ruby-on-rails - 无法使用带 Rails 的 PostgreSql 创建数据库

Question

我是一名初级 Web 开发人员，正在尝试开发我的第一个 Ruby on Rails 项目。我正在按照本指南在 render.com 上部署应用程序。

但是，在安装 rails 并按照此命令创建数据库后(我在 Ubuntu 上):

rails db:create

我在命令窗口遇到这个问题:

We could not find your database: postgres. Which can be found in the database configuration file located at config/database.yml.

To resolve this issue:

- Did you create the database for this app, or delete it? You may need to create your database.
- Has the database name changed? Check your database.yml config has the correct database name.

To create your database, run:

        bin/rails db:create
Couldn't create 'mysite_development' database. Please check your configuration.
rails aborted!
ActiveRecord::NoDatabaseError: We could not find your database: postgres. Which can be found in the database configuration file located at config/database.yml.

To resolve this issue:

- Did you create the database for this app, or delete it? You may need to create your database.
- Has the database name changed? Check your database.yml config has the correct database name.

To create your database, run:

        bin/rails db:create


Caused by:
PG::ConnectionBad: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: No such file or directory
    Is the server running locally and accepting connections on that socket?

它说我们找不到您的数据库。但是我在 config/database.yml 中有它:

# PostgreSQL. Versions 9.3 and up are supported.
#
# Install the pg driver:
#   gem install pg
# On macOS with Homebrew:
#   gem install pg -- --with-pg-config=/usr/local/bin/pg_config
# On macOS 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
  # https://guides.rubyonrails.org/configuring.html#database-pooling
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  database: mysite_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 running Rails.
  #username: mysite

  # 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: mysite_test

# As with config/credentials.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 or a full connection URL as an environment
# variable when you boot the app. For example:
#
#   DATABASE_URL="postgres://myuser:mypass@localhost/somedatabase"
#
# If the connection URL is provided in the special DATABASE_URL environment
# variable, Rails will automatically merge its configuration values on top of
# the values provided in this file. Alternatively, you can specify a connection
# URL environment variable explicitly:
#
#   production:
#     url: <%= ENV["MY_APP_DATABASE_URL"] %>
#
# Read https://guides.rubyonrails.org/configuring.html#configuring-a-database
# for a full overview on how database connection configuration can be specified.
#
production:
  <<: *default
  database: mysite_production
  username: mysite
  password: <%= ENV["MYSITE_DATABASE_PASSWORD"] %>

我该怎么办？我快要疯了。

我尝试了不同的命令:

        bin/rails db:create

也没有用。

Answer 1

错误消息表明服务器没有运行。

你有没有:

• 安装 PostgreSQL 软件包？
• 启动服务器？尝试运行:sudo systemctl 启动 postgresql