Ruby on Rails

Comments and changes to this ticket

• 

  wildchild May 17th, 2008 @ 09:07 PM

  My 5 cents for you (if i right understand your approach):

  ActiveRecord::Base.each.fetch(10) # fetch 10 records instead 1 (for small rows in example)

  Maybe use will_paginate there?

• 

  Guillermo Álvarez May 17th, 2008 @ 08:15 PM

  ActiveRecord::Base.each

  ActiveRecord::Base.map

  ActiveRecord::Base.collect

  With migrations between two or more databases, is common to do something like

  User.find(:all).each {|u| ... } that will load all the records in memmory.

  Ruby-proff says that managing that big array is not the better way.

  For my personal projects I use something like these:

  http://github.com/guillermo/acti...

  User.each :conditions => ["users.created_at > ?", Time.now-5.months] do |u|

  NewUser.schema.create({

  :name => u.name.Capitalize

  :email => validate_email u.email

  ... })

  end

  If someone think it could be interesting, i can try to make a patch.

  Thanks

• 

  Guillermo Álvarez May 17th, 2008 @ 08:24 PM

  My situation is these:

  desc 'Copy Posts from the phpbB3 table to the new forum'

  task :copy_posts => :environment do

  BbTopic.find(:all).each do |bb|

  f = Post.create({

  :title => conv.iconv(bb.topic_title),

  :user_id => bb.topic_poster,

  :forum_id= bb.forum_id,

  ...})

  end

  end

  If i run that i will get a huge array in memory that i doesn't want, so i change

  BbTopic.find(:all).each do |bb|

  to

  BbTopic.each do |bb|

  that just load one record a time.

• 

  Tarmo Tänav May 18th, 2008 @ 06:53 PM

  Something like this has already been proposed:

  http://dev.rubyonrails.org/ticke...

  http://weblog.jamisbuck.org/2007...

• 

  wildchild May 29th, 2008 @ 12:22 AM

  Any progress with ticket?

• 

  Joshua Peek August 29th, 2008 @ 04:41 PM

  • → Tag changed from “” to “enhancement”
  • → State changed from “new” to “stale”
• 

  Guillermo Álvarez September 9th, 2008 @ 01:37 PM

  • → Tag changed from “enhancement” to “activerecord enhancement”

  Hi.

  There is a patch to do for example Post.each.

  Please giveme comments since is my first patch to rails.

  • active_record_each_rails.patch 5.9 KB
• 

  Guillermo Álvarez September 10th, 2008 @ 09:27 AM

  • → Assigned user changed from “” to “Joshua Peek”
• 

  Guillermo Álvarez September 10th, 2008 @ 09:27 AM

  • → Title changed from “ActiveRecord::Base.each instance method” to “[PATCH] ActiveRecord::Base.each instance method”
• 

  Pratik September 10th, 2008 @ 10:31 AM

  • → Tag changed from “activerecord enhancement” to “activerecord enhancement patch”
  • → Title changed from “[PATCH] ActiveRecord::Base.each instance method” to “ActiveRecord::Base.each instance method”
• 

  Jeremy Kemper September 10th, 2008 @ 06:12 PM

  • → Milestone changed from “” to “2.2”
  • → State changed from “stale” to “open”
• 

  Joshua Peek September 10th, 2008 @ 06:30 PM

  • → Assigned user changed from “Joshua Peek” to “Jeremy Kemper”
• 

  Pratik October 17th, 2008 @ 05:13 PM

  • → Milestone changed from “2.2” to “2.x”
• 

  José Valim October 19th, 2008 @ 11:36 AM

  Hi Guillermo Álvarez,

  Would not be nice if your patch takes into account the option :limit and :interval?

  For example:

  @@@ruby Account.each(:interval => 10) do |account|

  # ...
  
  

  end

  
  
  This would query the database using 10 in 10 objects.
  
  The limit would be used if I don't want to go through all the database:
  
  @@@ruby
    Account.each(:interval => 10, :limit => 100) do |account|
      # ...
    end
  

  I have an implementation that I use on my projects (it's not totally abstracted as in your patches), but if it helps:

  @@@ruby def slow_each(options = {})

  total = options.delete(:limit) || self.count(:conditions => options[:conditions])
  options[:limit] = options.delete(:interval) || 1000
  offset = 0
  
  while total - offset > 0
    options[:offset] = offset
  
    self.find(:all, options).each do |record|
      yield(record)
    end
  
    offset += options[:limit]
  end
  
  

  end

  
  
  For fast each, we can use:
  
  @@@ruby
    def fast_each(options = {})
      total = options.delete(:limit) || self.last.id
      default_conditions = options.delete(:conditions)
      options[:limit] = options.delete(:interval) || 1000
      offset = 0
  
      while total - offset > 0
        options[:conditions] = self.__send__(:merge_conditions, default_conditions, ['id BETWEEN ? AND ?', offset + 1 , offset + options[:limit]])
  
        self.find(:all, options).each do |record|
          yield(record)
        end
  
        offset += options[:limit]
      end
    end