heroku: rake db:migrate 使用 mongoDB 失败答案

【问题标题】：heroku: rake db:migrate fails with mongoDBheroku: rake db:migrate 使用 mongoDB 失败
【发布时间】：2012-11-26 06:37:34
【问题描述】：

运行 heroku run rake db:migrate 并得到错误：

Running `rake db:migrate` attached to terminal... up, run.9259
DEPRECATION WARNING: railtie_name is deprecated and has no effect. (called from <top (required)> at /app/config/application.rb:10)
WARNING: Global access to Rake DSL methods is deprecated.  Please include
    ...  Rake::DSL into classes and modules which use the Rake DSL methods.
WARNING: DSL method Quora::Application#task called at /app/vendor/bundle/ruby/1.9.1/gems/railties-3.0.5/lib/rails/application.rb:214:in `initialize_tasks'
rake aborted!
Database should be a Mongo::DB, not NilClass.

本地一切运行良好。我有一个 mongoid.yml 文件，其中包含 mongo 的配置，并使用 mongohq 创建了一个 mongo db：

defaults: &defaults
  host: '127.0.0.1'
  autocreate_indexes: false
  allow_dynamic_fields: true
  include_root_in_json: false
  parameterize_keys: true
  persist_in_safe_mode: false
  raise_not_found_error: true
  reconnect_time: 3

development:
  <<: *defaults
  database: mydb_development

development_mongohq:
  <<: *defaults
  #use demo mongohq database for fast run
  uri: mongodb://user:pass@linus.mongohq.com:10016/app9861715

test:
  <<: *defaults
  database: quora_test

# set these environment variables on your prod server
production:
  <<: *defaults
  host: '127.0.0.1'
  database: mydb

我已尝试寻找解决方案或任何有关如何解决的方向，但均未成功。我做错了什么？

编辑：我将 include Rake::DSL 添加到我的 Rakefile 中，现在最初的警告消失了，但我仍然得到：

heroku run rake db:migrate
Running `rake db:migrate` attached to terminal... up, run.4751
DEPRECATION WARNING: railtie_name is deprecated and has no effect. (called from <top (required)> at /app/config/application.rb:11)
rake aborted!
Database should be a Mongo::DB, not NilClass.

Tasks: TOP => db:migrate => environment
(See full trace by running task with --trace)

【问题讨论】：

标签： ruby-on-rails mongodb heroku mongohq

【解决方案1】：

我认为你不见了：

adapter: mongodb

这是我对 postgres database.yml 的设置：

development: 
  adapter: postgresql
  encoding: unicode
  database: db
  pool: 50
  username: user
  password: pwd
  host: localhost

你可能也想看看这篇文章：

https://stackoverflow.com/a/6757749/169277

【讨论】：

嘿@ant 我相信 mongoid 是完全替代品而不是适配器