Ruby on rails 错误：将sqlite3 db迁移到heroku上托管的rails应用程序的postgresql

我试图在heroku上托管我的rails应用程序，我最初设置的应用程序通常是sqlite3，因为我没有意识到它与heroku不兼容。我试图遵循railscast#342，但我不断地出现错误，不知道如何修复它们。当我运行命令时

bundle exec rake db:create

我得到一系列错误：

FATAL:  role "jen" does not exist
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/postgresql_adapter.rb:665:in `rescue in connect'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/postgresql_adapter.rb:655:in `connect'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/postgresql_adapter.rb:242:in `initialize'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `new'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/postgresql_adapter.rb:44:in `postgresql_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:438:in `new_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:448:in `checkout_new_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:422:in `acquire_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:349:in `block in checkout'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:348:in `checkout'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:263:in `block in connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:262:in `connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:571:in `retrieve_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/connection_handling.rb:87:in `connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:93:in `create'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:107:in `block in create_current'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:275:in `block in each_current_configuration'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:274:in `each'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:274:in `each_current_configuration'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/tasks/database_tasks.rb:106:in `create_current'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/activerecord-4.2.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:240:in `call'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:240:in `block in execute'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:235:in `each'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:235:in `execute'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/task.rb:165:in `invoke'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:150:in `invoke_task'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in `each'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:106:in `block in top_level'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:115:in `run_with_threads'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:100:in `top_level'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:78:in `block in run'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:176:in `standard_exception_handling'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/lib/rake/application.rb:75:in `run'
/Users/jen/.rbenv/versions/2.1.5/lib/ruby/gems/2.1.0/gems/rake-10.4.2/bin/rake:33:in `<top (required)>'
/Users/jen/.rbenv/versions/2.1.5/bin/rake:23:in `load'
/Users/jen/.rbenv/versions/2.1.5/bin/rake:23:in `<main>'

Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "database"=>"myapp_development", "pool"=>5, "username"=>"jen", "password"=>nil}

但它要求我输入一个我不知道的密码

更新：

这是我的database.yml文件：

# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
# default: &default
#   adapter: sqlite3
#   pool: 5
#   timeout: 5000

# development:
#   <<: *default
#   database: db/development.sqlite3

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
# test:
#   <<: *default
#   database: db/test.sqlite3

# production:
#   <<: *default
#   database: db/production.sqlite3

development:
  adapter: postgresql
  encoding: unicode
  database: mygaisce_development
  pool: 5
  username: jen
  password: secret

test:
  adapter: postgresql
  encoding: unicode
  database: mygaisce_test
  pool: 5
  username: jen
  password: secret

#SQLite版本3.x
#gem安装sqlite3
#
#确保在gem文件中定义了SQLite 3 gem
#gem'sqlite3'
#
#默认值：&默认值
#适配器：sqlite3
#游泳池：5
#超时：5000
#发展：
#生产中没有关于db的数据。
尝试添加

production:
  adapter: postgresql
  encoding: unicode
  pool: 5

在
database.yml
中，您很可能需要在postgres中创建一个jen用户。尝试
sudo-u postgres createuser--superuser jen
然后
sudo-u postgres psql
然后
\password jen
谢谢，但是我得到了错误
sudo:unknown user:postgres
你是如何安装postgres的？在我的笔记本电脑上，我以前安装它是为了一个不同的项目。这就是你的意思吗？对于这个项目，我使用了
gem安装pg
。我更新了上面的帖子，加入了我的database.yml文件。我不确定这是否是错误的来源。请使用您在其他项目中使用的相同数据库配置。
production:
  adapter: postgresql
  encoding: unicode
  pool: 5