Rails 3 Mysql Problems

Question

Trying to start a new Rails 3 beta 4 app with mysql.... Running OS X Snow Leopard. WIth previous versions of Rails I have no problem with MySQL. But now when I start the Rails 3 app I get the following error when I click "About Your Application Environment" on the Rails index.html startup screen:

undefined method `init' for Mysql:Class

Answer 1

Change your Gemfile to use 'mysql2', it's a more modern driver and has nicer features as other people have mentioned.

New Rails applications use the mysql2 gem by default.

Answer 2

I ran into the same issue (RoR 3, OSX 10.6, mysql 2.8.1 gem).

You can use irb to rule out RoR:

irb
require 'rubygems'
require 'mysql'
db = Mysql.connect('hostname', 'username', 'password', 'database')

If the above doesn't work, you may want to try removing the mysql gem and reinstalling it. I came across a post saying bundle install might mess up the install without displaying errors.

sudo gem uninstall mysql
sudo env ARCHFLAGS="-arch x86_64" gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

Verify things work via irb, then start up rails again.

Answer 3

I ended up switching from the mysql gem to the ruby-mysql gem, worked.