的Heroku：耙分贝：迁移失败，MongoDB的

Question

运行heroku run rake db:migrate和得到的错误：

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. 

当地一切正常。我有一个mongoid.yml文件，其中包含配置蒙戈并创建了一个mongohq蒙戈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 

我试图寻找一个解决方案或者对如何没有成功修复任何方向。我究竟做错了什么？

编辑：我加入include Rake::DSL我的Rake文件，现在初步警告走了，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) 

Answer 1

我想你错过：

adapter: mongodb 

这里是我的设置为postgres database.yml：

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

你可能想看看这篇文章，以及：

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