【发布时间】：2025-11-27 08:00:01
【问题描述】：
我最近通过brew升级到最新版本的mysql：
$ mysql -V
mysql Ver 8.0.11 for osx10.13 on x86_64 (Homebrew)
现在我的 Ruby on Rails mysql 连接停止工作了。
为了与生产环境兼容，我必须使用gem 'mysql', '2.8.1'，并且在更新之前一切都运行良好。更新 mysql 后，我收到以下错误消息：
$ rails s
=> Booting WEBrick
=> Rails 3.2.5 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
SECURITY WARNING: No secret option provided to Rack::Session::Cookie.
This poses a security threat. It is strongly recommended that you
provide a secret to prevent exploits that may be possible from crafted
cookies. This will not be supported in future versions of Rack, and
future versions will even invalidate your existing user cookies.
Called from: /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/actionpack-3.2.5/lib/action_dispatch/middleware/session/abstract_store.rb:28:in `initialize'.
Exiting
/Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/mysql_adapter.rb:32:in `mysql_connection': undefined method `init' for Mysql:Class (NoMethodError)
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:309:in `send'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:309:in `new_connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:319:in `checkout_new_connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:241:in `checkout'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `loop'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:236:in `checkout'
from /Users/MyAccount/.rvm/rubies/ruby-version/lib/ruby/1.8/monitor.rb:242:in `synchronize'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:233:in `checkout'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:96:in `connection'
from /Users/MyAccount/.rvm/rubies/ruby-version/lib/ruby/1.8/monitor.rb:242:in `synchronize'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:95:in `connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:404:in `retrieve_connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:168:in `retrieve_connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/connection_adapters/abstract/connection_specification.rb:142:in `connection'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/model_schema.rb:308:in `clear_cache!'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activerecord-3.2.5/lib/active_record/railtie.rb:97:in `_callback_before_13'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:418:in `_run__1580337521__prepare__4__callbacks'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:405:in `send'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:405:in `__run_callback'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:81:in `send'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/callbacks.rb:81:in `run_callbacks'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/actionpack-3.2.5/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/actionpack-3.2.5/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/application/finisher.rb:47
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/initializable.rb:30:in `instance_exec'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/initializable.rb:30:in `run'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/initializable.rb:55:in `run_initializers'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/initializable.rb:54:in `each'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/initializable.rb:54:in `run_initializers'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/application.rb:136:in `initialize!'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/railtie/configurable.rb:30:in `send'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/railties-3.2.5/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /Users/MyAccount/Development/REPRO/webapp/config/environment.rb:9
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/dependencies.rb:251:in `gem_original_require'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/dependencies.rb:251:in `require'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/dependencies.rb:251:in `require'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/dependencies.rb:236:in `load_dependency'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/activesupport-3.2.5/lib/active_support/dependencies.rb:251:in `require'
from /Users/MyAccount/Development/REPRO/webapp/config.ru:3
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/rack-1.4.7/lib/rack/builder.rb:51:in `instance_eval'
from /Users/MyAccount/.rvm/gems/ruby-version@webapp/gems/rack-1.4.7/lib/rack/builder.rb:51:in `initialize'
from /Users/MyAccount/Development/REPRO/webapp/config.ru:0:in `new'
from /Users/MyAccount/Development/REPRO/webapp/config.ru:0
我该如何解决这个问题？有没有办法解决mysql连接问题？
很遗憾，mysql2 不适用于生产环境。
更新mysql版本：
$ brew info mysql
mysql: stable 8.0.11 (bottled)
Open source relational database management system
https://dev.mysql.com/doc/refman/8.0/en/
Conflicts with:
mariadb (because mysql, mariadb, and percona install the same binaries.)
mariadb-connector-c (because both install plugins)
mysql-cluster (because mysql, mariadb, and percona install the same binaries.)
mysql-connector-c (because both install MySQL client libraries)
percona-server (because mysql, mariadb, and percona install the same binaries.)
/usr/local/Cellar/mysql/5.7.21 (323 files, 233.9MB)
Poured from bottle on 2018-02-21 at 14:26:22
/usr/local/Cellar/mysql/8.0.11 (254 files, 232.6MB) *
Poured from bottle on 2018-06-22 at 06:21:48
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/mysql.rb
==> Dependencies
Build: cmake ✔
Required: openssl ✔
==> Requirements
Required: macOS >= 10.10 ✔
==> Options
--with-debug
Build with debug support
--with-embedded
Build the embedded server
--with-local-infile
Build with local infile loading support
--with-memcached
Build with InnoDB Memcached plugin
--with-test
Build with unit tests
==> Caveats
We've installed your MySQL database without a root password. To secure it run:
mysql_secure_installation
MySQL is configured to only allow connections from localhost by default
To connect run:
mysql -uroot
To have launchd start mysql now and restart at login:
brew services start mysql
Or, if you don't want/need a background service you can just run:
mysql.server start
5.7.21 一切正常。
【问题讨论】：
标签： mysql ruby-on-rails ruby-on-rails-3 ruby-on-rails-3.2