我尝试使用postgresql数据库创建rails应用程序，但是当我创建数据库rake db:migrate时bash显示错误
FATAL: role "my" does not exist
如何解决？
抱歉我的英文不好
UPD
my@my-P5K-SE ~/ror/timonin $ rake db:create
FATAL: role "my" does not exist
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:898:in `rescue in connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:568:in `initialize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:87:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:88:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:102:in `block in create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:209:in `block in each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:101:in `create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `load'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `<main>'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "pool"=>5, "database"=>"timonin_development"}
FATAL: role "my" does not exist
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:898:in `rescue in connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:888:in `connect'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:568:in `initialize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `new'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:435:in `new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:445:in `checkout_new_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:416:in `acquire_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:351:in `block in checkout'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:350:in `checkout'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_adapters/abstract/connection_pool.rb:541:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:113:in `retrieve_connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/connection_handling.rb:87:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:8:in `connection'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:17:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:88:in `create'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:102:in `block in create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:209:in `block in each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:208:in `each_current_configuration'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/tasks/database_tasks.rb:101:in `create_current'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.4/lib/active_record/railties/databases.rake:17:in `block (2 levels) in <top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `call'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:240:in `block in execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:235:in `execute'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:179:in `block in invoke_with_call_chain'
/usr/local/rvm/rubies/ruby-2.1.3/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:172:in `invoke_with_call_chain'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/task.rb:165:in `invoke'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:150:in `invoke_task'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:106:in `block in top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:115:in `run_with_threads'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:100:in `top_level'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:78:in `block in run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:176:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/lib/rake/application.rb:75:in `run'
/usr/local/rvm/gems/ruby-2.1.3/gems/rake-10.3.2/bin/rake:33:in `<top (required)>'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `load'
/usr/local/rvm/gems/ruby-2.1.3/bin/rake:23:in `<main>'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `eval'
/usr/local/rvm/gems/ruby-2.1.3/bin/ruby_executable_hooks:15:in `<main>'
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "pool"=>5, "database"=>"timonin_test"}
的database.yml
# PostgreSQL. Versions 8.2 and up are supported.
#
# Install the pg driver:
# gem install pg
# On OS X with Homebrew:
# gem install pg -- --with-pg-config=/usr/local/bin/pg_config
# On OS X with MacPorts:
# gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
# On Windows:
# gem install pg
# Choose the win32 build.
# Install PostgreSQL and put its /bin directory on your path.
#
# Configure Using Gemfile
# gem 'pg'
#
default: &default
adapter: postgresql
encoding: unicode
# For details on connection pooling, see rails configuration guide
# http://guides.rubyonrails.org/configuring.html#database-pooling
pool: 5
development:
<<: *default
database: timonin_development
# The specified database role being used to connect to postgres.
# To create additional roles in postgres see `$ createuser --help`.
# When left blank, postgres will use the default role. This is
# the same name as the operating system user that initialized the database.
#username: timonin
# The password associated with the postgres role (username).
#password:
# Connect on a TCP socket. Omitted by default since the client uses a
# domain socket that doesn't need configuration. Windows does not have
# domain sockets, so uncomment these lines.
#host: localhost
# The TCP port the server listens on. Defaults to 5432.
# If your server runs on a different port number, change accordingly.
#port: 5432
# Schema search path. The server defaults to $user,public
#schema_search_path: myapp,sharedapp,public
# Minimum log levels, in increasing order:
# debug5, debug4, debug3, debug2, debug1,
# log, notice, warning, error, fatal, and panic
# Defaults to warning.
#min_messages: notice
# 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: timonin_test
# As with config/secrets.yml, you never want to store sensitive information,
# like your database password, in your source code. If your source code is
# ever seen by anyone, they now have access to your database.
#
# Instead, provide the password as a unix environment variable when you boot
# the app. Read http://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full rundown on how to provide these environment variables in a
# production deployment.
#
# On Heroku and other platform providers, you may have a full connection URL
# available as an environment variable. For example:
#
# DATABASE_URL="postgres://myuser:mypass@localhost/somedatabase"
#
# You can use this database configuration with:
#
# production:
# url: <%= ENV['DATABASE_URL'] %>
#
production:
<<: *default
database: timonin_production
username: timonin
password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %>
答案 0 :(得分：3)
在我的Ruby on Rails安装中使用Ubuntu 14.04 LTS时遇到了同样的问题。问题是我没有为我的postgres数据库创建一个用户，所以我做了以下操作并且它有效。
＃1以默认用户身份登录
$ sudo su postgres
＃2登录postgres互动终端
PSQL
或者，您可以按如下方式组合步骤＃1和＃2：
$ sudo su postgres psql
＃3查看postgres互动终端中的角色列表
postgres =＃\ du
＃4在postgres数据库中创建角色
postgres =＃CREATE user with password'';
＃5让您刚刚创建超级用户的用户
postgres =＃alter user with superuser;
＃6从postgres控制台退出
postgres =＃\ q
答案 1 :(得分：2)
您可以使用显式（my即操作系统用户名）或隐式（timonin即database.yml中的角色）登录连接到Postgres服务器。
我看到您的database.yml有用户名声明，但仅用于制作环境。默认情况下，在未指定Rails环境的情况下运行rake测试将针对 development 环境运行它们。这就是为什么你有FATAL: role "my" does not exist的错误。
因此，根据您的需要，您必须将这些语句添加到所有数据库中。防御（test和development）：
username: timonin
password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %>
之后，您的Rails应用程序将以timonin用户身份连接。
完整清单如下：
这是PostgreSQL的SQL：
CREATE ROLE timonin LOGIN PASSWORD 'Pas$_sword'
NOINHERIT CREATEDB
VALID UNTIL 'infinity';
COMMENT ON ROLE timonin
IS 'Timonin database role for Rails app';
username: timonin和password: <%= ENV['TIMONIN_DATABASE_PASSWORD'] %>到您的database.yml文件TIMONIN_DATABASE_PASSWORD变量这里改变了rake命令：
rake db:create TIMONIN_DATABASE_PASSWORD='Pas$_sword'
或：
rake db:create TIMONIN_DATABASE_PASSWORD='Pas$_sword' RAILS_ENV=test
用于测试环境。