mongodb = MongoMapper.database
collection = mongodb.collection("my_collection")
collection.find.first
=> {"_id"=>BSON::ObjectId('4e43dfc75d1e1e0001000001'),"key1"=>"val1" }

这个其他的SO Q / A更直接,使用像MongoMapper.database.eval(Mongo::Code.new(‘function(){ return 11 + 6; })这样的javascript函数

[/更新]

我有这样的多语言架构,一些模型使用postgresql,其他模型使用mongo文档.我不太确定你在问什么,所以我会直接跳进去发布我的大部分配置.它包括我的黑客,你可能在其他地方找到更漂亮的配置.

我把设置放在一个要点
https://gist.github.com/957341

好的,所以这是一个带有嵌入式文档的文档,然后是规范.我一个接一个地写了这些规格,所以它们有点受试验驱动.

class MyDocument
  include MongoMapper::Document
  key :title,String
  key :published_at,Time,:index => true
  key :collaborators,Array

  many :my_embedded_documents
end
class MyEmbeddedDocument
  include MongoMapper::EmbeddedDocument
  key :title,String
  key :author,String
  embedded_in :my_document
end

规范

require "spec_helper"

describe MyDocument do

  before do
    @md = MyDocument.create(:title => "Example",:collaborators => ["mongomapper","rspec","oma"] )
  end
  it "should have title" do

    found = MyDocument.find(@md.id)
    found.title.should == "Example"
  end

  it "should have two my_documents" do
    MyDocument.create
    MyDocument.count.should == 2
  end

  it "should be able to fetch embedded documents" do
    @md.my_embedded_documents << MyEmbeddedDocument.new(:title => "The King",:name => "Elvis Presley")
    @md.my_embedded_documents.build(:title => "Embedded example",:name => "Embeddo")
    @md.save!
    MyDocument.where(:title => "Example").first.should == @md #findMyEmbeddedDocument.count.should == 2
  end

end

spec_helper.rb

RSpec.configure do |config|
  #...
  config.after(:each) do
    MongoMapper.database.collections.each(&:remove)
  end
end

我不知道你想要什么答案,但我希望这会对某人有所帮助.