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Ruby on Rails: NoMethodError in Controller#action – Undefined method ‘each’

I set an instance variable by running the following query:

@some_list = Model.find_by_column_name(nil)

I tried to interate the content of @some_list and received the following error:

NoMethodError in Controller#action

Showing app/views/model/list.rhtml where line [line number] raised:

undefined method `each’ for #…

Apparently, I just need to add “_all_” in the query:

@some_list = Model.find_all_by_column_name(nil)

Easy solution, eh? :)

Update: I found the solution after I looked at the back-end SQL query.

Task Load (0.000354) SELECT * FROM table WHERE [some condition] LIMIT 1

After I added “_all_” in the statement, I finally get the right query.

Task Load (0.000332) SELECT * FROM table WHERE [some condition]

This entry was posted on Tuesday, November 27th, 2007 at 1:30 am and is filed under Ruby on Rails, Software Development, Web Development. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.

4 Responses to “Ruby on Rails: NoMethodError in Controller#action – Undefined method ‘each’”

  1. shaun Says:
    May 8th, 2008 at 4:02 pm

    i can’t believe i missed that. Thanks for the post.

  2. Handy Says:
    May 8th, 2008 at 11:32 pm

    You’re welcome. It’s easy to fall into the trap hence I created this post. :)

  3. fididle Says:
    January 3rd, 2009 at 8:07 pm

    Thanks. This helped me to.

    I was seeing a similar NoMethodError with

    @examples = example.find(:first)

    in the controller, which resulted
    in the following SQL (see your web server console output):

    SELECT * FROM `examples` LIMIT 1

    Apparently the corresponding “each” method in my views/index.html.erb file
    (below) doesn’t work on a single record.

    % @examples.each do |c| %>
    ’show’ } %>

    When I changed the contoller method to:

    @examples = example.find(:all)

    The LIMIT 1 was no longer in the SQL query:

    SELECT * FROM `examples`

    And “each” worked.

  4. Handy Says:
    January 4th, 2009 at 4:28 am

    You’re welcome. :)
    I’m glad my post helped you.

    I’m trying to post the problems and the solutions in this blog. :)

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