Rails Database Query

Question

I am trying to gather information from a database and then pass that information on to my view via flash. Unfortunately the information is formatting in an ActiveRecord::Relation and not in any format that I can read.

Controller Query

@message = Message.where(:all).limit(4).order(id: :desc).only(:order,:where)    
    flash[:response] = @message
    redirect_to (:back)

If I do something like

@message = Message.where(:all).limit(4).order(id: :desc).only(:order,:where)    
    flash[:response] = @message.first.mess
    redirect_to (:back)

To try and get the first returned value in the mess column, I get an undefined method error. I have been trying to find a tutorial that tells me how to take information once my query has been run but I have not had much luck with Rail's tutorials as of late. I appreciate any help that you guys can give. After I do this I am going to try to format the 4 different results on the view side.

Ruby Racer · Accepted Answer · 2014-06-28 21:14:41Z

1

List of messages:

@messages = Message.order(id: :desc).limit(4)

This: only(:order,:where) cancels your limit(4) (why?)

@messages is now an activerecord association, not suitable to output.... So, if you have 4 messages top you can do:

if @messages.any? # maybe no messages come out
    flash[:response] = @messages.map(&:mess).join('<br>') # add an html newline between them
end
redirect_to :back

answered Jun 28, 2014 at 21:14

Ruby Racer

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9 Comments

user3445138 Over a year ago

So I understand the query as such - SELECT * FROM Messages ORDER by ID DESC LIMIT 4. However my query is not returning anything (I get the error 'undefined method 'any?' for nil:NilClass') I feel as though I understand the code but then I don't understand why I am not getting any result from the query as the syntax seems fine to me.

user3445138 Over a year ago

Sorry submitted by hitting enter by accident

Ruby Racer Over a year ago

Do you have a Message class?

user3445138 Over a year ago

Yes a simple one - class Message < ActiveRecord::Base validates :mess, :presence => true validates :user, :presence => true end

Ruby Racer Over a year ago

Run this in console: Message.order(id: :desc).limit(4), what do you get?

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