search for: is_supervisor

I''m struggling with a single table type (self) lookup. my ''personnel'' model has a supervisor_id and is_supervisor column. The supervisor''s select list is created by @supv = Personnel.find(:all, :conditions => ["is_supervisor = true"], :order => ''last_name'') in my personnel model, I have the following... def supervisor if Personnel.find_by_id(self.supe...

Let''s imagine we are modelling a company that have several shops. I have a Worker model and a Shop model. A worker belongs_to a shop, and each shop has_many workers. But, in a shop there''s a distinguished worker that is the supervisor create table shops ( ... worker_id integer -- the supervisor ); How would you express this relationship?