Ruby on Rails 命令 rake db:migrate 无法使用 PostgreSQL 工作

Question

正如我在标题中提到的，我在 Ruby on Rails 上使用 PostgreSQL 数据库，因为 heroku 不再支持 MySQLite。在我运行命令

rails generate scaffold User name:string email:string

后，一切都很顺利，但是当我尝试

rake db:migrate

时，它抛出了一些错误。经过一段时间的搜索后，我将 Rake 从 10.0.1 降级到 0.8.7。这是我使用 --trace 时遇到的错误：

> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake/alt_system.rb:32:
> Use RbConfig instead of obsolete and deprecated Config. (in
> /home/Roma/rails_projects/coise)
> ** Invoke db:migrate (first_time)
> ** Invoke environment (first_time)
> ** Execute environment
> ** Execute db:migrate rake aborted! could not connect to server: Connection refused
>         Is the server running on host "localhost" (127.0.0.1) and accepting
>         TCP/IP connections on port 5432? /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:928:in `initialize'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:928:in `new'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:928:in `connect'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:228:in `initialize'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:25:in
> `new'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:25:in
> `postgresql_connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:230:in
> `new_connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:238:in
> `checkout_new_connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:194:in
> `block (2 levels) in checkout'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in
> `loop'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:190:in
> `block in checkout' /usr/lib/ruby/1.9.1/monitor.rb:211:in
> `mon_synchronize'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:189:in
> `checkout'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:96:in
> `connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_pool.rb:318:in
> `retrieve_connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:97:in `retrieve_connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:89:in `connection'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/migration.rb:486:in
> `initialize'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/migration.rb:433:in
> `new'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/migration.rb:433:in
> `up'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/migration.rb:415:in
> `migrate'
> /usr/lib/ruby/gems/1.9.1/gems/activerecord-3.0.1/lib/active_record/railties/databases.rake:142:in
> `block (2 levels) in <top (required)>'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:636:in `call'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:636:in `block in
> execute' /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:631:in
> `each' /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:631:in
> `execute' /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:597:in
> `block in invoke_with_call_chain'
> /usr/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:590:in
> `invoke_with_call_chain'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:583:in `invoke'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2051:in
> `invoke_task'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `block (2
> levels) in top_level'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `each'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2029:in `block in
> top_level'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2068:in
> `standard_exception_handling'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2023:in
> `top_level'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2001:in `block in
> run' /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:2068:in
> `standard_exception_handling'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/lib/rake.rb:1998:in `run'
> /usr/lib/ruby/gems/1.9.1/gems/rake-0.8.7/bin/rake:31:in `<top
> (required)>' /usr/bin/rake:23:in `load' /usr/bin/rake:23:in `<main>'

我现在真的不知道该怎么办。我还将展示我的 database.yml 文件（根据我在搜索时遇到的提示进行的一些更改）：

development:
  adapter: postgresql
  encoding: unicode
  database: coise_development
  pool: 5
  username: coise
  password:
  host: localhost
  port: 5432

test:
  adapter: postgresql
  encoding: unicode
  database: coise_test
  pool: 5
  username: coise
  password:
  host: localhost
  port: 5432

production:
  adapter: postgresql
  encoding: unicode
  database: coise_production
  pool: 5
  username: coise
  password:

Answer 1

我已经取得了进步。通过这篇 StackOverflow 帖子 - 在 Cygwin 中启用 Postgresql - 我能够启动并运行我的 PostGreSql 服务。最后，我所要做的就是根据 PostGreSql 服务启动的用户更改我的 database.yml 文件用户名和数据库字段，在我的例子中是“Roma”。

最后，命令

rake db:migrate

没有遇到任何问题，就像我推送到heroku一样，完美无缺。我唯一仍然不明白的是 Heroku 托管，因为我的用户页面（我使用 Rails

scaffold

命令添加的表）尚不可用。我的 Heroku 告诉我我应该有更多的“Dynos”并升级到“生产 Postgresql 数据库”。我不确定这是否意味着托管需要一段时间才能完成，或者我的应用程序实际上是否有任何问题，但我不得不说生成的数据库非常基本且简单。