rails one to one association

I have an issue related to rails.
The class definition is given below.

    class Supplier < ActiveRecord::Base
      has_one :criteria

You need to specify the foreign key also (crt_sup_id) here as it is
non-standard.
On a side note I strongly recommend using the default id names unless
you absolutely cannot do that. It will make life much easier, as you
have already found.

Colin