我使用的Heroku主办我的Ruby on Rails应用程序和一个或那样的原因，我可能有一些重复的行。

有没有办法基础上删除2个或更多的标准重复的记录，但保留了重复征收的只有1记录？

在我的使用情况下，我在我的数据库中的品牌和型号的关系的汽车。

 品牌型号
--- ---
姓名姓名
          年
          修剪
          MakeId
 

我想删除具有相同的名称，年份所有型号记录和修剪，但保持1的那些记录（的意义，我需要的记录，但只有一次）。我使用Heroku的控制台，这样我可以轻松地运行一些活动记录的查询。

有什么建议？

 类模型

  高清self.dedupe
    ＃找到所有的模型和他们组按键，应该是共同的
    分组= all.group_by {|模型| [model.name，model.year，model.trim，model.make_id]}
    grouped.values​​.each做|重复|
      ＃我们要保持正确的第一个？
      first_one = duplicates.shift＃或流行音乐的最后一个
      ＃如果有更多的离开了，他们是重复
      ＃所以全部删除
      duplicates.each {|双| double.destroy}＃重复的，现在被破坏
    结束
  结束

结束

Model.dedupe
 

找到所有 在小组他们在你需要的唯一性键 循环散列的分组模式的值 因为要保留删除的第一个值的一个副本 删除其余

I'm using Heroku to host my Ruby on Rails application and for one reason or another, I may have some duplicate rows.

Is there a way to delete duplicate records based on 2 or more criteria but keep just 1 record of that duplicate collection?

In my use case, I have a Make and Model relationship for cars in my database.

Make      Model
---       ---
Name      Name
          Year
          Trim
          MakeId

I'd like to delete all Model records that have the same Name, Year and Trim but keep 1 of those records (meaning, I need the record but only once). I'm using Heroku console so I can run some active record queries easily.

Any suggestions?

class Model

  def self.dedupe
    # find all models and group them on keys which should be common
    grouped = all.group_by{|model| [model.name,model.year,model.trim,model.make_id] }
    grouped.values.each do |duplicates|
      # the first one we want to keep right?
      first_one = duplicates.shift # or pop for last one
      # if there are any more left, they are duplicates
      # so delete all of them
      duplicates.each{|double| double.destroy} # duplicates can now be destroyed
    end
  end

end

Model.dedupe

Find All Group them on keys which you need for uniqueness Loop on the grouped model's values of the hash remove the first value because you want to retain one copy delete the rest