RuntimeError with mysql2 and rails3 (bundler)

Question

I get this error

`establish_connection\': Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (no such file to load -- active_record         


        

Answer 1

If anybody still facing problem of installing mysql2 gem with rails 3 on Windows, then refer to the detailed steps of installation on -

http://rorguide.blogspot.com/2011/03/installing-mysql2-gem-on-ruby-192-and.html

Answer 2

This also fixed the issue I had with:

Please install the mysql2 adapter: `gem install activerecord-mysql2-adapter` (no such file to load -- active_record/connection_adapters/mysql2_adapter)

You actually need to run: gem install mysql2 and add the gem to your config.

Answer 3

I had the same error after upgrading from Ubuntu 11.10 to 12.04. This is how I fixed the problem:

gem uninstall mysql2
bundle

I think the key here is the 'native extensions' -- I suppose when I installed last, I was using a different version of mysql.

Installing mysql2 (0.3.11) with native extensions

Answer 4

Also need to change adapter from mysql to mysql2 in database.yml as said here Install mysql2 gem on Snow Leopard for Rails 3 with rvm

From:

development: adapter: mysql

To:

development: adapter: mysql2

Answer 5

Same issue for me too. Upgraded to Rails 3.1.rc4 then downgraded to 3.0.3. Worked for me.