Associations Confusion

Rails
1

Guys,very well:

I have the table Empresas:

id: int
(…)

and table Usuarios:

id: int
empresa_id: int
(…)

In models, I makining the follow:

  1. class Empresa < ActiveRecord::Base
  2. has_many :usuario
  1. class Usuario < ActiveRecord::Base
  2. belongs_to :empresa

In partial form, I makeing thus:

<% form_for :empresa, @empresa, :url => {:action => ‘create’} do |emp|
%>

(…)

<% fields_for :usuario, @empresa.usuario do |usr|%>
<table>
  <tr>
    <td>Nome:</td>
    <td><%= usr.text_field :nome %></td>
  </tr>

(…)

That return the follow error:

undefined method `nome’ for Usuario:Class

However, if I to invert the associations in models, for example:

  1. class Empresa < ActiveRecord::Base
  2. belongs_to:usuario
  1. class Usuario < ActiveRecord::Base
  2. has_many :empresa

In this way it functioned correct, now my question. I have a “empresa”
with many “usuarios”(has_many ok?), and many “usuario” belogs of one
“empresa”(belongs_to ok?). Why the logic it is contrary? Or I make a
mistake?

And more, want I save “empresa”, not save “usuario”, only “empresas”!!!
:[

Razão social: <%= emp.text_field :razao_social %>
2

up

3

Doing @emresa.usiario doesn’t work for new records, I think.

Try doing @usiario = @emresa.usiario.new, and <% fields_for :usuario,
@usuario do |usr|%>.

Not sure, though, but try it.

On Jan 18, 3:51 pm, Marcelo J. [email protected]

4

[email protected] wrote:

Doing @emresa.usiario doesn’t work for new records, I think.

Try doing @usiario = @emresa.usiario.new, and <% fields_for :usuario,
@usuario do |usr|%>.

Not sure, though, but try it.

On Jan 18, 3:51 pm, Marcelo J. [email protected]

Well, I make:

(…)
@empresa = Empresa.new(params[:empresa])
@usuario = @empresa.usuario.new
if @empresa.save and @usuario.save
(…)

and
(…)
<% fields_for :usuario, @usuario do |usr|%>
(…)

But appear the follow message when save:
undefined method `usuario’ for #Empresa:0x6705aac

Why?

5

Forgot it was a has_many, go @usiario = @empresa.usiarios.new (plural
of usiario)

On Jan 18, 4:57 pm, Marcelo J. [email protected]

6

[email protected] wrote:

Forgot it was a has_many, go @usiario = @empresa.usiarios.new (plural
of usiario)

On Jan 18, 4:57 pm, Marcelo J. [email protected]

Well, now save only “empresa”, but not “usuario”.

I make action thus:

def create
@empresa = Empresa.new(params[:empresa])
@usuario = @empresa.usuarios.new
if @empresa.save and @usuario.save
rendirect_to :controller => ‘login’, :action => ‘index’
else
render :action => ‘new’
end
end

???

7

Marcelo J. wrote:

[email protected] wrote:

Forgot it was a has_many, go @usiario = @empresa.usiarios.new (plural
of usiario)

On Jan 18, 4:57 pm, Marcelo J. [email protected]

Well, now save only “empresa”, but not “usuario”.

I make action thus:

def create
@empresa = Empresa.new(params[:empresa])
@usuario = @empresa.usuarios.new
if @empresa.save and @usuario.save
rendirect_to :controller => ‘login’, :action => ‘index’
else
render :action => ‘new’
end
end

???

it forgives me!!! Not was saving because of “validates”. The “empresa”
and “usuario” now they are saving, but de field “empresa_id” of
“usuario” it is null. How make for save empresa id? @usuario.empresa_id
= @empresa.id? Not have make this using only associations?

8

Hi Marcelo.

You should be using the build method provided by has_many instead of
new. That way the usuario-empresa relationship is created (the
empresa_id is assigned). Using new just creates a new usuario. The line
should look like this

@usuario = @empresa.usuarios.build

If you want to fill the usuario with the form data you could do

@usuario = @empresa.usuarios.build(params[:usuario])

In any case, using the build method will make AR save the usuario when
you save the empresa, so there will be no need to do usuario.save

Regards

Marcelo J.
escribió:>

???

it forgives me!!! Not was saving because of “validates”. The “empresa”
and “usuario” now they are saving, but de field “empresa_id” of
“usuario” it is null. How make for save empresa id? @usuario.empresa_id
= @empresa.id? Not have make this using only associations?

–
Andrés Cirugeda E.
ASPgems
Email: andres at aspgems dot com

‘All we have to decide is what to do with the time that is given to us’.
Gandalf.