Rails Ruby on Rails

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• You flagged this item as spam.
  

  Joris July 30th, 2009 @ 03:57 PM

  So, I read the bar at the right :)
  So, I didn't test this, I just typed it here, so I'm not sure if my manual diff is ok. anyway.. here's the code:

  In base.rb from activerecord:

  in find(*args):
  

      case args.first
        when :first  then find_initial(options)
        when :all    then find_every(options)
  

  •   when :unique then find_unique(options)
    

  add method:
  

      def find_initial(options)
        options.update(:limit => 1) unless options[:include]
        find_every(options).first
      end
  

  •  def find_unique(options)
    

  •    records = find_every(options)
    

  •    if records.size > 0 then
    

  •      raise ActiveRecordError, "Too many records found: #{records.size}"
    

  •    end
    

  •    records.first
    

  •  end
    

  Also, some calls to find_initial should be replaced by find_unique, but I can imagine that would break some existing apps. So that might be for later.

• You flagged this item as spam.
  

  Joris July 30th, 2009 @ 04:01 PM

  So, I read the bar at the right :)
  So, I didn't test this, I just typed it here, so I'm not sure if my manual diff is ok. anyway.. here's the code:

  In base.rb from activerecord:

  in find(*args):
  

          case args.first
  
  
  
  
  
  
  

        when :first  then find_initial(options)
        when :all    then find_every(options)
  

  •   when :unique then find_unique(options)</code>
    

  
  
  
  
  
  add method:
  
  

          def find_initial(options)
  
  
  
  
  
  
  

        options.update(:limit => 1) unless options[:include]
        find_every(options).first
      end
  

  •  def find_unique(options)
    

  •    records = find_every(options)
    

  •    if records.size > 0 then
    

  •      raise ActiveRecordError, "Too many records found: #{records.size}"
    

  •    end
    

  •    records.first
    

  •  end</code>
    

  
  
  
  
  
  Also, some calls to find_initial should be replaced by find_unique, but I can imagine that would break some existing apps. So that might be for later.
  

• 

  Pratik July 30th, 2009 @ 04:58 PM

  Hey Joris,

  I think you should discuss this change in the ML first. Also, your patch should have tests. Check http://guides.rubyonrails.org/contributing_to_rails.html for more details.

  Thanks!

• 

  Pratik July 30th, 2009 @ 05:01 PM

  • State changed from “new” to “incomplete”

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  MatthewRudy July 31st, 2009 @ 11:53 AM

  is this really the proposed implementation?
  

  def find_unique(options)
    records = find_every(options)
    if records.size > 0 then
  
  
  
  
  
  
  

  raise ActiveRecordError, "Too many records found: #{records.size}"
  

  
  
  
  
    end
    records.first
  end
  

  Seems a bit crazy,
  I'd rather have the two db calls (count, and find_first)

  Also, I don't get the use-case.
  Joris, do you have some examples of how you are using this feature?

  The only reason I've needed something similar is this case;

  class SomeSortOfSettings < ActiveRecord::Base
    def self.instance
      self.first || self.new
    end
  end
  

  namely a "Singleton" ActiveRecord,
  but I think there's a better way to deal with this
  (an ActiveRecord::Singleton class, perhaps)

  User.find(:unique, :conditions => {:username => "ralph"})
  

  is silly,
  you should just have a unique key on :username

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  Joris July 31st, 2009 @ 12:00 PM

  Having 2 queries would be a waste of db calls. If you expect 1 row, there's no need to do a count.

  All queries for something with a unique index / natural key is where I'd do this. Just because it's contextual more correct, and it has no performance drawbacks except for a single check if there's another row in the resultset.

  The implementation was just something I typed. I can imagine that there would be some other things that would need to happen, but basically that's how about what I had in mind.

  Hibernate has a similar feature: query.uniqueResult

• 

  Pratik July 31st, 2009 @ 12:01 PM

  • State changed from “incomplete” to “wontfix”

  While I don't think this is gonna make it to the core, but the best implementation would probably be the one using :limit => 2.

  This seem very project specific, hence you should just keep it in /lib or maybe make a plugin and see if many people find it useful or not. We can always reconsider the feature if more people are using it.

  Thanks.

• 

  Ryan Bigg October 11th, 2010 @ 10:55 AM

  • Tag cleared.
  • Importance changed from “” to “Low”

  Automatic cleanup of spam.