From: Robert Klemme <bob.news@...>
Date: 2005-11-16T02:27:17+09:00
Subject: Re: Database Transactions

listrecv@gmail.com wrote:
> Okay, I'll trust you guys know better than I do.
> How do I do this with a block?

http://wiki.rubyonrails.com/rails/pages/HowToUseTransactions

>   def signup
>   # It gets a little tricky, since we want to create either both an
> account and user or neither
>
>     @account = Account.new(params[:account])
>     @user = User.new(params[:user])
>     @user.login = @account.code # For now, we keep a 1-to-1 between
> these
>     @user.real_name = @account.name
>
>     begin
>     # TODO begin transaction
>     if (@user.valid?)
>     @account.user = @user # Don't assign until we know it is valid -
> ActiveRecord sometimes saves on assign
>     if (@account.valid?) # We need to do this in two steps, since
> @account won't be valid without a user
>     @user.save!
>     @account.save!
>     # TODO end transaction
>     flash[:notice] = 'Account added.'
>       redirect_to :action => 'list'
>       return
>     end
>     end
>     # TODO rollback transaction

Why do you want to do a rollback here?  There is no rescue clause nor any
indication that an error has occurred.  If you use a block then you don't
need explicit commit and rollback.  It's handled in the method that
receives the block (#transaction).

>      render :action => 'new'
> # TODO rescue exceptions
> end
>   end
>
>
> (Okay, I admit it, yes, this is part of a rails app...)

I know only little about RoR so there might as well be other answers.

Kind regards

    robert