# Newbie question: updating a child row from a form

**URL:** <https://www.ruby-forum.com/t/newbie-question-updating-a-child-row-from-a-form/92457>\
**Category:** Rails\
**Created:** [April 19, 2007, 5:48pm UTC](https://www.ruby-forum.com/t/newbie-question-updating-a-child-row-from-a-form/92457 "2007-04-19T17:48:37Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![emilsebastian](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/7ba0ec/32.png) [@emilsebastian](https://www.ruby-forum.com/u/emilsebastian)\
**Post date:** [April 19, 2007, 5:48pm UTC](https://www.ruby-forum.com/t/newbie-question-updating-a-child-row-from-a-form/92457/1 "2007-04-19T17:48:37Z")

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Hi,  
I have two models in my application, User and Profile, looking like  
this:

class User \< ActiveRecord::Base  
has\_one :profile, :dependent =\> :destroy  
end

class Profile \< ActiveRecord::Base  
belongs\_to :user  
end

What I want to do is to be able to edit a user object instance and the  
associated profile from the same form. I’ve tried to reference the  
profile in my view template as can be seen below (my edit action  
instantiates a @user variable with data from the db).

\<%= text\_area ‘user.profile’, ‘about\_message’, :cols =\> 20, :rows =\> 3  
%\>

However, when I try to load the page in my browser I get an error:  
`@user.profile’ is not allowed as an instance variable name

I then choosed to add a @profile variable and reference it instead.

\<%= text\_area ‘profile’, ‘about\_message’, :cols =\> 20, :rows =\> 3 %\>

This works for the view part, but my controller code doesn’t behave as  
expected. Here’s what I try to do:

@user.attributes = params[:user]  
@user.profile.attributes = params[:profile]  
@user.save

I’ve read in AWDWR that Active Record automatically saves dependent  
child rows when the parent row is saved (and wraps the inserts/updates  
in a transaction), but for some reason I can’t get it to work. Only the  
changes to the user object are saved …

After some googling I decided to use the “update\_attributes” method and  
since I make two separate database calls I’ve wrapped them in a  
transaction.

begin  
transaction do  
@user.update\_attributes(params[:user])  
@profile.update\_attributes(params[:profile])  
end  
rescue  
success = false  
end

This worked eventually, but intuitively it doesn’t feel like the right  
way to solve the problem. What do I need to do to have the profile being  
saved automatically when the user is saved? Is it possible at all?

What I would like to be able to do is something like either:  
1)  
View:  
\<%= text\_area ‘user.profile’, ‘about\_message’, :cols =\> 20, :rows =\> 3  
%\>

Action:  
@user.update\_attributes(params[:user])

or

1. 

View:  
\<%= text\_area ‘profile’, ‘about\_message’, :cols =\> 20, :rows =\> 3 %\>

Action:  
@user.attributes = params[:user]  
@user.profile.attributes = params[:profile]  
@user.save

Any help to shed some light on this is much appreciated. Cheers