rake aborted! uninitialized constant Mysql2

Question

Goksel-Eryigits-Mac-mini:blog geryit$ rake db:migrate --trace
(in /Users/geryit/Sites/blog)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:migrate
rake aborted!
Client does not support authentication protocol requested by server; consider upgrading MySQL client
/Users/geryit/.rvm/rubies/ruby-1.8.7-p330/lib/ruby/1.8/mysql.rb:453:in `read'
/Users/geryit/.rvm/rubies/ruby-1.8.7-p330/lib/ruby/1.8/mysql.rb:130:in `real_connect'
/Users/geryit/.rvm/gems/ruby-1.8.7-p330/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:600:in `connect'
/Users/geryit/.rvm/gems/ruby-1.8.7-p330/gems/activerecord-3.0.3/lib/active_record/connection_adapters/mysql_adapter.rb:164:in `initialize
.
.
.

database.yml

development:
  adapter: mysql
  encoding: utf8
  database: test
  pool: 5
  username: root
  password:
  socket: /tmp/mysql.sock

Answer 1

Have you defined

gem 'mysql2'

in Gemfile? For Rails 3 and Bundler, it's not enough to install the gem, but to include it in Gemfile.

Answer 2

They work together now without any problems. The problem was Mysql version and mysql gem flags. I removed MYSQL 5.5 and installed Mysql 5.1 back. Everything is fixed. Thanks.

I wrote a blog post about installing, it can be helpful : https://geryit.com/blog/installing-mysql-with-rails-on-mac-os-x-snow-leopard/

Answer 3

Try uninstalling the mysql gem. It might be conflicting with the mysql2 gem you're using in your database.yml .

Answer 4

我在Snow Leopard和Rails 3上获得了“未初始化的常量Mysql”。在Gemfile中添加“mysql”gem为我修复了它。