编辑：一般建议是使用 CEDAR 堆栈。
RoR，Gems，Heroku和Git相当新鲜。以下教程：http://ruby.railstutorial.org/book/ruby-on-rails-tutorial
在localhost上顺利运行，当部署到Heroku时出现 ConnectionNotEstablished错误，这在此解决了： https://stackoverflow.com/questions/7542745/heroku-error-activerecordconnectionnotestablished （顺便说一下：遵循相同的教程）将生产数据库更改为PostgreSQL （gem'pg'）之后会产生另一个错误：
访问实时网站
应用程序中发生错误，您的页面无法执行 提供服务。请稍后再试。
如果您是应用程序所有者，请查看日志以获取详细信息。
试过这个 - Heroku app crashed, receiving "Invalid DATABASE URL" when attempting heroku rake db:migrate - heroku rake db：migrate
rake aborted!
Invalid DATABASE_URL
Tasks: TOP => db:migrate => db:load_config
(See full trace by running task with --trace)
heroku console
Internal server error
的Gemfile
source 'http://rubygems.org'
gem 'rails', '3.1.1'
group :development do
gem 'rspec-rails', '2.6.1'
gem 'annotate', '~> 2.4.1.beta'
gem 'sqlite3'
end
group :test do
gem 'rspec-rails', '2.6.1'
gem 'webrat', '0.7.1'
gem 'sqlite3'
end
group :production do
gem 'pg'
end
group :assets do
gem 'sass-rails', '~> 3.1.4'
gem 'coffee-rails', '~> 3.1.1'
gem 'uglifier', '>= 1.0.3'
end
heroku日志
9:02+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:143:in `run!'
9:02+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/bin/thin:6:in `<top (required)>'
9:02+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
9:02+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:18:in `block (2 levels) in <main>'
9:02+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `initialize'
9:02+00:00 app[web.1]: from /usr/ruby1.9.2/bin/thin:19:in `<main>'
9:02+00:00 app[web.1]: from /usr/ruby1.9.2/bin/thin:19:in `load'
9:03+00:00 heroku[web.1]: State changed from starting to crashed
9:04+00:00 heroku[web.1]: Process exited
1:58+00:00 heroku[slugc]: Slug compilation started
3:09+00:00 heroku[api]: Deploy 3dea426 by mstefanow@gmail.com
3:09+00:00 heroku[api]: Release v7 created by mstefanow@gmail.com
3:09+00:00 heroku[web.1]: State changed from crashed to created
3:09+00:00 heroku[web.1]: State changed from created to starting
3:10+00:00 heroku[slugc]: Slug compilation finished
3:12+00:00 heroku[web.1]: Starting process with command `thin -p 44881 -e production -R /home/heroku_rack/heroku.ru start`
3:15+00:00 app[web.1]: (erb):9:in `rescue in <main>': Invalid DATABASE_URL (RuntimeError)
3:15+00:00 app[web.1]: from (erb):6:in `<main>'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/1.9.1/erb.rb:753:in `eval'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/1.9.1/erb.rb:753:in `result'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/application/configuration.rb:106:in `database_configuration'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activerecord-3.1.1/lib/active_record/railtie.rb:68:in `block (2 levels) in <class:Railtie>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/lazy_load_hooks.rb:42:in `each'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activerecord-3.1.1/lib/active_record/base.rb:2190:in `<top (required)>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `block in require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:225:in `load_dependency'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:489:in `load_missing_constant'
3:15+00:00 app[web.1]: from /app/app/models/user.rb:12:in `<top (required)>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:179:in `each'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:179:in `const_missing'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/inflector/methods.rb:124:in `block in constantize'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/inflector/methods.rb:123:in `each'
3:15+00:00 a
from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/inflector/methods.rb:123:in `constantize'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/core_ext/string/inflections.rb:43:in `constantize'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:348:in `require_or_load'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:181:in `block in const_missing'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.1.1/lib/action_controller/metal/params_wrapper.rb:148:in `_default_wrap_model'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.1.1/lib/action_controller/metal/params_wrapper.rb:167:in `_set_wrapper_defaults'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.1.1/lib/action_controller/metal/params_wrapper.rb:128:in `inherited'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.1.1/lib/abstract_controller/railties/routes_helpers.rb:7:in `block (2 levels) in wi
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/actionpack-3.1.1/lib/action_controller/railties/paths.rb:7:in `block (2 levels) in with'
3:15+00:00 app[web.1]: from /app/app/controllers/users_controller.rb:1:in `<top (required)>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `block in require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:225:in `load_dependency'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:240:in `require'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:348:in `require_or_load'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:302:in `depend_on'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/activesupport-3.1.1/lib/active_support/dependencies.rb:214:in `require_dependency'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/engine.rb:417:in `block (2 levels) in eager_load!'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/engine.rb:416:in `each'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/engine.rb:416:in `block in eager_load!'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/engine.rb:414:in `each'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/engine.rb:414:in `eager_load!'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/application/finisher.rb:51:in `block in <module:Finisher>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/initializable.rb:30:in `instance_exec'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/initializable.rb:30:in `run'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/initializable.rb:55:in `block in run_initializers'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/initializable.rb:54:in `each'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/initializable.rb:54:in `run_initializers'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/application.rb:96:in `initialize!'
