Undefined method `update_attributes'?

Question

Why do I get this error? I'm out of ideas.

undefined method `update_attributes' for #

Code:

exists = Vote.where(comment_id: @comment.id).exists?
    if exists
        update_vote = Vote.where(comment_id: @comment.id)
        update_vote.update_attributes(value: 5)
        redirect_to :back
    else

What this error message tells you is that your update_vote.update_attributes is not defined. Somewhere earlier in your code, you should define update_attributes, otherwise you can't use it here. — Joeytje50
– Joeytje50, Commented Jan 27, 2014 at 22:10

apneadiving · Accepted Answer · 2014-01-27 21:47:54Z

8

You want to fetch one record in particular, so tell it:

update_vote = Vote.where(comment_id: @comment.id).first

but this code is prone to errors if nothing matches, beware.

answered Jan 27, 2014 at 21:47

apneadiving

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Comments

take · Accepted Answer · 2014-02-18 00:36:46Z

1

Try using find_by instead of where. It will return one document instead of a Mongoid::Criteria, which is why you're getting that error (you're trying to run .update_attributes, which acts on a single record, on a group of records). Consider the following instead.

if update_vote = Vote.find_by(comment_id: @comment.id)
  update_vote.update_attributes(value: 5)
  redirect_to :back
else

The above code can also avoid an unnecessary call to .exists? since the existence check is right along with the definition (if .find_by does not find any records that match, it returns nil, much like .where(...).first would also do).

answered Feb 18, 2014 at 0:36

take

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