rails无法加载此类文件 - mysql2/mysql2(LoadError)

Question

我是ruby on rails的新手我无法找到此错误的解决方案:

rails s

---

/usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `require': cannot load such file -- mysql2/mysql2 (LoadError)
from /usr/local/share/gems/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `<top (required)>'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
from /usr/local/share/gems/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
from /home/Harish/Documents/simple_cms/config/application.rb:7:in `<top (required)>'
from /usr/local/share/gems/gems/railties-4.0.0/lib/rails/commands.rb:76:in `require'
from /usr/local/share/gems/gems/railties-4.0.0/lib/rails/commands.rb:76:in `block in <top (required)>'
from /usr/local/share/gems/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap'
from /usr/local/share/gems/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'

Answer 1

gem uninstall mysql2

gem install mysql2 --platform=ruby

删除rails特定包目录中的mysql2 gem目录并复制粘贴这个新安装的mysql2 gem

Answer 2

对于Rails 3.2.17和Ruby 1.9.3-p448和mysql2 0.3.11，运行bundle update mysql2更新为0.3.15，并为我摆脱了错误。

Answer 3

你安装了 mysql2 gem 吗？检查您的 gemfile 是否已包含gem "mysql2"，然后bundle install从 Rails 应用程序的根目录运行。另外，请确保您的开发环境中下载了 mysql。