rails cannot load such file ― mysql2/mysql2 (LoadError)

问题:

I am newbie to ruby on rails i could not find the solution for this error:

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>' 

回答1:

gem uninstall mysql2  gem install mysql2 --platform=ruby 

delete the mysql2 gem directory in your rails specific bundle directory and copy paste this newly install mysql2 gem

回答2:

For Rails 3.2.17 and Ruby 1.9.3-p448 and mysql2 0.3.11, running bundle update mysql2 updated to 0.3.15 and got rid of the error for me.

回答3:

Ya, It's happening with new version(0.3.13) of mysql2 gem with rails 4.0.0. Deleting the bundle folder under vendor directory, and rerunning bundle install, update fixed this issue for me

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

回答4:

Do you have the mysql2 gem installed? Check that your gemfile has gem "mysql2" and then run bundle install from the root of your rails app. Also, ensure that you mysql downloaded in your development environment.

回答5:

just downgrade the mysql2 version. In my case, I used '0.2.6' version and it worked for me.

  gem 'mysql2', '0.2.6' 

with ruby version 2.0.0 and gem version 1.8.25

回答6:

this solved my error:

[root@localhost cms]# su Harish

[Harish@localhost cms]$ bundle install

[Harish@localhost cms]$ rails s

文章来源: rails cannot load such file ― mysql2/mysql2 (LoadError)