Question

这是学习铁路的最糟糕的一天。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，我得到以下内容：

/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'mongo_mapper'时它不会返回任何内容。

这是我的mongo_config.rb文件放在initializers文件夹中：

require "rubygems"
require "mongo_mapper"

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

更新1：

我改为：

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

然后rails server将起作用

Answer 2

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

在Gemfile中，添加mongo_mapper和bson gem：
```
gem 'mongo_mapper'
gem 'bson_ext'
```
运行捆绑安装

在config /目录中，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:

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

在启动rails服务器之前启动mongod服务器并享受！

Answer 3

尝试删除require行并将其替换为include MongoMapper

使用Mongo Mapper的Rails

3 个答案: