users enter results only once

I have this script in my results controller:

 distribution_sheet = DistributionSheet.find(:all, :conditions => ["lifecycle_state = ?","open"]).last


   if distribution_sheet.nil?
     redirect_to root_path  #you could redirect somewhere else if you want
      flash[:notice] = "There are currently no active EQAs"
  # elsif (@result.size > 1)
  #   redirect_to root_p开发者_如何学JAVAath  #you could redirect somewhere else if you want
   #   flash[:notice] = "You have already entered your EQA for EQA number #{distribution_sheet.id}"
    else
    flash[:notice] =      "EQA number #{distribution_sheet.id} is open for submissions"
  end

result is a model. I need the users to input new results when the DistributionSheet is 'open' ONLY ONCE. The elsif above doesnt seem to work. Any advice?

Here is where the @result was referenced:

    def new
   @result = Result.new
   distribution_sheet = DistributionSheet.find(:all, :conditions => ["lifecycle_state = ?","open"]).last
   @result.distribution_sheet_id = distribution_sheet.id
  10.times do
            @result.specimen_results.build

  end
  specimen_ids  = distribution_sheet.specimens.collect{|specimen| specimen.id}
  @result.specimen_results.each do |specimen_result|
        specimen_result.specimen_id = specimen_ids.shift
  end

   @result.lab_id = current_user.lab_id

  end

---

A couple of things. By doing this:

 distribution_sheet = DistributionSheet.find(:all, :conditions => ["lifecycle_state = ?","open"]).last

You're loading the every single DistributionSheet object in your database that meets those conditions. It may seem quick now, but when you've got a ton of records it will take a while. Best to do this instead:

distribution_sheet = DistributionSheet.first(:conditions => "lifecycle_state = 'open'", :order => "id DESC")

That'll accomplish the same goal but won't load the entire association first of all, just the one record you need.

Secondly, perhaps rather than checking @result.size > 1 you should be checking it on the association instead:

distribution_sheet.results.count > 1

This will do an SQL query to count the number of results for a distribution_sheet object. You need to have a has_many :results in the DistributionSheet model first.

So a couple more things: I would recommend reading the Getting Started guide as well as the Association Basics guide to learn the basics you need in order to solve this problem correctly.