ruby-on-rails – 在轨道中合并两个/三个记录

@user1 = User.find(1);
@user2 = User.find(2);

Contact.where("user_id = ?",@user2.id).update_all(:user_id => @user1.id)
@user2.destroy

在一般化解决方案的情况下
放置文件/lib/acts_as_user_merge.rb

module UserMerge
  module ActsAsUserMerge
    module Base
      def self.included(klass)
        klass.class_eval do
          extend Config
        end
      end
    end

    module Config
        def acts_as_user_merge
            include ::UserMerge::ActsAsUserMerge::InstanceMethods
        end
    end

    module InstanceMethods    
      def merge(user)
        models = Array.new
        models_names = User.reflections.collect{|a,b| b.class_name if b.macro==:has_many}.compact
        models_names.each do |name|
          models << Object.const_get name
        end
        models.each do |model|
          model.where("user_id = ?",user.id).update_all(:user_id => self.id)
        end
        user.destroy
      end
    end
  end
end

::ActiveRecord::Base.send :include,::UserMerge::ActsAsUserMerge::Base

如何使用

User < ActiveRecord::Base
  has_many ...

  acts_as_user_merge

end

@user1.merge(@user2)

有点凌乱,没有经过测试,但应该给你一个想法