请安装mysql适配器'gem install activerecord-mysql-adapter'
我很难find解决这个问题的方法。 我收到错误：
Please install the mysql adapter: 'gem install activerecord-mysql-adapter' /Users/ Andy/.rvm/gems/ruby-1.9.2-p290@global/gems/bundler-1.0.21/lib/bundler/rubygems_integration.rb:143:in `block in replace_gem': Please install the mysql adapter: `gem install activerecord-mysql-adapter` (mysql is not part of the bundle. Add it to Gemfile.) (LoadError) from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/mysql_adapter.rb:5:in `<top (required)>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `block in require' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:236:in `load_dependency' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:48:in `resolve_hash_connection' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:39:in `resolve_string_connection' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:23:in `spec' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/connection_adapters/abstract/connection_specification.rb:127:in `establish_connection' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/railtie.rb:76:in `block (2 levels) in <class:Railtie>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/lazy_load_hooks.rb:26:in `on_load' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activerecord-3.2.1/lib/active_record/railtie.rb:74:in `block in <class:Railtie>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:30:in `instance_exec' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:30:in `run' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:55:in `block in run_initializers' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:54:in `each' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/initializable.rb:54:in `run_initializers' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/application.rb:136:in `initialize!' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/railtie/configurable.rb:30:in `method_missing' from /Users/ Andy /config/environment.rb:5:in `<top (required)>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `block in require' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:236:in `load_dependency' from /Users/ Andy /mysql2/ruby/1.9.1/gems/activesupport-3.2.1/lib/active_support/dependencies.rb:251:in `require' from /Users/ Andy /config.ru:4:in `block in <main>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `instance_eval' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:51:in `initialize' from /Users/ Andy /config.ru:1:in `new' from /Users/ Andy /config.ru:1:in `<main>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in `eval' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/builder.rb:40:in `parse_file' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:200:in `app' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/commands/server.rb:46:in `app' from /Users/ Andy/mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:301:in `wrapped_app' from /Users/ Andy /mysql2/ruby/1.9.1/gems/rack-1.4.1/lib/rack/server.rb:252:in `start' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/commands/server.rb:70:in `start' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:55:in `block in <top (required)>' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:50:in `tap' from /Users/ Andy /mysql2/ruby/1.9.1/gems/railties-3.2.1/lib/rails/commands.rb:50:in `<top (required)>' from script/rails:6:in `require' from script/rails:6:in `<main>' ``` 这是gem env输出。
