I have three models:
class User < ActiveRecord::Base has_many :basiccases end class Basiccase < ActiveRecord::Base belongs_to :user belongs_to :form3_c end class Form3C < ActiveRecord::Base has_one :basiccases end How can I add a new Form3C to the Basiccase? Do I need to use a Basiccase controller or Form3C controller to create a form? If I use Form3cController how can I set the foreign key in the BasiccaseController?
Relationships like has_one are defined on models rather than controllers. I think you want this (to be able to add a Form3c to a Basiccase--not sure which direction you want the relationship to go):
class Form3c < ActiveRecord::Base belongs_to :basiccase end class Basiccase < ActiveRecord::Base belongs_to :user has_one :form3c end For tips on building the controller and form (view), look at this Rails tutorial, starting around section 6.
Though your naming of model is not that convincing, I am assuming your basiccases table has one column form3c_id.
You need to create a form for form3c object then in controller you can build a basiccase object like @form3c_build_basiccase which will automatically take form3c_id as a foreign key. Refer to this rails cast.
Or you may go for form3c model accepts_nested_attributes_for :basiccase. See about it here.
has_onerelation should go into a model, not a controller. So if you have aForm3Cmodel class, try to add there the relation. Thehas_onerelation should go to singular as inhas_one :basiccase. You would normally build theBasiccasefrom theForm3Cinstance:self.build_basiccasewill build the basiccase thatbelongs_toForm3C.