From: Stefan Mahlitz <stefan@...>
Date: 2007-02-25T09:08:48+09:00
Subject: Re: Testing a query result

Phrogz wrote:
> On Feb 24, 11:28 am, Mahmou M'hiri <mahmoud.mh...@gmail.com> wrote:
>> It's a very basic question, i want just to test if this query did return
>> any result.
>>
>>          @BookDetails = Book.find(params[:id])
> 
> You will probably get better results asking this question on the Ruby
> on Rails discussion forum. You have instead asked it on the ruby-talk
> mailing list.

I actually think that this is an ActiveRecord question. Does this
qualify for a redirect to rails (even if params[:id] is a good hint)?

I have to admit that I do not know whether rails does change this behaviour.

Do we cover ActiveRecord questions on ruby-talk?


To answer the original question:

ActiveRecord will raise an ActiveRecord::RecordNotFound exception which
you can detect/catch via

begin
  @BookDetails = Book.find(params[:id])
rescue ActiveRecord::RecordNotFound
  # the query did not return a result
end

Stefan