnessesary? 2. What about pluralization? I use the model-name as attribute, right? In singular or plural? 3. How do I easily test if the new functions that the belong_to created are up and running? 4. Finnaly the error I get when trying to create a new DB-Entry. What am I doing wrong? #23000Cannot add or update a child row: a foreign key constraint fails: INSERT INTO tents (`name`, `date_update_at`, `desc`, `tent_type_id`, `creator_dealer_id`) VALUES(''Alabama'', ''2005-09-19 16:48:00'', ''asdf'', 0, 0) Thanks a lot! ~Tobias -- Weblog: http://flyingsparks.wwwfiles.de/