Problem with the association

Rails
1

I have a problem with the association.

I have the model called Invoice whit the associations:
belongs_to :company
belongs_to :client
belongs_to :type_invoice
has_many :row_invoices
belongs_to :bank
belongs_to :payment

When i create the invoice i use a session variable, so i can add all the
information i wont and I can save all at the end. This is all ok.

def new
session[:invoice] = Invoice.new # new invoice
session[:invoice].company = Company.find(1) # load company
… # other association
end

Then in my view with the command <%= debug(session[:invoice]) %> i can
see
company: !ruby/object:Company
attributes:
name
…

Then when I wont edit the Invoice I load it in the same session variable
(session[:invoice] = Invoice.find(params[:id])) i do:

def edit
session[:invoice] = Invoice.find(params[:id]) # load attributes
session[:invoice].company = Company.find(1) # load company
… # other association
end

Then in my view with the command <%= debug(session[:invoice]) %> i can
see
company: # this time is empty… because?

This only for the company association, becouse other association such as
bank perform well.
The name of the field in the database table are correct…
I don’t know where find the solution…

Please, help me. Where i mistake.

–sAndrea