mysql - ruby 无法连接 MySQL

Question

我是 ruby​​ on Rails 的新手，我正在尝试让它与 MySQL 一起使用。我使用brew install mysql安装了mysql，然后安装了gem mysql2，但没有任何效果。我已经解决了这里的所有问题，但似乎没有任何效果。这是我的数据库.yml

    # MySQL.  Versions 5.0+ are recommended.
      #
      # Install the MYSQL driver
      #   gem install mysql2
      #
      # Ensure the MySQL gem is defined in your Gemfile
      #   gem 'mysql2'
      #
      # And be sure to use new-style password hashing:
      #   http://dev.mysql.com/doc/refman/5.0/en/old-client.html
      #
      default: &default
        adapter: mysql2
        encoding: utf8
        pool: 5
        username: root
        password:
        host: localhost

      development:
        <<: *default
        database: optimus_development

      # 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: optimus_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="mysql2://myuser:mypass@localhost/somedatabase"
      #
      # You can use this database configuration with:
      #
      #   production:
      #     url: <%= ENV['DATABASE_URL'] %>
      #
      production:
        <<: *default
        database: optimus_production
        username: optimus
        password: <%= ENV['OPTIMUS_DATABASE_PASSWORD'] %>

这是我尝试在浏览器中运行它时遇到的错误:

Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

我尝试将 localhost 更改为 127.0.0.1，但这不起作用。任何帮助将不胜感激

我在阅读下面可能重复的链接后启动了我的服务器，现在我收到此消息:

          Unknown database 'optimus_development'Run `$ bin/rake db:create db:migrate` to create your database

Answer 1

确保您的 MySQL 服务器已启动:

Apple Menu > System Preferences > MySQL > Start MySQL Server