rails无法加载这样的文件-- mysql2 2/mysql2 2 (LoadError)

Question

我是ruby on rails的新手，我找不到解决这个错误的方法：

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创业板目录，并复制粘贴这个新安装的mysql2创业板

Answer 2

对于Rails 3.2.17和Ruby1.9.3-p448和mysql2 0.3.11，运行bundle update mysql2更新为0.3.15，并为我消除了错误。

Answer 3

Ya，这发生在rails 4.0.0的mysql2 gem的新版本(0.3.13)中。删除供应商目录下的bundle文件夹，并重新运行bundle安装，更新此问题。

cd {Your_RailsApp_Root}/vendor/
rm -rf bundle/
cd {Your_RailsApp_Root}
bundle install
bundle update