带有 Mongo Mapper 的 Rails

Question

事实证明，这是学习 Rails 最糟糕的一天。已经无法连接和配置到 sqlite3、mysql 数据库我转向 mongo mapper 并面临同样的问题。当我尝试启动 rails 服务器时，我得到以下信息：

/usr/local/lib/ruby/gems/1.8/gems/activesupport-3.0.7/lib/active_support/dependencies.rb:239:in `require': no such file to load -- mongo_mapper (LoadError)

我已经安装了 mongo_mapper gem，但是当我执行“which mongo_mapper”时，它不会返回任何东西。

这是我放在初始化程序文件夹中的 mongo_config.rb 文件：

require "rubygems"
require "mongo_mapper"

MongoMapper.database = "blog-#{Rails.env}"

更新1：

我改成如下：

require "rubygems"
include MongoMapper

MongoMapper.database = "blog-#{Rails.env}"

现在我收到以下错误：

   /Users/azamsharp/Projects/railsprojects/blog/config/initializers/mongo_config.rb:2: uninitialized constant MongoMapper (NameError)

Answer 1

您必须将 bundler 与 rails 3 一起使用。不要试图不使用它。将以下内容添加到您的 Gemfile

source 'http://gemcutter.org'
source 'http://rubygems.org'

gem "rails", "3.0.7"
gem 'bson', "1.1.1"
gem 'bson_ext', "1.1.1"
gem 'mongo_mapper'

然后运行

bundle install

那么rails server 就可以了

Answer 2

为了让 mongo_mapper 在 Rails 中工作（在 Rails 3.1 下测试，也应该在 Rails 3.0.x 中工作），您必须遵循以下步骤：

1. 在 Gemfile 中，添加 mongo_mapper 和 bson gem：

   gem 'mongo_mapper'
   gem 'bson_ext'
   

2. 运行捆绑安装

3. 在 config/ 目录下，创建一个像这样的 mongo.yml 文件：

   # config/mongo.yml
   
   defaults: &defaults
     host: 127.0.0.1
     port: 27017
   
   development:
     <<: *defaults
     database: db_development
     username: user
     password: password
   
   test:
     <<: *defaults
     database: db_test
   
   # set these environment variables on your prod server
   production:
     <<: *defaults
     database:
     username:
     password:
   

4. 在 config/initializers 目录中，创建一个 mongo.rb 文件，如下所示：

    # config/initializers/mongo.rb
   
    #include MongoMapper
   
    db_config = YAML::load(File.read(File.join(Rails.root, "/config/mongo.yml")))
    #
    if db_config[Rails.env] && db_config[Rails.env]['adapter'] == 'mongodb'
      mongo = db_config[Rails.env]
      MongoMapper.connection = Mongo::Connection.new(mongo['host'] || 'localhost',
                                                 mongo['port'] || 27017,
                                                :logger => Rails.logger)
      MongoMapper.database = mongo['database']
   
      if mongo['username'] && mongo['password']
        MongoMapper.database.authenticate(mongo['username'], mongo['password'])
      end
    end
   
    # Used for image uploads
    # CarrierWave.configure do |config|
    #   mongo = db_config[Rails.env]
    #   config.grid_fs_database = mongo['database']
    #   config.grid_fs_host = mongo['host'] || 'localhost'
    #   config.grid_fs_access_url = "gridfs"
    #   config.grid_fs_username = mongo['username']
    #   config.grid_fs_password =  mongo['password']
    # end
   
    # It's also possible to define indexes in the the model itself; however,
    # a few issues are being worked out still. This is a temporary solution.
    # Comment.ensure_index([["story_id", 1], ["path", 1], ["points", -1]])
    # MongoMapper.ensure_indexes!
   
    # Handle passenger forking.
    # if defined?(PhusionPassenger)
    #    PhusionPassenger.on_event(:starting_worker_process) do |forked|
    #      MongoMapper.database.connect_to_master if forked
    #    end
    # end
   
    if defined?(PhusionPassenger)
       PhusionPassenger.on_event(:starting_worker_process) do |forked|
         MongoMapper.connection.connect if forked
       end
    end
   

5. 在启动 rails 服务器之前先启动 mongod 服务器，尽情享受吧！

Answer 3

尝试删除需要的行并将其替换为include MongoMapper