ruby-on-rails - 安装 mysql2 gem 错误

Question

我通过macport安装了ruby和ruby gems，但是gem列表不包括mysql2。那么我如何将 mysql2 gem 安装在“/opt/local/bin/gem”内的 gem 列表中

另外，mysql2 gem 是什么？我有 mysql gem，只想使用 mysql，不太确定 mysql2 意味着什么。当我尝试在应用程序上启动 webrick 时，它给出了 mysql2 错误。

更新: 我运行 sudo gem install mysql2 并得到以下结果:

Building native extensions. This could take a while... Successfully installed mysql2-0.2.7 1 gem installed Installing ri documentation for mysql2-0.2.7...

Enclosing class/module 'mMysql2' for class Client not known

Enclosing class/module 'mMysql2' for class Result not known Installing RDoc documentation for mysql2-0.2.7...

Enclosing class/module 'mMysql2' for class Client not known

Enclosing class/module 'mMysql2' for class Result not known

假设安装了 mysql2，即使文档没有，当我尝试在我的应用程序中启动 webrick 时，我收到以下错误。

rails 服务器:

/opt/local/lib/ruby/gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle: dlopen(/opt/local/lib/ruby/gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.18.dylib (LoadError)
Referenced from: /opt/local/lib/ruby/gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle Reason: image not found - /opt/local/lib/ruby/gems/1.8/gems/mysql2-0.2.7/lib/mysql2/mysql2.bundle from /opt/local/lib/ruby/gems/1.8/gems/mysql2-0.2.7/lib/mysql2.rb:8 from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in require' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:64:in require' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in each' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:62:in require' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in each' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler/runtime.rb:51:in require' from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.7/lib/bundler.rb:112:in require' from /Users/summer/Sites/simple_cms/config/application.rb:7 from /opt/local/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands.rb:28:in require' from /opt/local/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands.rb:28 from /opt/local/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands.rb:27:in tap' from /opt/local/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands.rb:27 from script/rails:6:inrequire' from script/rails:6

Answer 1

据我所知，两个 gem(mysql 和 mysql2)之间的区别之一是 mysql2 在 UTF-8 下工作得更好。这里is an article关于它。

要安装 mysql2 gem，只需运行:

gem install 'mysql2'