Please install mysql adapter 'gem install acti

Question

I'm having trouble finding a solution to this problem. I'm getting the error:

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>' ```

Here is the gem env output.

  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/

If I can provide any more information please let me know.

Thanks, -Andy

---

P.s - My database.yaml already has mysql2.

Answer 1

The problem is on your file config/database.yml

You should have a line that specify that the adapter is mysql2 (and not mysql)

adapter: mysql2

Instead of

adapter: mysql

Answer 2

What helped for me was specifying adapter mysql2 instead of mysql (note the digit!) in config/database.yml.

Answer 3

1) You need to update your config/database.yml file and change:

adapter: mysql

into

adapter: mysql2

2) You need to update your Gemfile and explicitly add activerecord-mysql2-adapter dependency there:

gem 'mysql2'
gem 'activerecord-mysql2-adapter'

Answer 4

I am facing the same issue and getting same error when run command

gem install activerecord-mysql2-adapter

you need to install libmysqlclient-dev

sudo apt-get install libmysqlclient-dev

It works for me