3:15+00:00 app[web.1]: from /app/config/environment.rb:5:in `<top (required)>'
3:15+00:00 app[web.1]: from <internal:lib/rubygems/custom_require>:29:in `require'
3:15+00:00 app[web.1]: from <internal:lib/rubygems/custom_require>:29:in `require'
3:15+00:00 app[web.1]: from config.ru:3:in `block (3 levels) in <main>'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:23:in `eval'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:23:in `block (3 levels) in <main>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/railties-3.1.1/lib/rails/railtie/configurable.rb:30:in `method_missing'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:120:in `new'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:120:in `map'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:18:in `block (2 levels) in <main>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `instance_eval'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `initialize'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:11:in `new'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `instance_eval'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `initialize'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:11:in `block in <main>'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `instance_eval'
3:15+00:00 app[web.1]: from /app/.bundle/gems/ruby/1.9.1/gems/rack-1.3.6/lib/rack/builder.rb:51:in `initialize'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:1:in `new'
3:15+00:00 app[web.1]: from /home/heroku_rack/heroku.ru:1:in `<main>'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `eval'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/rack/adapter/loader.rb:36:in `load'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:175:in `load_rackup_config'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/controllers/controller.rb:65:in `start'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:143:in `run!'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/bin/thin:6:in `<top (required)>'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/bin/thin:19:in `load'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/bin/thin:19:in `<main>'
3:15+00:00 app[web.1]: from /usr/ruby1.9.2/lib/ruby/gems/1.9.1/gems/thin-1.2.6/lib/thin/runner.rb:177:in `run_command'
3:16+00:00 heroku[web.1]: State changed from starting to crashed
3:17+00:00 heroku[web.1]: Process exited
5:55+00:00 heroku[router]: Error H10 (App crashed) -> GET high-wind-7473.heroku.com/pages/home dyno= queue= wait= service= status=503 bytes=
5:57+00:00 heroku[router]: Error H10 (App crashed) -> GET high-wind-7473.heroku.com/pages/home dyno= queue= wait= service= status=503 bytes=
当然
bundle install
git add .
git commit -m "another heroku fix"
git push
git push heroku
答案 0 :(得分：18)
您需要将DATABASE_URL环境变量设置为在线postgres db的路径。
尝试运行heroku pg。如果输出是“myapp没有heroku-postgresql数据库”。那么你需要先添加PostgreSQL插件。它将在Amazon AWS上为您创建一个postgres数据库。
heroku addons:add heroku-postgresql:hobby-basic
（爱好 - 基本是免费计划）
要查找新数据库的URL，请运行
heroku config
您应该会看到一个以HEROKU_POSTGRESQL开头的变量。复制其值（应以postgres://开头，并使用它来设置DATABASE_URL
heroku config:set DATABASE_URL=postgres://your-db-url
答案 1 :(得分：3)
我有完全相同的问题。事实证明我没有与该应用程序相关联的数据库。您将通过简单的heroku config命令看到这一点 - 您应该会看到一些指向Amazon的数据库URL。例如：
$ h config
DATABASE_URL => postgres://fakedexgwa:fakepassword@ec2-33-44-55-77.compute-1.amazonaws.com/fakedexgwa
无论如何，我通过创建一个全新的应用来解决这个问题并进行部署。我尝试在配置屏幕中摆弄，但无法解决问题。
我不确定这是否与您的原因相同：我创建了一个简单的Ruby应用程序，部署它，然后创建了一个Rails应用程序。我还没有进入任何数据库，我想知道Heroku是否在第一次部署时决定我不需要数据库。
答案 2 :(得分：2)
我首先要做的是将您的应用程序移动到Cedar Stack - 它支持开箱即用的Rails 3.1，而不必进行任何混乱。
当您通过heroku create创建应用时，请将其作为
heroku create --stack cedar
然后重新回到这个堆栈 - 你可能会发现你的问题都会消失。要记住的是在命令中添加“run”，heroku运行控制台，heroku运行rake db：migrate等。
答案 3 :(得分：2)
在配置文件中设置DATABASE_URL的另一种方法是运行命令
heroku pg:promote HEROKU_POSTGRESQL_COLOR_URL
根据rodrei
的建议，将从运行heroku配置中获取.._ COLOR_URL请参阅heroku文档： https://devcenter.heroku.com/articles/heroku-postgresql#establish-primary-db
答案 4 :(得分：1)
请阅读这篇文章：
命令：
heroku config
或者如果您使用一个rails项目多个heroku项目
heroku config --app your_app_name
添加数据库网址：
heroku config：设置DATABASE_URL =＆＃39; mysql：// adffdadf2341：adf4234@us-cdbr-east.cleardb.com/heroku_db？reconnect = true＆＃39;
如果你使用mysql2 gem必须用mysql2替换mysql
heroku config：set DATABASE_URL =＆＃39; mysql2：// adffdadf2341：adf4234@us-cdbr-east.cleardb.com/heroku_db？reconnect = true＆＃39;
我希望这些配置可以用于PostgreSQL，NoSQL数据库或其他数据库。
答案 5 :(得分：0)
请输入heroku config --long - （应用名称）。请发布结果，尤其是DATABASE_URL。
需要更多信息。此外，绝对确保你如上所述在雪松堆上。