为什么我会收到“未加载库：libmysqlclient.18.dylib”错误？

Question

我一直在关注视频教程并创建了数据库，但是当尝试通过转到目录并输入 rake: dbmigrate 来执行该步骤时 我得到一个错误。

Ians-MacBook-Pro:music_library iansherwood$ rake db migrate
rake aborted!
dlopen(/Users/iansherwood/Sites/music_library/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2/mysql2.bundle, 9): Library not loaded: libmysqlclient.18.dylib
  Referenced from: /Users/iansherwood/Sites/music_library/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2/mysql2.bundle
  Reason: image not found - /Users/iansherwood/Sites/music_library/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2/mysql2.bundle
/Users/iansherwood/Sites/music_library/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `require'
/Users/iansherwood/Sites/music_library/vendor/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2.rb:8:in `<top (required)>'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:68:in `require'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:68:in `block (2 levels) in require'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:66:in `each'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:66:in `block in require'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:55:in `each'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler/runtime.rb:55:in `require'
/usr/local/rvm/gems/ruby-1.9.3-p392@global/gems/bundler-1.2.4/lib/bundler.rb:128:in `require'
/Users/iansherwood/Sites/music_library/config/application.rb:7:in `<top (required)>'
/Users/iansherwood/Sites/music_library/Rakefile:5:in `<top (required)>'
(See full trace by running task with --trace)

Answer 1

你试过bundle exec rake db:migrate吗？

另一种可能是您没有运行我的 MySQL。 最简单的检查方法是：

ps aux | grep mysql

如果它没有运行并且你安装了 MySQL homebrew（常用视频指导方式安装）然后你可以运行mysql.server start。

Answer 2

语法应该是：rake db:migrate，而不是rake: dbmigrate 或rake db migrate。

Answer 3

您的冒号使用似乎不一致。记得使用：

rake db:migrate

http://guides.rubyonrails.org/command_line.html

Answer 4

您是否在 Gemfile 中包含“gem 'mysql2'”？