RubyGems Environment: - RUBYGEMS VERSION: 1.8.15 - RUBY VERSION: 1.9.2 (2011-07-09 patchlevel 290) [x86_64-darwin11.2.0] - INSTALLATION DIRECTORY: /Users/ Andy/.rvm/gems/ruby-1.9.2-p290 - RUBY EXECUTABLE: /Users/ Andy/.rvm/rubies/ruby-1.9.2-p290/bin/ruby - EXECUTABLE DIRECTORY: /Users/ Andy/.rvm/gems/ruby-1.9.2-p290/bin - RUBYGEMS PLATFORMS: - ruby - x86_64-darwin-11 - GEM PATHS: - /Users/ Andy/.rvm/gems/ruby-1.9.2-p290 - /Users/ Andy/.rvm/gems/ruby-1.9.2-p290@global - GEM CONFIGURATION: - :update_sources => true - :verbose => true - :benchmark => false - :backtrace => false - :bulk_threshold => 1000 - REMOTE SOURCES: - http://rubygems.org/
如果我可以提供更多的信息，请让我知道。
谢谢， – 安迪
Ps – 我的database.yaml已经有了mysql2 。
问题出在你的文件config / database.yml上
你应该有一行指定适配器是mysql2（而不是mysql）
adapter: mysql2
代替
adapter: mysql
什么帮助我指定适配器mysql2而不是MySQL（注意数字！）在config / database.yml中。
我从来不会相信，但删除我的database.yml文件，并重新创build它实际上也解决了我的问题。 谢谢泰勒。 我花了几个小时安装和卸载不同版本的gemmysql，mysql2，activerecord-mysql-adapter等…最后，我的gemfile有
gem 'mysql2', "~>0.3.11"
和我的database.yml文件
adapter: mysql2
我在OSX 10.8，轨3.2.8和ruby1.9.3。
顺便说一句，我遇到了与我的Windows 7机器上的mysql2适配器相同的问题。 卸载甚至删除activerecord-mysql-adapter gem的目录似乎也很重要。
1）您需要更新您的config/database.yml文件并更改：
adapter: mysql
成
adapter: mysql2
2）你需要更新你的Gemfile并显式地添加activerecord-mysql2-adapter依赖关系：
gem 'mysql2' gem 'activerecord-mysql2-adapter'
你想安装mysql2gem 。
真的，你应该把它添加到你的Gemfile ：
gem "mysql2"
然后用bundler安装你的gem：
bundle install
升级到Rails 3.2后，我遇到了和OSX Lion上的OP一样的问题。 删除所有的gem，捆绑安装等没有工作。 Gemfile和database.yml正确地指定了mysql2。
最后，我删除并重新创build我的database.yml和一切工作。 这可能是文件中的错字或隐藏字符。
第1步： gem 'mysql2', "~>0.3.11"而不是Gem'mysql2 gem 'mysql2'在Gemfile中
第二步 C:\wamp\bin\mysql\mysql5.5.24\lib在C:\ruby2.0.0\bin文件夹下放置mysqllib.dll （可在mysql安装C:\wamp\bin\mysql\mysql5.5.24\lib ）解决rake db:migrate问题，并成功连接我的rails用mysql（ database.yml包含mysql2）
我正在运行的Windows 7,64位，MySQL的64位，ruby2.0.0 [x64-mingw32]
谢谢大家的投入。
这可能会迟到，但捆绑安装是安装0.4.0所以我试图编辑gem文件 ，我用mysql2replace
gem 'mysql2', "~>0.3.11"
接着
bundle install
在terminal（这将安装mysql2 0.3.11，而不是最后一个版本）我认为积极的logging有问题的最后一个版本。 那么我希望它有帮助
您可能已经将适配器更改为针对特定环境的mysql2，但不会将该环境传递给rake命令。
例如我只在生产环境中将mysql更改为mysql2，但正在运行
rake generate_secret_token
当我改变它到以下它的工作：
rake generate_secret_token RAILS_ENV=production
如果没有任何帮助（你的database.yml有mysql2作为适配器）并且你正在使用RVM来pipe理你的ruby版本，这里是最简单的解决scheme：
尝试删除所有的旧的gemsets（包括global ），安装一个新的ruby版本，并再次捆绑。 我可以这样解决问题。
你已经提到你的database.yaml文件已经有mysql2 。
它值得检查是否安装了activerecord-mysql2-adapter 。 （注-mysql2- ）
我会说，改变在database.yml顶部的评论信息
# # Install the MYSQL driver # gem install mysql2 # # Ensure the MySQL gem is defined in your Gemfile # gem 'mysql2' # # And be sure to use new-style password hashing: # http://dev.mysql.com/doc/refman/5.0/en/old-client.html
第二：在gemfile中添加“gem'mysql2'”（双引号里面的东西）。
保存一切，做捆绑安装。 希望有所帮助。
或者它可能是一个错字。
我遇到同样的问题，并得到同样的错误，当运行命令
gem install activerecord-mysql2-adapter
您需要安装libmysqlclient-dev
sudo apt-get install libmysqlclient-dev
这个对我有用
在我的情况下，当我也得到这个错误：
耙中止！ 请安装mysql适配器：
gem install activerecord-mysql-adapter（mysql不是该软件包的一部分，将它添加到Gemfile中）
在我search了Google并尝试了很多方法之后，这并没有奏效。 最后，答案是
- 导航到您的应用程序的根目录，运行
open gemfile - 在rails的gem行正下方添加行
gem 'mysql2', '< 0.3.7'。
我只是将以下行添加到我的Gemfile它工作：
gem“mysql”
之前：
source 'https://rubygems.org' gem "rails", "3.2.16" gem "jquery-rails", "~> 2.0.2" gem "coderay", "~> 1.1.0" gem "fastercsv", "~> 1.5.0", :platforms => [:mri_18, :mingw_18, :jruby] gem "builder", "3.0.0" ...
后：
source 'https://rubygems.org' gem "mysql" gem "rails", "3.2.16" gem "jquery-rails", "~> 2.0.2" gem "coderay", "~> 1.1.0" gem "fastercsv", "~> 1.5.0", :platforms => [:mri_18, :mingw_18, :jruby] gem "builder", "3.0.0" ...
