rails mysql适配器错误

我很难找到解决这个问题的办法。我发现了错误

请安装mysql适配器：“gem安装activerecord mysql适配器”

当我在我的

Gemfile

中指定

ruby-mysql

或

mysql2

时。这只发生在我升级到Rails 3.1.0-rc1之后。我正在运行OSX10.6和Ruby1.9.2

cody$ rails c
/Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:71:in `rescue in establish_connection': Please install the mysql adapter: `gem install activerecord-mysql-adapter` (mysql is not part of the bundle. Add it to Gemfile.) (RuntimeError)
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:68:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:60:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:55:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/railtie.rb:69:in `block (2 levels) in <class:Railtie>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:42:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/base.rb:2135:in `<top (required)>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/railtie.rb:34:in `block in <class:Railtie>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `call'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `block in load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application.rb:115:in `block in load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application/railties.rb:8:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application/railties.rb:8:in `all'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application.rb:115:in `load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands/console.rb:26:in `start'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands/console.rb:8:in `start'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands.rb:40:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

---

我不得不强制使用mysql2 gem版本0.2.7，在尝试将我的rails 3.0.7应用程序升级到3.1.0.rc1时，我还注意到，您的gem文件中也需要以下新的gem：

gem 'mysql2', '< 0.3' # as stated above

# Asset template engines
gem 'json'
gem 'sass'
gem 'coffee-script'
gem 'uglifier'
# other required things for rails 3.1
gem 'jquery-rails'
gem 'mustang' # this is ONE execjs backend of many, and the only one that worked for me.

gem'mysql2'，“<0.3”#如上所述
#资产模板引擎
gem'json'
宝石“sass”
宝石“咖啡脚本”
“丑”宝石
#rails 3.1所需的其他内容
gem'jqueryrails'
gem‘mustang’#这是众多execjs后端之一，也是唯一一款适合我的。

---

告诉我这是否对您有效。

您必须更改

config/database.yml

以使用

mysql2

适配器，而不是

mysql

因此，请替换：

adapter: mysql

与：

---

通过更新我的应用程序的gemfile以将mysql2标识为捆绑包的一部分，修复了该问题

要执行此操作，请导航到应用程序的根目录，运行

open-gemfile

在rails的gem行的正下方添加一行“

gem'mysql2'，”<0.3.7'

在应用程序根目录下的终端中，运行

bundle install

运行

bundle show mysql2

验证bundle是否工作。现在就可以使用适配器了

---

我的环境是Rails 3.1、MySql 5.5、Ruby 1.9.2。

我在windows上创建了一个Rails项目，并将其移动到运行Fedora的机器上。我通过将“Gemfile.lock”重命名为“old_Gemfile.lock”解决了这个问题。当然，您仍然必须将适配器指定为“mysql2”，并在gem文件中包含相应的gem。

我相信我已经解决了我的问题。我在数据库中设置了'adapter:mysql2'而不是'adapter:mysql'。yml我为这一噪音道歉。建议原始海报接受Brad Folkens的回答。向在Heroku上使用Amazon RDS插件的任何人发送通知，您需要进行此更改，还可以将RDS插件中的DB URL更改为使用

mysql2://

而不是

mysql://

，否则仍然会出现错误。是否有理由将gem版本限制为“<0.3”？

cody$ rails c
/Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:71:in `rescue in establish_connection': Please install the mysql adapter: `gem install activerecord-mysql-adapter` (mysql is not part of the bundle. Add it to Gemfile.) (RuntimeError)
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:68:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:60:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/connection_adapters/abstract/connection_specification.rb:55:in `establish_connection'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/railtie.rb:69:in `block (2 levels) in <class:Railtie>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:36:in `instance_eval'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:36:in `execute_hook'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:43:in `block in run_load_hooks'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:42:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activesupport-3.1.0.rc1/lib/active_support/lazy_load_hooks.rb:42:in `run_load_hooks'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/base.rb:2135:in `<top (required)>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.1.0.rc1/lib/active_record/railtie.rb:34:in `block in <class:Railtie>'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `call'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `block in load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/railtie.rb:177:in `load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application.rb:115:in `block in load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application/railties.rb:8:in `each'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application/railties.rb:8:in `all'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/application.rb:115:in `load_console'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands/console.rb:26:in `start'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands/console.rb:8:in `start'
from /Users/cody/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.1.0.rc1/lib/rails/commands.rb:40:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

adapter: mysql2