Forum: Ruby on Rails Undefined method exists?

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Mike C (Guest)
on 2008-11-10 12:21
(Received via mailing list)
I'm getting the error that exists? is an undefined method when I try
and use it in a model. Basically, it's something like this:

if exists? :user_id => current_user.id

From what I understand, exists? is in ActiveRecord::Base so a model
should be able to use it, right? I've used find() successfully, so why
not exists? It works if I do User.exists?, but not if I do just
exists? which is odd...anyone have an answer to this?
Frederick C. (Guest)
on 2008-11-10 12:32
(Received via mailing list)
On 10 Nov 2008, at 10:20, Mike C wrote:

>
> I'm getting the error that exists? is an undefined method when I try
> and use it in a model. Basically, it's something like this:
>
> if exists? :user_id => current_user.id
>
> From what I understand, exists? is in ActiveRecord::Base so a model
> should be able to use it, right? I've used find() successfully, so why
> not exists? It works if I do User.exists?, but not if I do just
> exists? which is odd...anyone have an answer to this?

It's a class method not an instance method.

Fred
Mike C (Guest)
on 2008-11-10 19:16
(Received via mailing list)
So what's the proper way to use it? self.exists? doesn't work
either...can I only do User.exists??

On Nov 10, 2:31 am, Frederick C. <removed_email_address@domain.invalid>
Frederick C. (Guest)
on 2008-11-10 19:29
(Received via mailing list)
On 10 Nov 2008, at 17:16, Mike C wrote:

>
> So what's the proper way to use it? self.exists? doesn't work
> either...can I only do User.exists??

Yum. That's what it means for a method to be a class method: you call
it on a class not an instance of the class.

Fred
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